Vented roofs leak, blow away and burn? Lstiburek
mikeolder
| Posted in General Questions on
I was watching a video where Lstiburek says “Vented roofs leak, blow away and burn. Unvented roofs do none of those things. Duh”
https://www.youtube.com/watch?v=R8kz_TN7GiA
I understand why Texas basements, aka attics, need to be unvented and conditioned due to the absence of a basement for mechanical systems. But I’m wondering why, or if he said this about all attics in general?
I live in the north and am considering pouring a basement, mainly for a tornado shelter and second for mechanical systems, but should I consider a unvented roof for performance in Iowa 5A?
Thanks!
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Replies
It makes life simpler. But, no you dont have to. We are in same zone, it'll work either way IF DONE CORRECTLY.
Hi Rerod,
Joe says a lot of snarky things. He may be pointing out potential problems with poorly built unvented roofs, but plenty of high performance architects and builders, when they don't need the attic for mechanicals and their clients aren't asking for cathedral ceilings, insulate the attic floor and vent the roof. And the roofs don't leak water and the houses don't leak air. In fact, many of these houses hit extreme air tightness numbers. When it comes to high wind zones and fire-prone areas, that's a different story. In some locations, those are legitimate consideration. In other areas, not so much.
Build a basement (or equivalent) for tornado safety and buy insurance to cover house damage - you need both no matter what roof design you use.
I find it interesting that Lstiburek recommends mesh reinforced fluid applied exterior air sealing.
Hi,
Just watched the following video and he may mention something about concerns for unvented roofs when they get a lot of snow on them.
Maybe someone can talk to this.
Thanks.
https://www.youtube.com/watch?v=iHBYvqr2_io&t=4445s