Low slope roof (2/12) in Colorado w/ridge vent
Appreciate comments from all & Martin Holiday,
I’ve got an old remodel with a T&G roof deck.
Below the T&G will also be SIGA Majrex then drywall. https://www.siga.swiss/us_en/catalog/majrex
On top of the T&G will sit 11 7/8 I-Joist that packed with Fiberglass Insulation. On top of this will be SIGA Majcoat (a one way vapor membrane). https://www.siga.swiss/global_en/catalog/majcoat/majcoat-majcoat-sob
Then a 2-inch air gap (2×4 sleepers) followed by decking and TPO roof.
— See Attached Drawings —
At the ridge line will be a vent
http://www.airvent.com/index.php/products/exhaust-vents/ridge-vents/continuous-ridge-vent#description
I’m concerned about the low slop roof and the possibility of snow build up or wind entraining rain water into the ridge line vent.
Opinions or Comments?
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Replies
MCMB,
Infiltration at the ridge may well pose a problem, but the larger one is that low-slope roofs don't have sufficient pitch to move air through their ventilation channels.
https://www.greenbuildingadvisor.com/article/insulating-low-slope-residential-roofs
You are much better off designing an unvented assembly.