Installing AZEK sheets with PaintPro technology and how some high-performing black paints can reflect heat
In the last episode of Building Resilience, we were doing some weird science that wasn’t really science. We had a technical engineering Zoom conference. Better still, we installed the open-joint cladding system from AZEK.
MA: This is a PVC deck board, which we’re repurposing as a cladding material. And it kind of makes sense because it’s already designed to withstand the elements. It’s designed to be walked on, it’s designed to be beat-up, and we’re putting it in a spot where it’s going to get a lot less weather, a lot less UV, it’s going to get no foot-traffic at all. It should last an incredibly long time.
Another thing that’s going to last an incredibly long time is the ¾-inch AZEK Sheets with PaintPro technology. Because they are PVS, they are virtually rot proof, so they are even being used as a below-grade protection board for the foundation insulation.
MA: The codes require that we install what they call a protection board over the insulation on our foundations. Here in Minnesota, we are putting three inches of insulation on the exterior of our foundations. The insulation comes up out of grade. So, how do we protect the insulation? The code asks us to put some sort of protection board on. They don’t define what it is. They don’t give any specifications. They just say “protection board.”
So we need to find something that’s rated for ground contact, that will keep the insulation safe and will not deteriorate over time, and can withstand rocks and other homeowner type activities.
It turns out, ¾-inch PVC is kind of the perfect product for this. You can see we’ve got it all installed along the foundation here, and it is pretty rock-solid.
It’s rated for ground contact. It’s rated to be buried in the ground. It’s PVC; it doesn’t take on moisture, it won’t rot, it’s there for the life of the house, and keeps it pretty well protected.
I think regardless of building type, this is our first time using it, and I think regardless of the cladding type above, this is going to be our stand-by material. It’s aesthetically pleasing, it’s real easy to install, we know that it’s going to last, we know that it’s going to work.
The code requires that we do something, and I think this is probably it.
Panels and channels define a modern makeover
The edges of the panels are trimmed with architectural channel stock from Tamlyn. They’re called Tamlyn Extreme Trim.
They give the panels a clear definition, allow for slightly imperfect cuts, and give the panels a little room to move during temperature fluctuations.
That all sounds pretty easy, but it is because a lot of difficult thought went into where to place the channel stock in the first place. For that, Michael used windows and other architectural elements of the house along with some basic design rules.
MA: It’s a confluence of the materials and trying to come up with some kind of language for the house. Something that is distinctive style and pulling on existing motifs. For me, this is Minnesota, Frank Lloyd Wright looms large here. His influence is primarily Japanese architecture. I lived in China for a couple of years and Japan for a year, and my aesthetic brings a lot of that in. So, the “two-thirds, one-third” rule is a really big one.
I am trying to avoid symmetry, making it as asymmetrical as possible and achieve balance in that asymmetry.
It’s much more like art than anything else when it gets to this stage. It’s less about problem-solving or engineering, and it’s much more about flow and what that visual language is.
One of those elements is the continuous orange band above the upper windows. It gives the eye a chance to pause and absorb before looking at the rest of the composition.
Precision framing is elemental to precision design details
But while designing the exterior cladding is more like art than engineering, elements like the continuous trim band mean that the technical team needs to be on the same page as the artists.
MA: I think your point, Dan, about the precision that’s required when you do something like this is noted for sure. And I think when you’re shooting for this level of precision, the framing crew has got to be on board with the final design. Once it’s framed and done, the trim guys can’t come along and make it something else. And if the windows don’t line up, those metal trims are going to show you right away if you missed the mark.
The process for installing the Tamlyn trims and the PaintPro panels is you start at the bottom, start at a corner, and move across in one direction. The process we used was really to attack one side of the house at a time. We did the south elevation, then we did the east elevation them we did the north, and then we came around and did the west.
So we were very intentional about how that lays up.
So there’s a process and order. You start on one side, and you move across and up.
The installation of the panels themselves, we’re using the cortex screws, we go through the face of the panels themselves. Behind the PaintPro panels, we have the Slicker Max by Benjamin Obdyke, so we’re not worried about furring strips. We don’t need to land on any particular point.
Our fastening base is that ZIP System R-12, that 7/16-inch OSB. We’re not going back and looking for studs.
That’s huge. The fact that we don’t have to hit furring strips is a little more forgiving in terms of where the screws land.
And because all of the screws are plugged, you can’t see the screws, so we don’t have to go through and mark precisely where the screws go, so when I look at it, I have a perfect vertical line. That’s huge.
Pinning the edges is the most important thing, so it’s a twelve-inch pinning pattern around the perimeter and sixteen in the field.
Why can they use dark blue paint on PVC panels?
The question everyone is asking their screens right now is, “how can you paint PVC panels dark blue like that and not expect them to swell like a buffalo?"
We asked exactly that question to AZEK’s technical experts on a Zoom call.
MA: For the PVC panels, I noticed there is a color guide for paint. And there were some comments about regular latex paint; keep your color render within these parameters. If you’re using a vinyl-specific paint, you get a little more bandwidth, and if you use the AquaSurtech product, which we’re using on this project, the sky’s the limit; you can paint it dark black.
Help me understand how heat and pigment and panel interact. What’s going on there?
David Parker: OK, let’s say you got online and Googled, “When does vinyl siding start to distort?” You start to look at polymers and PVC, and what you’ll find out is that about 140 to 145 degrees F. When the core of any plastic material starters to get over those temperatures, that’s when—that shrinking effect I told you about?—that’s when the steady curve goes down fast. Depending on the maximum temperature, it starts to flatten again. Essentially if the core of the product only sees 120 degrees, the softening curve stays flat.
It could be 200 years, and you’d never see enough shrinkage with the naked eye of the material even though that product is shrinking over time.
The minute you get over the 140-degree mark, that line goes from flat to sharply downward. All plastic manufacturers want a flat line.
So when we talk about the coatings, what we are trying to do is limit the heat build in the core of those products, so they don’t get in excess of 145 degrees.
So that’s what’s behind the special paints and requirements there. It’s all about heat build.
DM: How does the special paint spot the buildup of heat? Does it contain some kind of heat barrier? If it’s a dark paint, does it contain some kind of barrier that’s reflective? How does it stop the heat?
DP: That’s a good question. If we went through our painting requirements, the first one is that we tell customers to look for the LRV (Light Reflective Value) of the colors they choose. As long as that value is above 55, you can use 100% acrylic latex paint.
Essentially, there is enough sunlight reflected off those lighter colors that it doesn’t get to those heat-build temperatures that we don’t want to see.
The next step is vinyl-safe formulas of 100% acrylic latex paint. What that means is they essentially take two pigments out. They take raw umber out, and they take black. Those are obviously the two pigments that produce the greatest amount of heat-build.
So they remove those two pigments and replace them with other pigments to get the same color.
Sherwin Williams has done a phenomenal job on the retail level to provide vinyl safe formulas where they’ve removed those heat-build pigments.
And the last one is AquaSurTech, and they make solar-reflective pigments. They have the ability to make black paint with similar heat-builds to coatings with LRVs of 55 or greater by putting additives in that coating that actually reflect the sunlight away from it, so it doesn’t absorb that heat. Whereas your basic black and raw umber absorbs the heat, those coatings actually reflect it and reflect the sun away.
It’s almost like adding flakes of mirror, which is not what they do, but it’s essentially what they’re doing so they don’t build heat.
Next time: Decking, daydreaming, and a resilience wrap-up
So the AZEK sheets with PaintPro technology wrap up the outside of the “Building Resilience” envelope. All that’s left to do is to heckle Michael as he finishes everything off with an oddly-shaped deck, using the same material for decking that was used as the open-joint cladding, only slightly darker.
We’re also going to walk down memory lane to when we began the project and explore all of the things that made us happy for resilience during the span of this project.
“Looks beautiful, it’s fantastic. It’s fast and dried-in… it’s bomber!” [Steve Schirber, ShelTek, framing contractor]
While the house is built for resilience, the world tested people’s resilience, too, since we broke ground, and we’re going to invite one of our Instagram pals on the show to talk about her personal journey of resilience as a woman of color in the construction world.
MA: ...and also, you’re using Festool. So, not related to resilience, who is it that said, “Hey, you’re new to the trades, you should go out and buy the most expensive, best-performing tools first.”
Rachel Taylor: The short story is that I did a lot of research, and a friend of mine was also doing a lot of research. And he watched all these videos. I, on the other hand, had four kids to raise. I’m very good at asking people, “What’s the best?” and you get told what’s the best.
In carpentry, the best equal time management, and I did know that. I feel like when you buy crappy tools, they are frustrating. You can’t really learn on a crappy tool… because it’s not calibrated, and you’re not going to get a 90-degree cut. People don’t always understand that that 90-degree cut makes—or an 87-degree cut on all corners makes a pretty interesting-looking box. And pretty much all furniture is, you know, an amalgam of boxes.
In the meantime, stay tuned, and stay resilient.
You can see all episodes of Building Resilience here.