Vented vs Unvented Roofs | Midcentury Modern Architecture Design Detail Explained | PPD + PDD

You NEED to know this for the ARE 5.0!
Blog post: www.byoungdesi...
Check out the below resources to dive deeper:
Building Construction Illustrated: amzn.to/3YukOSe
Architecture Details: www.firstinarc...
Join the Mind Over ARE waitlist now to get first access to my next group coaching: www.byoungdesi...
+ ARE Activity Book: dci.byoungdesi...
+ 31 Best ARE Tips FREE download: dci.byoungdesi...
+ ARE Resource Guide FREE download: dci.byoungdesi...
+ Ultimate Study Plan course: dci.byoungdesi...
+ Contract Templates + mini-course: dci.byoungdesi...
linktr.ee/byou...
Find out more about my studio and me here: byoungdesign.com
Find all my recommended products here: kit.co/byoungd...
Check out my freebies here: www.byoungdesi...
If you enjoyed this episode, it's inspired you, or you've found value in it, please let me know on Instagram or KZbin @ByoungDesign.
Don't forget to subscribe for more content like this! You can also leave a review on iTunes (Design Create Inspire) and share your favorite parts with us on Instagram @BYoungDesign.
#architecturestudent #architectureschool #ARE50 #architectregistrationexam #examtips #exammotivation #entrepreneur #womeninstem #womeninarchitecture #futurearchitect #businesstips

[@GoldenBirdBrain]

One of the best explanations of the challenges in balancing insulation with ventilation for roof systems-thank you!

[@BYoungDesign]

Amazing! Thank you. I’m glad it was helpful.

[@percyjen6490]

This details is really good for everyone to know, especially as a homeowner. Thank you

[@BYoungDesign]

I agree! Thanks

[@mykdub7811]

Great information. I have a question. On a mid century home with no attic over the living room what advice or recommendations would you give to reduce heat penetrating flat roof?

[@MykaelaScarpace]

Super helpful! Thanks, Bryn

[@BYoungDesign]

Good! I’m so glad 🙂

[@iamblaineful]

The detailing for unvented roofing systems is pretty straightforward. Handle bulk water, meaning have no leaks. Deal with and eliminate air leakage as much as possible. Understand the 2 reasons you get moisture in unvented cavities and prevent it. Moisture or vapor leads to condensation when a cold surface is exposed a warm environment, just remember that glass of iced tea you have in the summer and the condensation forming on the outside of the glass. A cold roof deck in the winter, that thermal bridging will lead to condensation forming on the underside of a roof deck. The second factor is vapor/humidity which will find its way to the highest points in a house. Breathing, cooking, bathing, etc...all create additional humidity (vapor) that has to be dealt with. You can learn more about this with Matt Risinger on the Build Show on youtube. Vapor Diffusion Ports, Conditioned Attic spaces, etc...

[@sudhareddy5219]

LOVED this video. Question for @byoungdesign: our home (built in 1960) doesn't have an attic, no soffits, and has 3" rigid insulation. We also have clerestory windows that go right up to the roof facia. We also have a skylight and sun tunnel, both of which will be reflashed. We are about to re-roof our house and ventilation is a big topic. Do we need to do anything special to support the health of the shingle and home? For example, do we need raised ridge caps? Should we install permeable underlayment? I believe that the rigid insulation goes right up to the top-layer sheath.

[@BYoungDesign]

Great questions! Your home sounds amazing!! First off, each location is different, so it’s best to double check with a local architect to confirm what your specific climate needs. With that said, it’s possible your roof is unvented OR there is a small air gap that is sufficient for the ventilation. There may be a way for the roofers or someone to check how the existing structure is assembled. If non-vented, take a look at non-vented roof details (check with architect) to see if you need to add any additional insulation or underlayment. If vented, just want to make sure the existing venting is sufficient. Sometimes these midcentury homes have a little venting but not much. Lots of unknowns, so getting a contractor to confirm existing conditions and then confirming with a local architect what the ideal roof system is is your best bet. Hope that helps!

[@sudhareddy5219]

Thanks for your comment! We are in Portland, OR. Also, we confirmed that the roof is not vented; it's a hot roof with 3' rigid insulation so no apparent way to enable airflow but we won't know for sure until the work starts. Our home was actually the personal residence of a local mid-century modern architect from the 60's! The original roof had no insulation and was fully TPO'ed (or some other membrane). I asked similar questions on other roofing forums and the consensus is that a permeable underlayment and ensuring that the roof is airtight will do the job. What's unfortunate (or unfair) is that we don't qualify for the roofing manufacturer's extended warranty b/c the roof is not ventilated. @@BYoungDesign

[@Dee-mp3hz]

Thanks for sharing this information, wondering what your thoughts would be about doing as you mentioned in the end by using rigid foam between the roof deck and truss, and use a butyl tape or equivalent to seal everything water tight. Do you think it would be possible to use a 2" rigid foam with an R10 above the trusses and then fill in with bats in the ceiling, or would there me enough of a thermal transfer/loss for condensation to build up if air from vents and lights were to pass through? Maybe it's unavoidable to just build up the required R value foam thickness above to meet code before creating a penetration in the ceiling. Any thoughts on this would be much appreciated. Thanks

[@computationdesign]

thank u

[@courtneysouthwick5207]

What was the thickness of the facia, and total thickness of the roof?

[@BYoungDesign]

Hey Courtney, thanks for reaching out! I can’t remember the exact dimensions, but if I recall correctly the roof used 2x12 conventional framing.

[@stevejudge3561]

Are you an Architect?

[@BYoungDesign]

Yes