Travis Builds It

The spray foamers didn’t cause this.

In fact, the spray foam work here looks fine.

The problem happened afterward.

This house has a spray-foamed attic over the conditioned part of the house and a traditionally vented attic over the garage. There’s a dividing wall between the two, which means that wall is part of the building enclosure.

Then another trade needed access.

So they cut holes through it to run wiring and data cables.

I understand why they needed access. The problem is that once you cut through the air and thermal boundary, you have to put it back.

Otherwise that vented garage attic is now connected to the encapsulated attic you’re trying to control.

And this is why I actually prefer providing intentional access to spaces like this.

A properly installed FAKRO access door gives future electricians, HVAC techs, data installers and other trades a way to get where they need to go without somebody grabbing a saw and creating their own entrance.

The lesson isn’t “don’t let trades into your attic.”

It’s know where your building enclosure is, and make sure anyone working around it understands that it needs to remain continuous.

Save this if you have a spray-foamed attic. The work done five years after the foam can matter just as much as the foam installation itself.

Window film is one of those upgrades where you can actually feel the difference.

My buddy Joe Carlisle from Vision Home Performance came in from Alabama, so naturally I put him to work at my house. 😂

We’re testing window film as a way to reduce solar heat gain through the glass. Same house. Same afternoon. Two nearby windows.

☀️ Window without film: kept climbing
🪟 Window with film: leveled out
🌡️ During our quick test, we were seeing about a 10°F difference at the glass

And this wasn’t just a thermometer thing. With the AC turned off, I could noticeably feel the difference standing near the two windows.

Bonus: the film also adds some daytime privacy without making the glass look dramatically different from inside.

This is exactly the kind of home-performance solution I like exploring. Don’t just ask, “Does this product work?” Ask what problem are we trying to solve, and can we measure the difference?

Joe and I are going to be doing more testing with this, and we’re working toward bringing window-film solutions like this to homeowners here in DFW.

Save this one if you have rooms that get hammered by afternoon sun.

Build Show Live may be over, but apparently we’re not done talking about it. 😂🍻

Tonight at BS & B**r DFW we recapped the week, swapped a few stories, talked a little building science… and figured we’d send a message to the man responsible for getting a whole bunch of building nerds together in San Antonio.

WHAT’S UP, RISINGER?! 👋😂

Thanks for another great Build Show Live, Matt Risinger.

Now back to our regularly scheduled b**r and building science. 🍻

**r

Powered attic fan cult, I’m just checking in on y’all. 😂

I was doing a pre-purchase inspection for the buyer of this house and found two powered attic fans.

Neither one was working.

When did they stop working? Who knows.

And that’s one of my biggest problems with using powered attic fans as the solution to attic ventilation. You’ve added motors, controls, wiring and moving parts to a system that the homeowner may never think to check again.

When it quits, there’s usually no warning. The roof still looks the same. The fan is still sitting there. It just… isn’t ventilating anything.

And even when powered fans ARE running, I still want to know where their makeup air is coming from and what pressure they’re creating in the attic relative to the house.

Attic ventilation should be designed as a system, not just solved by installing something that spins.

Powered attic fan people, I know you’re here. Defend your beloved machines in the comments. 😂

Part 5: Houston Spray Foam Failures | Your turn to diagnose 👀

I’ve been pointing out the problems in this spray foam retrofit.

This time, you tell me.

There’s a building-envelope problem in this video. If you’ve been following Parts 1–4, you’ve already got a pretty good idea what I’m looking for.

Can you spot it before I pull out the thermal camera?

And if you can see it, don’t just tell me where it is. Tell me what’s wrong and how you’d fix it.

Drop your diagnosis in the comments.

I’ll pin the best answer, or if nobody gets it, I’ll come back in 24 hours and spill the beans. 😂

Part 4: Houston Spray Foam Failures… or is it?

This one is worth discussing.

In a traditional vented attic, we insulate the skylight shaft because the attic is outside the building enclosure.

But what happens when we move the insulation to the roof deck and bring the attic inside?

Technically, the skylight shaft is now surrounded by conditioned attic space. So do we still need to insulate it?

Here’s why I think I would.

The skylight itself is still a significant connection to the outdoors. Many acrylic skylights are designed with drainage paths or weep holes, and that assembly can see a lot of solar heat gain.

The thermal camera made that pretty obvious here. This shaft was hot.

More importantly, I found significant air leakage around the top of the shaft. That absolutely needs to be addressed.

Once we’re fixing the air sealing, I’d go ahead and insulate the shaft walls too. Give that transition between the skylight and conditioned space a little more protection from the heat above.

Is leaving the shaft uninsulated technically a spray foam failure? I’m not convinced I’d call it that.

But air sealing it well is non-negotiable, and insulating it makes sense to me.

Building science people, what are you doing with skylight shafts in an encapsulated attic?

Part 3: Houston Spray Foam Failures

This one is a small detail, but it’s exactly the kind of detail that matters.

The spray foam comes all the way down the roof deck toward the eave. There’s a ceiling joist right there, leaving only a small gap between the joist and the foam.

But that gap still has pe*******ons running through it. A condensate drain line here, wiring in other areas, and pathways for air to move through.

They were so close.

Instead of trying to detail every little pe*******on in a tight, difficult-to-reach space, keep going.

Foam across that remaining gap and down to the drywall. Now you have a much better opportunity to create a continuous air and thermal boundary at that transition.

That’s the lesson here.

Don’t just ask where the insulation is. Ask whether the air barrier actually connects.

Sometimes getting the detail right only takes a little more material and a little more thought.

Save this one if you work with spray foam or conditioned attics.

Part 2: Houston Spray Foam Failures

Before you spray foam an attic, somebody has to answer a pretty basic question:

Where is the building envelope?

Here we have a conditioned spray foam attic that extends over the front patio.

The patio is outside.

So we have two legitimate ways to deal with this transition. We can create a dividing wall and establish the air and thermal boundary there, or continue the enclosure over the patio and properly connect it back to the house.

What we can’t do is stop halfway.

The thermal camera helps us see the temperature difference between the insulated wall and the uninsulated ceiling.

But the bigger concern here is air leakage.

Penetrations. Corners. Transitions. Voids. All the little places where the air boundary was never completed.

This is why spray foam isn’t just about spraying foam on a roof deck.

It’s about understanding the enclosure and making the air and thermal boundaries continuous.

The product can only do its job if the assembly makes sense.

Save this if you’re considering a spray foam attic. Part 3 is coming.

Part 1: Houston Spray Foam Failures

Spray foam at the roof deck changes where we’re defining the building enclosure.

The goal is to bring the attic inside the enclosure. But that only works if the air and thermal boundaries are actually continuous.

This attic had some pretty significant misses.

Around the chimney, areas that should have been separated from the conditioned attic were left open. We could feel significant air movement through those openings.

Then we found sections of roof deck that simply didn’t get foamed, probably because they were difficult to access.

Outside temperature was only in the 80s.

That exposed roof deck? 111°F.

That temperature difference is a pretty good clue, but it doesn’t tell us everything by itself. The bigger issue is that the enclosure isn’t continuous.

Spray foam can be part of a really good attic assembly. But the details matter.

Where is the air boundary?
Where is the thermal boundary?
What belongs inside?
What needs to stay outside?
And did we actually connect all of it?

That’s the building science part.

And Houston gave us plenty more to look at.

Save this one if you’re considering spray foam, because Part 2 is coming.

I learned this one the hard way.

I’m a big fan of the FAKRO Upper Hatch for attic stairs. If the existing ladder is safe and in decent shape, adding an insulated, gasketed upper hatch can be a relatively simple way to improve the air seal at one of the bigger holes between your house and attic.

But don’t just measure the rough opening.

You also need to measure how far the folded ladder extends above the attic floor.

The standard Upper Hatch box is 7 3/4” tall. The extension adds another 4”, giving you 11 3/4” of clearance.

On this one, the folded stair was roughly 9–10” above the attic floor, so the standard hatch alone wouldn’t clear it. The extension solves that.

How do I know this matters?

Because we installed one before, tried to close the stairs…and couldn’t. 😑

Ordered the extension. Came back. Lesson learned.

If your existing attic stairs are still safe and functional, this can be a nice alternative to replacing the entire ladder assembly. It’s also a pretty approachable DIY upgrade for the right homeowner.

Just measure width, length AND height before you order.

Save this one before your next attic project.