Spray Foam Inspection & Testing in Crawlspace and Side Attic

From 'Home Diagnosis' Season 2 Ep6: Spray foam insulation is often advertised as a cure-all, but there are LOTS of ways to mess it up. Here's a tour and testing of a home in Atlanta where the spray foam insulation isn't doing what it was intended to do. Watch the whole episode: https://homediagnosis.tv/episode-206-windbreakers-air-sealing-and-insulation

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Fire Resistant Homes: Testing Vulcan, Silica, and Baffled Intumescent Vents

We found these vents at the International Builders' Show, and were excited to test their performance (partly so that Grace could use her flamethrower). We test the three main types of fire-resistant venting for homes: an intumescent honeycomb vent, a silica vent, and an intumescent baffled vent.

Airflow testing was performed with an airtight box made of plywood and acrylic, using a DU300 fan and DM-32 and DG-8 digital pressure gauges. For the fire, we used a propane weed torch you can get at any hardware store. The chart of our airflow testing shows the square inches of opening inside the metal frames, the airflows, and the pressure drops of all three vents.

For the 'Net Free Vent Area' (NFVA), visit the manufacturers' websites. Brand names of these three vents are Vulcan Vents, Embers Out, and Brandguard. For more on the vents that performed best: https://VulcanVents.com

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Whole House Fan Mythbusting

You know what I don’t like? When people try selling one product across America with pseudoscience or vague claims about benefits in home physics, chemistry, or microbiology. Here’s my rebuke to one specific instance of this kind of over-stated marketing in the world of ‘cooling your house as cheaply as humanly possible’.

How to Fix Summertime Heat on Your Top Floor

Hi Corbett-
Finally, I have two solid quotes for air sealing. I have one new concern, however. My finished attic gets really hot in summer, and the A/C dedicated to this attic rarely is able to cool the space below 82 degrees.  From what I have read, besides implementing some kind of reflective roofing material, the only way to keep an attic cool is plenty of airflow.  So, if we air seal the attic and add insulation (which I have read holds and radiates heat in summer ?), is this air sealing initiative going to make my attic unlivable in the summer?
Thanks!
R.L.

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Hey there R-
First thing to do is stop thinking about your top floor as an attic of any type.  Yes, it used to be an attic, but now it's supposed to be inside the enclosure, so let's call it what it is- your valuable living space.
Not only will airsealing NOT going to make your top floor (finished attic) hotter in summer, it is in fact the ONLY THING that will make it cooler up there.  What's happening is called reverse stack effect: your air conditioners are creating cooler, drier, DENSER air, which sinks to the bottom of the house. All the air conditioning wants to be in the bottom of the house at the same time, so it creates a higher pressure down there, and there's a low pressure at the top of the house.
The cool, heavy air escapes through gaps and cracks in the bottom of the house, and the house now needs air, so it breathes in at the most depressurized (and also hottest) place- at the very top.  So all the air that's in your top floor rooms is coming from the attic spaces and the roof cavity.
Lastly, it's a total myth that attic ventilation will keep an attic cool- #1, attic ventilation is actually for venting MOISTURE, not heat; and #2, you don't actually care how hot it gets in your attic, since it's not part of your house.  The roofing manufacturers used to void their warranties if the attic got too hot, but they don't do that anymore.  You're free!
For a more detailed look at attic airsealing, watch this:

This is NOT a Roof Leak: What Condensation Can Do

Visit an attic (vicariously) with building performance expert Corbett Lunsford to find a tiny problem that may force us to replace the floor and ceiling of this building- and it might happen to you someday too! Stop guessing- Proof Is Possible. Get up in that attic and have a look!