I have a Cape in CT that has a 12/12 pitch front and a 2/12 rear roof and am having it re-roofed due to old shingles in front and leaking ones in the back. Plan is to use shingles in front andc Polyglass in back. I have cathedral ceilings with R19 insulation and no ventilation. I want to have vents installed(soffit, baffles on top of insulation, and ridge vent) but worry about reducing already thin insulation. Is it worth the $ and loss of insulation thickness to get the venting? Not yet sure if I have mold- will find out when we open it up…
I install the Smart Vent from DCI Products on all of the cape cods that we do, with Shingle Vent II for the Ridge Vent and install an extra internal baffle when the opposing pitch is very shallow.
You need to check the inside first to determine the mold possibility.
Also, by installing the Intake Venting from the roof decking, under the shingles instead from in the soffits, you get the full 9 square inches per lineal foot and the insulation does not lay on top of the soffit vent holes, but you still have to ensure that there is an air path for flowage.
DOnt forget to add baffles from the smart vent all the way to the ridge. WIthout it if the insulation is packed to the roof deck not will ventilate it without them. And that includes tearing all the wood off and replacing or reapplying it.
How long did this roof last?
In a cape cod style house they ussually have gable vents.