Warmboard and Hydronic Radiant Floor Heating

From day one we wanted to have hydronic floor heating, our architect had used Warmboard before and seemed like a no-brainer over other approaches. 1 1/8″ plywood sub-floor with channels for 1/2″ PEX and a thin layer of aluminum on the top to her spread heat evenly. Looks like Warmboard offers a turnkey package now that includes heat loss analysis and an appropriate boiler, but we just got the system design, panels, tubing, and manifolds from them (through the architect as part of their package). Then our plumber helped us pick out a boiler and installed that and the tubing and manifolds and controls.

I think a fair number of people don’t bother with zones for hydronic heating, and with high efficiency condensing boilers they are most efficient when you don’t use a thermostat and just make your adjustments at the boiler, pretty much set it and forget it. But we like sleeping in a cool bedroom, having a toasty floor in the bathroom, and being able to dial back areas of the house we are not using (just two of us in the home), so we opted for five zones with thermostats, (1) master bedroom, (2) master bath, (3) living area, (4) upstairs bedrooms, and (5) upstairs loft. Warmboard produces a really nice set of plans and instructions that show the panel layout and also the tubing layout, highlighting where custom grooves/channels will have to be cut with a router (they provide templates). There was a little back and forth with Warmboard re zones, and also a panel layout adjustment to make sure channels were running perpendicular to joists in one room (1 1/8″ is more like 1/2″ at channels, so I don’t think you want those running parallel to floor joists).

Warmboard subfloor installed on main level, walls and partitions to second floor going in

Despite the fact that the architect was familiar with Warmboard there were a few issues with their installation of the subfloor panels. First, they used the plans provided by Warmboard as a general guide, but did not follow them closely, resulting in the need for additional routing of channels (adding cost and reducing effectiveness of the aluminum layer) and creating a couple of “cold spots.” Perhaps following an outdated set of plans they also installed a few panels with channels running parallel to the floor joists, I caught this and asked that they be pulled up and re-done. That required ordering some additional panels, which took some time to come and interrupted/complicated further work while we waited for those to come in. Finally, the installer ignored the Warmboard guidance that a 1/8″ gap should be left between the ends of the panels, the reason for which became clear later on as panels expanded and caused some buckling that did not subside. We still have some very noticeable high spots in the floors.

Warmboard provided layout did not include putting these loop turns under a wall plate …

Our construction manager was worried about hydronic (PEX) tubing getting damaged during installation, so we completed the interior (blown closed cell) insulation before tubing (a little under 3000′) was installed. After installation and testing we insulated under the main level, encasing the tubing below the subfloor in closed cell foam. We then protected the tubing by covering the floors with the cheapest 1/4″ 4×8 material we could find.

PEX tubing installed in living area, some custom routing around floor vent locations

For a boiler we selected a German engineered and made wall mounted Viessman Vitodens 200-W B2HB 57 (57 for roughly 57kW I think, which is about 200 kBTU, we did not do any formal heat loss calculations, I suspect it was overkill going with the largest version of this boiler). The boiler provides hot water to the hydronic heating system through a Viessman mixing valve and three circulators connected to three Warmboard manifolds. The manifolds seem quite nice, though the site glasses for flow rate adjustments get hard/impossible to see through pretty quickly. Each loop has a Stellantrieb 24 volt actuator that is controlled by one of two Taco ZVC403s, which are in turn controlled by five Nest thermostats (I failed to install wiring for these and construction manager/installer didn’t catch this, so we had to run wires after drywall was up, which was a pain).

Viessman boiler and hydronic heating system

As I mentioned before, the boiler could control everything if we only wanted to have one heating zone, with that approach you would not need the thermostats or Tacos or actuators, and you could still dial some areas of the home up or down by adjusting loop flow rates. The boiler has an outdoor temperature sensor and you tweak slop and offset to adjust a “heating curve” that determines how hot the water delivered to the hydronic heating system is. Each manifold has temperature gauges at input and output, so you can see how much the temperature is dropping, which indicates how much heat is being left in the area being heated. The installer did initially make a mistake with circulators for the hydronic system, with the manifolds having actuators that are opening and closing the circulators are deadheading, in some cases frequently/for extended periods of time. The solution was to install circulators that are designed to handle deadheading, in our case they used Grundfos ALPHA1s. I ordered a Vitoconnect 100 from a local supplier and installed it so I can monitor and control the boiler remotely (installer did not know much about Viessman equipment, a Viessman tech helped with some things, but I don’t think he really knew about remote monitoring/control either).

Vitodens heating curve, so when it is 32 degrees outside the boiler is delivering water that is 111 degrees to the manifolds

The boiler also feeds an 300 liter (79 gallon) Viessman Vitocell 100-V indirect water heater. The construction manager floated the idea of tankless water heaters, but then you need to plumb gas to those, where are you going to put them, and they are expensive. For me was simpler to just have an indirect tank that is large enough to fill up a bathtub. Indirect tanks are simple, super low maintenance, and last longer than a gas fired water heater, and are not too expensive (though ours was made in France).

There was a little bit of a learning curve with this equipment. Took me awhile to figure out that the hydronic system shuts down (power to circulators is cut) when the DHW loop kicks in. And when it is warm enough outside the power the the hydronic system circulators is shut off. The settings for the boiler are pretty extensive, I am sure all of this can be controlled/changed.

Then we had a couple of leaks that were bad enough to cause damage to the sheet rock in the garage area below the mechanical room. First leak was coming from the condensate drain line at the bottom of the boiler, and drove me crazy trying to figure out what was causing it, took lots of photos, took the boiler apart, calls to Viessman, etc. Turns out the problem was that the installer connected the drain line from the boiler directly to the neutralization box (our drains are PVC, not sure we really need the neutralization box, but at the very least we are being good citizens by not dumping acidic condensate into the sewer, and this boiler generates a lot of condensate).

Boiler condensate line reinstalled with air gap, per installation manual, mixing valve at top left, black box is a “radiator” for the hydronic system, tinfoil at lower right is temporary solution to second water leak, which was condensate from air handler heat exchanger bypassing the funnel and landing on the floor, then going to ceiling below
Installer should have RTFM

Plumbing Planning – Rough-In and Fixtures

Our construction manager got started with and was still running a plumbing business, so this was a pretty trouble free trade for us. We knew that we would have to pick out some things before the rough could start, and we were on top of that, and in addition to picking out things in most or maybe all cases we ordered fixtures and roughs and other so everything was on site and the plumber could proceed with the roughs.

First part of the rough in was waste lines. For that we had to finalize the location of toilets, sinks, bath tubs, showers, dishwasher, and washing machine. The plumber also coordinated with the sub putting in the heat pumps system (for condensate lines).

The architect plans were pretty close for all of this, but we did work with a kitchen designer on the kitchen design and while we were doing cabinets for the kitchen we increased the scope to include bathroom vanities and the laundry/mud room too, so we used adjustments that had been made in those drawings.

I guess I would describe the aesthetic we were going for as modern European, maybe a touch of Japanese minimalism, and choices here were mostly consistent with that.

Early on we decided to use wall-mounted toilets for three main reasons, (1) ease of cleaning, (2) clean look, and (3) ability to set any bowl at a comfortable height (we went with 16.5″ to rim, which is about 17.5″ to seat top, I am tall, wife is not so tall). After we doing some homework we settled on Toto Aquias, which appear to have been discontinued (wall-mounted version, anyway), but seemed to get good ratings for doing what they are supposed to do without extra fuss, and are elongated (and not rectangular, definitely not a fan of square toilets). I ordered them from supply.com (now Ferguson, my approach on fixtures was to figure out what we needed and order online for most things). Toto makes (or made?) an in-wall system/tank, but Geberit is the 800 lb gorilla in this space so we used Geberit in walls, ordering them from Amazon.

Geberit in-wall system/tank, master bath toilet is on exterior (2×6) wall so we added 2×6 framing for the carrier, losing some space I suppose, but the shelf above the toilet is actually quite handy

For consistency we used Toto sinks, same cotton color/glazing as the toilet bows. I initially ordered LT540G sinks, which are 21.25″x14″ undercounters, but when they arrived I realized they were enormous, so sent them back and ordered LT542G sinks, which are 19″x12.375″, which is a plenty big for our vanities, which are 22.25″ deep. Same sinks for the 2.5 baths, so four of them. These Toto sinks are a similar shape to the Kohler Ladena, which I liked and was ready to order (easy to clean/pleasing curved shape), but I figured might as well have the same glazing and as it turns out the Toto is available in a slightly smaller size that I think works better (I’d prefer to have a little extra vanity top space than a giant sink).

Undermount sink cutouts in master bath

While I am taking about sinks, for the kitchen we wanted a decent size single basin undermount stainless sink. We could have spent more money on a Franke, but the Elkay sinks seem to be high quality and made in the USA, so for kitchen and laundry room we went with Elkay stainless sinks. For the kitchen an EFRU311610, which is 16 gauge, has tight corners (low radius in the lingo), center/rear drain placement, 30.5″x16″ at the bottom and 10″ deep. In the laundry room, which has a Durat (like Corian) countertop we went with a PLA19190 drop-in sink, and to keep things simple for that sink used an Elkay faucet, their LK2000CR, which fit with no drama.

For the master shower I thought that use of (somewhat expensive) Schluter system components would save on labor, not sure that really panned out, but the Schluter system stuff is nice and I am a sucker for German engineering. So I did my own (curbless, something we specced early with architect, which was good, because shower floor area had to be dropped, doing that later would have been hard to impossible) shower layout, including a prefabricated bench, and ordered Schluter Kerri-Line linear drain and a solid grate. I also ordered Kerdi prefabricated/sloped shower tray, several shower niches, and some membrane, corners, etc. It was harder to find this stuff online, I think I had the plumber order most of it from a local plumbing supplier.

For the master bath tub I locked on to the idea of getting a Duravit Paiova tub early in the design process. It comes in a bunch of different sizes and configurations, a few of which are available in the USA. The one I wanted was a whirl tub, which of course was a discontinued model in the US. But I lucked into finding one, must have been a leftover, it was steeply discounted and must have been sitting in a warehouse for awhile, I grabbed it and it works great, and it has both water and air jets.

Duravit Paiova Whirltub (model 710268)

For the guest bath shower/tub we were working with a bathroom that was 6′ wide (before sheet rock and tile). Seems like a lot of tubs are 5′, but I managed to find one that was 66″ long, had a nice sloped back for relaxing, and a good size tub bottom so not treacherous to use for a shower, also nicely with a tile flange, and like the Duravit acrylic. An Americh Kent 6632, which was also available with jets and other, but for the guest bath kept it simple and just ordered the tub from a local supplier.

Plumber wanted to set tubs right away so he could get working on drain plumbing, but I pushed back and insisted that radiant tubing be installed under the tub locations, than 1/4″ cement board on top of that, then the tunes were set. I should have done a better job protecting them during construction, with blue sticky film, next time.

For plumbing fixtures we wanted something clean looking and wanted to use wall mounted faucets in the bathroom for (a) the clean look, (b) ease of cleaning, and (c) increased vanity top space. Not surprise but the product line we liked the best was from a German company, Hansgrohe, the Axor Citterio M line. Smooth, simple, modern lines. Weird there is not really much out there that compares to this, a lot of the other modern stuff has a lot of sharp angles, not my taste. So I cobbled together the pieces we needed, ordering fixtures and roughs from supply.com and even picking stuff up on eBay and Amazon (everything in brushed nickel). Showerheads I have loved Speakmans since my college locker room days, so we went with Speakman Icon S-2252 shower heads in brushed nickel. These shower heads provide really good flow and coverage and I don’t think I even pulled the (2.5gpm) restrictor out. We put the rough at 85″ above the shower floor, with a 6″ Hansgrohe Shower Arm the shower head is at about 6’7″, so tall people should not need to duck. Rainhead is a Hansgrohe Raindance 300 on a 12″ Grohe arm.

Master bath shower rough in process, note dropped floor for curbless shower
Master bath shower, thermostatic mixer plus 3 valves for showerhead, rainhead, and handheld

For the kitchen faucet we went with a Hansgrohe Axor Citterio in stainless. We wanted something with a spray head, but don’t really like the spearheads that pull out of the faucet. This is a cool look and a little simpler.

The connection to the water main was 1″ copper and we opted for a 3/4″ meter over the standard 5/8″ meter, a little more expensive, including recurring cost, but wanted to make sure we have plenty of water pressure. Most of the plumbing rough was with Plex tubing, color coded, red for hot, blue for cold, and brown for hot-water circulation loops. Speaking of hot-water circulation loops, plumber put in two of those (I think), one to the kitchen, and second to the master bath. I think these loops can be an energy-waster, and to increase the efficiency the plumber installed a Taco SmartPlus circulator, which monitors hot water use and only circulates at times when there is normally demand. We went through a green certification process, and I think this was required for us to get the certificate we got (more on that in another post).

Also worth noting that the plumber used a cast iron drop/waste line for the upstairs bathroom, which line comes down in the wall separating the powder room from the front entrance. PVC drops can apparently be noisy, so it is good to use cast iron where the noise could be noticeable.

Electrical Planning and Rough-In

With the house mostly dried-in (there are still leaks that persist to this day) it was time to get going on rough-ins. The Turkel purchase order identified MEP (mechanical, electrical, & plumbing) as a potential consultant add-on, but not sure we found anyone that we thought could do a good design job across these three very different areas without adding a lot to the project cost. So after discussing with the construction manager we committed to a design-build approach, so the MEP subcontractors “designed” and built.

For electrical, an initial design decision that we made was how we wanted to handle lighting control, with the choice being between a central “brain” with loads all wired to that brain, I guess you would call that home run load wiring, with low voltage and/or wireless to keypads, vs a more distributed system with conventional high-voltage wiring and probably wireless for doing anything fancy with controls. Our prior home had a Vantage system with low-voltage wiring to keypads and it was a little buggy and I think at least two dimmer modules/power supplies failed and were expensive and time consuming to replace. Programming was also proprietary, they make it difficult or impossible for end users to make programming changes so you are handcuffed to a contractor if you want to do anything.

That said, I reached out to a local building systems design/integration/build shop to get a proposal for a lighting control system. I think I was probably also already thinking Lutron, so no surprise that their proposal was for a Lutron Homeworks QS system, $33k for lighting plan and system and nice keypads, with that cost not including line voltage wiring. Seemed like a lot of money for just lighting control for a 2500 square foot 3BR/2BA house, and same problem with Vantage with software only made available to integrators. My wife is also, very reasonably, big on technology layer going on top of conventional systems, rather than replacing, so if the technology fails you are still in business. So I planned to have the electrician do a normal rough-in and then use Lutron RadioRA2 switch gear/controls. At the time RA2 Select did not exist, so I did Lutron’s online training to get access to the programming software. During the build Lutron came out with RA2 Select, which for our application did everything I wanted the lighting system to be able to do (remote control, scenes, and schedules) with more simplicity (100 devices was not a limitation for us given home size), so the RadioRA2 training was a waste of time. I think I added up the cost of the RadioRA2 switches and hubs we would need and it was maybe $7k or so.

I do wonder if my cost evaluation of Homeworks was fair, I never asked the electrician if home run wiring of loads would be cheaper than conventional wiring. But if cheaper it is probably not a lot cheaper.

We planned to do mostly recessed (LED) lighting and I went a little nuts looking at all of the different options, easy to find fancy small apurture LED lights for $400+ per light. Glad we did not go down that expensive path, electrician recommended we use regular 4″ airtight housings/cans (I think they were Junos), lots of options for trims, with Par20 LED bulbs. Our last house had 6″ cans with Par30 bulbs, which is a little large/retro, the 4″ trims fit nicely with the modern aesthetic.

4″ Recessed Lighting Housings

We were a little concerned about the coolness of LED lighting, but the electrician brought over some bulbs to show us options and we were happy with 2700K LED bulbs. He installed (dimmable) TCP 2700K Par20 LED bulbs throughout, 110% beam angle and estimated life of 25,000 hours. At this point (early 2022) we have been in the home over three years and we have not had a single bulb fail yet. We did have some problems with dimming/flickering in one of the bedrooms, electrician immediately knew it was a bulb/AHCI issue and changed bulbs out for a different brand, problem solved.

Speaking of AHCI breakers, we lucked out and got our building permit right before code changed from only requiring AHCI breakers in bedrooms to pretty much all interior areas. AHCI breakers can be finicky, and they are a lot more expensive than regular circuit breakers.

The architect did quick electrical plans with minimal input from us (just go with recessed lighting everywhere) and these plans were used for permitting. Later I made my own lighting/switching layouts, and these were tweaked by walking around and discussing with the electrician.

Main level lighting layout

We did stick with recessed lighting in almost all of the living areas, only exceptions to this being:

  • Pendant for the dining room (Poulsen PH 5, in hindsight probably should have put two of these in, dining room table is 2.4 meters long)
  • Surface mounted foyer light (purchased locally, 9′ ceiling height and didn’t want pendant hanging down)
  • Stair step lighting mounted low on stairs for safety/visibility (WAC WL-LED310)
  • Surface mounted area lighting for enclosed stairs to lower garage/storage level (Tech Lighting Cirque, small size)
  • Surface/ceiling mount lights in walk-in closets (WAC GLO LED, small size)

For electrical outlets I did a walk through with the electrician and we decided where to put electrical outlets. He raised the idea of putting them in the baseboards, but plan was for Fry Reglet trims to create a baseboard reveal (more on that elsewhere) and that would have complicated, so we just went with standard height outlets throughout, tops of the boxes are just under 16″ above the floor.

Additional electrical roughs included:

  • Kitchen appliances, for that our kitchen design had already been completed and we had already picked out appliances (including induction cooktop, which required a 50amp 240 volt circuit), so we were able to pretty accurately place the wire roughs
  • Gas fireplace
  • Ceiling fan
  • Smoke/CO detectors (bit of a sing and dance on these, local electrical inspector and security system installer both said Nest Protects did not meet code due to lack of wired interconnect, I had to get a letter from the State Building Inspector to get the local inspector to sign off)
  • Bathroom exhaust fans (Panasonic)
  • Bathroom mirrors/lights
  • Washer/(gas) dryer
  • Boiler and HVAC (for latter, heat pumps, a sub-panel for the condensers, plus wiring for air handlers and split units)
  • Master bedroom whirl/air tub
  • Doorbell (which I should have done, Ethernet more important than a few low voltage wires)
  • Exterior floodlights (should have done more with exterior accent and yard lighting)
  • Line voltage wiring to digital speaker locations
  • 60 amp circuit to garage area for EV charging, plus an 8/3 to bring 30 amps into the mechanical room for a generator (or send 30 amps to something else in the garage area)

Service was 200 amp underground from pole to panel, some large loads in the home but hard to justify 400 amp service (and local utility might have pushed back).

Finally a word on lightning/surge protection. We skipped lightning rods, I don’t like the idea of “inviting” lightning to find ground through a wire in my house that is anything less than ginormous. But we did do some things to protect ourselves from power surges, installing a Type 1 device at the meter (a Leviton 50240-MSA, which can only clamp up to 50kA, so not going to stop a direct lightning hit, but 50 kA is something …) to deal with surges coming from outside the home, and at our main panel we have a Eaton Type 2 device at the main panel, I think idea of that is to deal with surges caused inside the home, and I suppose also anything that makes it past the Type 1 device. We have some Type 3 devices for computers via UPS devices and some power strips around, but with the whole home protection I passed on surge protection options provided by the HVAC subcontractor, etc.

Main and sub panels in the mechanical room, lots of circuit breakers!

Fiber Cement and High-Pressure Laminate Siding Selection and (Rain-Screen) Installation

A major theme with our selection of materials and finishes was picking things that would be low or no maintenance, we felt this was especially important given waterfront exposure of the home. Early on we latched on to the idea of using a fiber-cement cladding called Cembonit (now called Cembrit Patina Original, Cembrit is a Danish company, no big surprise there, if you like modern things a lot of them come from Europe), which is through colored, pretty much maintenance free, has a nice modern look, and has some character, the surface has some grain and will weather a bit. The cost also seemed reasonable, at something a little over $7psf for the panels, though what I did not appreciate at the time was that fabrication and installation would be multiples of that. My better half was a little concerned about the house looking like a BMW dealership with this siding, but we looked at lots of photos and followed through on the initial idea. Initially we did look at a Spanish product called Prodema, a very nice phenolic that looks like wood, but we were warned it was expensive. Also some Meteon products, we were told those were expensive. For fiber cement I don’t think anyone in the US makes panels. JamesHardie makes fiber cement siding, but only for more conventional shingle and lapped applications. Silbonit (Italy) Equitone (Germany/Belgium), and SwissPearl all make nice fiber cement panels, I think Silbonit was similar cost to Cembrit and Equitone and SwissPearl were a bit more expensive (but again as I learned the material cost is not the major driver of this type of siding installation). We like the Cembonit Pearl color, kind of a creamy off-white (closest Benjamin Moore paint color to this was Soft Chamois, which we ended up using for most of the interior of the house, and also the exterior soffits). Eastern Architectural Products is the distributor for Cembrit in our area and they were helpful as we were looking at different options, another reason we went with Cembonit.

For the lower level our plan was to enclose the garage and storage area with Kynar coated corrugated aluminum (breakaway walls as we were in a flood zone), and we had the idea to bring this corrugated aluminum up over a corner of the main level to break things up. As we were getting the fascia up (Azek cypress color) and thinking about wood decking we came up with the idea of wrapping a corner of the house with Trespa Pura in their Romantic Walnut color. We floated this idea to Turkel and they thought it would work OK (some concern about having too many colors, but everyone got over that). At the time we got the Cembonit I think it came with a 25 year warranty, while the Trespa Pura was 10 years (including color stability).

For the rain-screen we had to choose something to use for furring. Because we initially thought about bringing corrugated aluminum up around a portion of the main level the architect specced 1.5″ furring strips (and brought windows out accordingly), but that seemed like a crazy large gap to me. We could have used aluminum or steel profiles and riveted the siding to those, but it did not seem like any of the subs had ever done that before and degree of difficulty may have been high. For that matter none of the subs had ever done fiber cement panels with reveals before either, we had lots of subs doing things for the first time with this house. Anyway, we figured we should keep it as simple as possible and go with wood furring strips and stainless screw fastenings (heads pre-painted to match the panels). We were planning to use Boral for some trim and thought about that for furring (it would never rot), but the distributor told us it was not suitable for “structural” applications like this. Our construction manager talked us into using primed mahogany furring strips, which cost a small fortune but are probably not going to be prone to rot. We used 5/4x4s most places, and 5/4x6s where panels met. So a 1″ air gap for the rain screen. The contractor who put the furring strips up, with long stainless screws, managed to miss the wall stubs in many places (in their defense maybe the wrap made it more difficult to see where the studs were), requiring some rework and leaving us with a bunch of holes in the wrap.

The final plan elevations included a guess at a siding panel layout, but that layout needed to be updated based on actual panel dimensions to balance efficiency and aesthetics (for latter having reveals line up with windows, etc.). I did the layout by hand using the plan elevations printed out on Arch D (242×36) paper. Initially I used the full panel size where possible, but Eastern Architectural Products suggested using all 1250x2500mm panels (49.2×98.4 inches), but a max size of 48.5×98, which as the tolerance for the full size panels is 1/8″ (3mm), and during fabrication they could trim everything down so things would be spot on. My layout was then the guide for placing the furring strips, which were placed such that fixing would be no more than 24″ horizontally (fastening spec is 16-24″ horizontally and vertically, and at least 1″ from the edge horizontally, and 2.75″ from the edge vertically).

Cembonit panel layout, north elevation

Given that the idea of a rain-screen is that air can circulate behind the cladding I thought completely blocking off horizontal air flow was a bad idea, so I routed 1/4″ grooves every 6″ in all of the furring strips, groove side of the strips to be attached to the studs behind the sheathing. The black RevealShield SA wrap hid sheathing fasteners and the subcontractor putting the furring strips up missed the studs in a number of places, poking extra holes in the WRB and requiring rework (as with most of the quality control issues that arose during this project my construction manager did not catch this early on or at all, if I hadn’t caught it we probably would have ended up with some of the siding supported by OSB instead of framing). If I had a redo I might have had the crew applying the WRB mark the stud locations on the outside of the WRB.

Primed mahogany furring strips with 1/4″ grooves for horizontal air flow routed on sheathing side of strips

The cost of having Eastern Architectural Products pre-cut and pre-drill the panels was nominal, and seemed like a much better option than having the sub that was going to install the panels cut and drill on site, which would have taken forever, cutting fiber cement panels is slow, creates a huge amount of dust, and dulls carbide/diamond blades and bits quickly. But to have the panels pre-cut and pre-drill required accurate field measurements, which I made. I spent a lot of time in a scissor lift measuring and remeasuring, and the final cut sheet was quite something. The lead time on the fabrication was 2+ weeks. We ordered a few extra panels (at $225 per) to allow for some breakage and unforeseen situations where we would need to fabricate on site.

A few takeaways on the installation of the panels:

1. We had a lot of breakage and ended up having to get a few more panels shipped to us (there were a couple of panels that were pre-drilled incorrectly, the supplier took care of us on this and we were able to just add some panels to the order). The 120-odd panels all had numbered stickers on them making identification straight forward, but at least initially panels were offloaded from the truck without recording which panels were in which pile, so there was lots of moving panels around to find the one that was going up next. It was also hard keeping contractors from stepping on the stacks of panels, several were broken because people stepped on them. Finally as they were moving and organizing panels they were often propped against lower level framing, crew left at the end of the day, wind came up in the night, and panels blew over, resulting in breakage. I was constantly laying panels down at the end of the day to try to keep this from happening.

Panels waiting to be stepped on and broken. We eventually placed orange cones to try to keep people from stepping on the stacks of panels.
Panels waiting to be blown over. Crew eventually put plywood up to help reduce this kind of breakage, but depending on the wind direction that often didn’t help much.

2. Putting this stuff up was a very slow and exacting process, and there were several unanticipated snags. I mentioned incorrectly pre-drilled panels, that was one snag. Another snag was a modern home construction thing where sloppy construction quickly snowballs into increased cost. For example, one day I got a call while I was at the office as the siding crew discovered windows on each side of a corner of the house were not aligned, the bottom sills were offset by about an inch. With normal siding no problem. But here we have panels with reveals, and reveals lined up with window edges. So choice here was to have reveal not be lined up with the edge of some windows, or have reveals not line up at the corner of the house. We chose the latter, which I believe to be less noticeable. I think I might have taken the upper panel height from the higher window and carried that height around the corner, so in addition to the reveal miss at the corner we have to cut new (taller) panels to go next to the lower windows. As this material was going up we also discovered that the exterior walls of the home (interior ones too …) were not very straight. The Cembonit panels can flex some, but in some places it would have looked goofy if we did not shim to create a flatter plane for the mounting of the panels.

Hard to tell here, but the upper window to the left is about an inch lower than the upper window around the corner to the right (tight to the eave).
Easier to see the reveal mismatch from this angle, see the top horizontal reveal.
Furring strips not so fair. Also you can see the Coravent at the bottom of the furring strips to keep (large) bugs and critters out, mentioned below.

3. Adding to the time and cost of the siding was the installation of bug/animal screening. I don’t remember who suggested it, but we used Coravent S400 at the bottom of the lowermost panels. I thought we were also going to use it behind the horizontal reveals, but we didn’t and those (8mm) reveals are open. 2+ years in and I don’t think anything is living behind the siding. Also, another step required before siding went up was the installation of EPDM strips, these are available in 100mm width for wider furring strips where there will be a joint, and in 50mm (I think we just ordered all 100mm and cut in half for the 50mm), and must be fastened to furring strips before panels are screwed on.

The Trespa Pura was quite a bit more expensive than the Cembonit, almost $12psf, but was quite a bit easier to put up, so after labor I am not sure that it is not cheaper siding. Planks are 7″ wide by 10′ long and are easy to handle and cut. Color matched screws are available, as well as aluminum edge and corner trims. You screw the bottom plank on, then the planks above are notched and sit on top of the plank below, with hidden fasteners as you work your way up the wall. I put some of this up by myself, it was that easy.

Trespa Pura (and also Cembonit) mostly installed. We used a scissor lift instead of scaffolding for most of the exterior work. It was tight and sometimes muddy at the sides of the home, but worked pretty well.

House Wrap for Rain Screen – Water Resistive and Air Barrier (WRB & AB)

The sheathing that was used for the prefabricated well panels was 7/16″ ZIP System panels. In a do-over I think we would stick with plywood for sheathing and happy a WRB over the sheathing. We ended up adding a WRB over the ZIP panels for three reasons:

  1. With ZIP panels we had a reverse-lap at roof/sheathing joints, and with that not surprisingly water leaking into the house.
  2. Many of the ZIP panel fasteners (nails) were overdriven, creating hundreds or thousands of holes in the WRB. The prefabricated panels were also assembled in Canada, loaded on a truck and trucked to Connecticut, unloaded, moved around, moved around again, hauled into place, and assembled. During that process some of the sheathing got pretty beat up.
  3. We planned to install rainscreen cladding with reveals, and did not want to have green sheathing visible behind the reveals, and the ZIP panels are also not rated for long-term UV exposure, I think your warranty is probably invalidated if you leave them exposed for more than 180 days.

The two main products we looked at for the re-wrap were Dorkin’s Delta-Fassade S (which was carried by Eastern Architectural Products, where we got most of our siding) and VaproShield’s RevealShield SA, which is what we ultimately went with and which we got through Cement Board Fabricators. Both of these products are designed specifically for rain screen applications where there are reveals, being black and UV stable. Also quite high performance, the RevealShield for example has a very high drying capacity (much higher than the membrane on the ZIP panels). Though I am not sure I totally understand the need for breathability, I guess maybe you want it to let the house dry out from when it was open to the elements, but as soon as you install closed cell insulation on the interior I don’t think the house is breathing any more.

The RevealShield comes in 5′ rolls with an integrated tape designed for a conventional horizontal application, and 5′ rolls with the fully self-adhered for which a vertical application is suggested, and which I thought would be a little easier for the crew (our roofers ended up putting it up for us) to install (the SA adds cost to what is already a pretty expensive WRB product). There is also VaproShield tape available that is UV resistant, and does not have the annoying white lettering on it that the ZIP tape has. I was a little concerned about having two WRBs on the house, but called Huber’s technical support and they said it was not uncommon and OK to add a WRB over the ZIP panels.

ZIP panel sheathing before additional WRB installed
RevealShield SA installed over ZIP sheathing

elevated home water line (heated) enclosure

With the home raised on piers and the lower level neither insulated nor conditioned we had to do something to keep the water line coming up from the slab and into the bottom of the home envelope from freezing. We decided to build a 2×4 framed enclosure from the slab up to the home envelope and had the insulation guys spray it with closed cell foam. Plumber then ran heat tape along the pipe and left us with a plug at a nearby outlet so we could plug it in when/as required. You can get a thermostatically controlled outlet to make this approach a little more elegant.

This approach still left me nervous, so I looked for a way to heat the enclosure, and it was surprisingly hard to find a suitable heater with a thermostat that would do the job. Finally found a German-made heater made by Stego, 950 watts, with a built in thermostat. I ordered it from Galco and I think it took a couple of months to arrive. The thermostat can be set at 32 degF or above.

Water line running from slab into home to the right, 1″ copper to 1″ Pex I think
Water line framed in and insulated with closed cell foam, Densglass sheathing (which we also used for garage ceiling and exterior soffits)
Main water line, Stego enclosure heater to the left, Elk WSV2 electric shut-off valve, feed to sprinkler system on the right, need to build a door for the closet, have a 2″ thick piece of rigid insulation that we stick in the opening for now …

roofing and fascia

As soon as the shell of the home was complete we got moving on getting the roofing completed, in parallel with installation of the windows. There were/are four roof surfaces, the top surface pitched 1″ per 12″, and the other surfaces were all flat with plans calling for tapered foam to bring to 1/4″ per 12″.

The top roof was sufficiently pitched for a metal roof, and given the salt air environment we opted for an aluminum standing seam roof. Our roofing contractor used coil from Englert and we picked Dove Gray for the Kynar coating (I think we used 0.032″ aluminum). At this point we had pretty much settled on using Cembonit (now called Patina) in their pearl color for the siding, with a couple of accent walls in Trespa Pura in their romantic walnut, with lower level and trim (and windows) in a bronze color.

For the flat roof surfaces we looked into monolithic (liquid applied) membranes, which are pretty cool, but cost was 2-3x the cost for EPDM. Liquid membranes we looked at included Soprema Alsan RS and Kemper. Our (local) roofer, who was one of our best subs, said he had some experience with these, but for residential construction I think these are a pretty esoteric choice. Our concern with EPDM, which turned out to be misplaced, was rubber tire smell when the roof got hot, and to a lesser extent longevity/durability. It really did not smell, even when new. There are liquid coatings that can be applied to EPDM to increase reflectivity and longevity, we could still put one of these down at some point.

For roof and overhang fascia the plans called for 1x Azek trim painted (it only comes in flat white color) to match window trim (so for us a dark bronze color). The idea of having to repaint trim was not at all attractive to us, 30-odd feet up in the air. Our goal with all exterior material selections was to pick things that were low or no maintenance. I rebuilt a deck at our last house and used TimberTech full PVC boards and fascia. TimberTech has since been acquired by Azek and their boards are capped, but they still make and sell colored PVC fascia boards that are 0.5″x11.75″x12′. The boards are expensive at a little over $100 per, but the Azek warranty is impressive and the color (we picked cypress) is hanging in there 3 or so years in. The roofing crew put the fascia up and found the rim and outer joists to not be very fair, so there was a lot of shimming to get the fascia to be straight.

There are special colored fasteners for the fascia and also a bit for pre-drilling/countersinking that creates a hole that is a bit larger than the screw to allow for movement (PVC moves a lot with temperature). The crew did not really follow the instructions and fixed the fascia without allowing for movement in many places. So far it is holding up.

Metal roof underlayment complete, fascia starting to go up, lots of shimming …
Aluminum coil for roof in truck, formed into panels on site
Aluminum standing seam installation in process
Tapered foam out on the roof ready for installation, to create 1/4″ in 12″ pitch for water runoff, and extra R as a bonus!

The crew flashed the roof/wall connections with copper, not sure exactly what this does, but I think they knew what they were doing. That said, this joint was problematic in a couple of spots where the EPDM was brought up the side of the Zip system sheathing, creating a reverse lap that for me is a fatal flaw of this approach. More on this in another post, but we had leaking problems at this joint and we ended up wrapping the entire home using VaproShield’s RevealShield SA, making the Zip sheathing sort of a waste of time and money. The Zip panels are also OSB, which for strength is inferior to plywood. Lesson learned, for me plywood sheathing and a high quality wrap/vapor barrier are the way to go.

Leaky roof/wall joint
Roofing complete, EPDM drip edge in same aluminum material and color used for the main roof
Completed home showing the colors we chose, siding is Pearl Cembonit, corner of the main floor is wrapped in Romantic Walnut Trespa Pura, fascia is Azek in Cypress, main roof and EPDM drip edge is Englert Dove Gray, window trim and garage doors and lower level corrugated aluminum is dark bronze, decks are Cumaru with stainless cable rails, exterior stairs galvanized steel

The metal roof can be quite noisy on hot, windy summer days. Not sure if this is because of an installation problem, or if it is just a metal roof thing. But it is loud enough that it is a little annoying. Also if we get a melt and then a freeze you can get some pretty hefty ice slabs that eventually get cut by the seams and then slide off onto the roof below, with a large bang. Given that the roof below is EPDM over rigid foam the makes me worry about getting a puncture, so when these conditions occur I go up to manage the movement of ice from upper to lower roof. I am not sure if there is a better way or not. Our neighbor has some snow guards on his standing seam roof, perhaps we should look into putting some of those up. There are also some little stick on shark fins that supposedly slice the ice into smaller chunks.

window configuration, selection, and installation

As we went through the process of developing the construction drawings with Turkel we made some changes to window sizes and locations to (a) improve potential airflow through the home, (b) improve privacy, and (c) accommodate limitations of another product line we decided to include in the package. Once the windows were on site and they started to go in we learned about implications of some decisions we had made without knowing we had made the decisions.

In the initial design all three bedrooms had operating windows on only one wall (the master had a tall/skinny window around the corner of the main wall of windows). That did not make sense to us, and the next iteration had two windows either side and adjacent to a corner of one bedroom. The discussion with Turkel was about airflow you get when you blow on a straw while you have your thumb over the other end of the straw. So we added some operating windows and tried to get them on opposite sides of the rooms.

The home is on the water and SSE facing, and most of the south and east sides of the home are glass. The prevailing breeze in the summer is SW, and initially there was no nice way to open up the north side of the home without propping the front door open. So we added some windows to the north side, including a large operating casement adjacent to the front door (more on the front door in another post). We also added a high window to the powder room, over the commode in the master (giving windows on two walls of the master bath, up high for privacy, but adding natural light and operable for airflow), and a couple of small high windows in the mechanical room.

The Marvin Ultimate window package was not an insignificant cost that was not broken out in the Turkel purchase order, and we tried to get some visibility into that cost as we looked at making changes to the window package. This process was slow and difficult, so we started talking to other suppliers to try to get some cost granularity. During those efforts a couple of suppliers suggested that (Marvin) Integrity windows might outperform Marvin Ultimates and also save some money. Ultrex windows are strong, resulting in small rails and so larger openings, and are not susceptible to corrosion, so ideal for water front homes. Turkel had limited experience with this line of windows and it was a process to bring them up to speed of what was possible and what was not possible. Fixed Integrity casements are available in sizes up to 49 sqft, which is about as large a window as I’d want to have. The size of Integrity awnings is limited compared to Ultimates, so under large windows we doubled up Integrity awnings (so more smaller operable windows, which was fine with us and has worked well in practice), and for large awnings and a multi-slide assembly we stayed with Marvin Ultimates. The Integrity were available with wood on the interior, as well as Ultrex (we used the latter for bathrooms and laundry and mechanical rooms). All windows were available with square sticking and the exterior bronze color of Ultimate and Integrity windows is VERY close. I think more factory mulling gets done with the Ultimate windows, for our Integrity windows steel was installed for at least some of the mulling (maybe partially negating some of the cost savings, but again in a salt air environment I think I pick Ultrex over Kynar coated aluminum). The Marvin Ultimate hardware is a little nicer than the Integrity, but the Integrity is still quite OK and you would not really notice much of a difference unless it was side by side. The awning control handles are both metal, but on the Integrity the locking levers look like they are metal but they are plastic (on the all Ultrex they are white plastic).

Largest window in the house on right in master suite, pretty close to 7’x7′, steel bar to mull upper units to lower awning assemblies
1″ steel plates used for mulling, awnings below large fixed casements for airflow
Full Ultrex Integrity windows in guest bath
Wood/Ultrex Integrity windows and door
Multi slide assembly
Two Marvin Ultimate awnings on the left, Integrity fixed casements/polygons to the right
Integrity on the left, Marvin Ultimate on the right, bronze colors quite a close match

On the stuff we learned about after the windows were on site, that was around jamb extensions and how the window frames were placed in the rough openings. Here is where we started to learn how finishing details could have huge cost implications. For the interior window to wall transitions the plans called for two pieces of trim, one of which was dadoed with the drywall going into the dado. Clearly a ton of work and our construction manager was puzzled by the design. If we were going to bring a jamb extension past the drywall I did not understand why we did not just have jamb extensions built into the windows by Marvin, then bring the drywall up pretty tight and use tear away beads to finish, that would have been a lot less work. The typical finish would be to install a jamb extension bringing the jamb flush with the drywall and then banging some casing around the window. None of these approaches seemed to be very clean to me, clean and minimal was a core tenet of the whole project. So we ended up using drywall for the “jamb extension,” using a tear away bead for finishing at the window jamb and a corner bead at the drywall to drywall corner (much as you would handle the outside corner of a wall). Still a lot of work (and cost), but a much cleaner look.

Window to wall transitions
Drywall jamb extensions, tear away beads at window jambs, corner beads at wall corners

After the windows were in we learned about the importance of how those are placed in the rough openings. The plans called for 1×3 furring of all exterior soffits and interior ceilings. Our construction manager thought it was a waste of time and money to add furring to all of the joists for the ceilings, and installing furring on all of the (pretty extensive) soffits was not going to be cheap. If you did one and not the other the interior to exterior transitions at the windows would have a 3/4″ step from the side with furring to the side without. We decided to skip the furring and deal with gaps that might require trim on the exterior.

During the development of the construction drawings we had been discussing cladding options. On the lower level our thought was to have corrugated break-away aluminum panels between the concrete piers, and we had the idea to bring this aluminum up at a corner of the house to provide an accent to the main cladding (Cembonit cement board panels, more on that in another post). What I did not realize was that as a result of floating the idea of the corrugated aluminum we signed up for 2×4 furring for the cement board rain screen siding. So windows were installed with frames sticking 1.5″ out from the sheathing, so they would be flush. We ended up skipping the idea of the accent corrugated aluminum, instead using Trespa, which would install much as the cement board panels. A 1.5″ rain screen gap seemed crazy to me, though it might have been nice for bird nests. We went with 1x furring, so our window frames project 0.75″ beyond the cladding. Not the end of the world, still looks OK, but during the development of construction drawings I think it would be good if architects highlighted choices being made that have major cost and/or aesthetic implications.

Window frames about 0.75″ proud to siding

Also not sure who picked out the trim for covering the mulls, it wasn’t us, I probably would have picked flat/plain trim. This is what came with the windows, maybe it was a standard/default thing. One of those things that I realized when it was ready to go on and there were bigger battles to fight …

Mull joint trim

package assembly (framing and sheathing)

With the main steel beams in place the package was assembled. Beams, headers, rim joists, and joists (mix of Versa-Lams and Tri-Force trusses and Nordic I-joists) were largely maybe already cut to size, but I think there was some trimming, and lots of that for blocking.

Main level floor system, note extra joists under location of kitchen island
Main level subfloor (Warmboard S) in process

Wall panels were documented in an elevation document that had dimensions to 1/16″. TekkHaus provided detailed placement plans and there was a 3D model of the entire home that could be rotated and sectioned to see exactly what went where (which did not keep some things from going in the wrong place initially, but was very useful for quality control and figuring things out). Wall sections used mostly standard structural lumber and sheathing was 1/2″ Zip System (5/8″ Zip System was used for roof surfaces). A few taller panels had to be redone and those came back with LVLs.

Exterior and most of the interior walls were on 2×6 plates. On the interior walls, we had 2×6 plates for wet walls and also walls where we wanted to have sound deadening (staggered 2×4 studs on 2×6 plates). 2×6 plates were also used on a few interior walls where we really didn’t need them, and we tore some of them out and replaced with 2×4 plates (for another 3″ of kitchen counter space, for example).

Wall panels ready for installation
Main floor walls and interior partitioning complete
Second story floor and roof systems mostly complete
Subfloor and roof sheathing going down on second level
Second level walls and partitioning going up
Upper level exterior wall

The main living area roof and the loft were supported by four 5 1/2″ x 18″ architectural glulam beams, two of which ended up being decorative due to the steel the structural engineer drew into the plans

Upper roof systems going on, glulams going in over main living area
Sheathing complete

In addition to the steel moment frames there were several shear walls. One of these ended up on the master bedroom side of a wall where I wanted to install in-wall speakers, so we ended up ripping that sheer wall out and putting it on the other side of the wall. So a recommendation, give some thought to the side of the wall you are nailing up the plywood for shear walls. There are some rules about the size of holes you can cut in shear walls (and the holes can’t be very big).

Shear wall that had to be moved to the other side of the wall

The Warmboard-S subfloor is a pretty cool product, and I will go into the radiant floor heating part of the project in more detail in a separate post, but there were a couple of things that could have been done better on the subfloor installation. First and mainly, it is critical that a 1/8″ gap be left between the ends of the panels. A number of our panels we installed tight to each other and while exposed to the weather for 2+ months got soaked and there was upward buckling at several joints, creating high spots that could be felt even after the flooring was installed. Second, make sure the panels are installed with the tubing runs perpendicular to the joists. The panels are beefy at 1 1/8″, but the tubing grooves are at least 1/2″ so you only have 5/8″ left below those. Thirdly, Warmboard provides a very nice set of detailed layout and installation drawings (sample here) with their product, which our assembly crew only loosely followed, resulting in some tubing “turns” being buried under floor plates (and so requiring additional router work for installation) and also creating some larger than desired gaps between tubing runs (I think the Warmboard people try to keep runs no further than 12″ apart).

Powder room layout provided by Warmboard
Powder room subfloor as installed, tubing turns on the left under a wall plate …

Another thing to keep an eye on during package assembly, and it seems like this should go without saying, is making sure that framing and floors are square, level, and plumb. Perfection on this is not necessary or possible, but for new construction it is not unreasonable to expect things to be pretty close. Turkel asked that the foundation level not vary by more than 1/4″, which seems reasonable. Seems like 1/4″ in 10′ is generally accepted new construction maximum for a floor to be considered level. I picked up a Leica Disto 7500i to make site and foundation measurements (this model has a point finder camera feature that makes it easier to see the object you are “shooting” in daylight and/or over longer distances), and as things got going with the package assembly also picked up a Leica Lino L2G for level and plumb checks (and I also ended up using this a lot for installing things).

I did not need a laser level to see that we had a problem with a corner of the house sagging, see the photo below. Floor here is cantilevered over the foundation by a couple of feet, and seems to me the structural design was faulty here. The drawings called out a moment connection, but I don’t think a W (open) beam is much good in torsion. This photo was taken after the entire shell of the home had been assembled, so there was another story above this.

Oops, an inch or so out of level in a couple of feet …

The fix to this was to jack that corner of the house up and weld a supporting bracket from the lower beam to the short beam supporting the cantilever. The issue with this, I think, was that this threw the floor level off for the floor above this floor, the guest bedroom ended up with almost an inch drop from a high spot near the corner of the house that was jacked up to the back of the room (room depth is about 17′), though it was also a little strange that the back of the room, which is cantilevered over the floor below by about 4′) fell off 1/4″ to 3/8″ in just 2-3′. When you stood on the subfloor there it felt like you were standing on a hill. This issue was not addressed or corrected during the package assembly, there was a suggestion that maybe we correct with self-leveling compound, but obviously that would have been problematic with radiant heat tubing and subfloor penetrations and gaps. We ended up doing a bunch of shimming when installing the flooring and also underneath a bathtub along the wall where the floor was low. The floor level issue also created a lot of extra work installing baseboard, more on that in another post, which was done with a Fry Reglet trim leaving a reveal below the drywall.

Support bracket

After the foundation was done I put a construction camera up on the top of the electric meter pole, a Brinno BCC100, which ran on batteries and took photos at a specified interval (I think I used 1 minute) and put them in a time lapse video clip, recording to a SD card that I would retrieve once a month or two. Once the walls went up it became a little hard to see what was going on, but the time lapse is kind of fun.

Time lapse of package assembly

structural steel

About a month after the foundation piers were poured the package started to show up on site. TekkHaus provided the steel components, which were stamped “Made in Canada,” but at least a few of the beams also had “Made in Spain” on them. Longest one was a little over 44′. In addition to the wide flange (W) steel beams the structural design included a number of flitch beams with 1/4″ steel plates and several Versa-Lams. The amount of steel in the home was driven by the fact that there were a lot of large windows and some long roof overhangs (up to 5′ over fairly long lengths).

Main level beams in place
2x nailers fastened to steel W beams
Steel moment frames mostly in (one top beam still to be fastened up on two columns)