Shed-style roof addition to mobile home, roof ventilation/insulation...options?
I've had to pick up on a building addition to the rear of my mother's doublewide trailer where the project had been abandoned by an unscrupulous contractor (absent any written contract...Mom was WAY too trusting).
I intend to apply .060 EPDM atop fiberboard underlayment over a 5/8" OSB roofdeck. The rafters are 2"x8" (roughcut lumber, full 2" thickness) at 16" on center.
At this point in the build, I have just laid down the OSB roofdeck and a layer of 30# felt underlayment (as a temporary protection from the elements while awaiting materials that I can't buy for another week or so)...will install windows and doors in the meantime
My question is this...
Is ventilation even necessary in this instance and, if so,what is my best option to properly vent this roof to be certain Mom isn't stuck with condensation/mold/rot/mildew while still heating/cooling the space efficiently ?
I intended to install R30 kraft faced fiberglass batts in the rafter bays before sheetrocking the ceiling...but that takes all 8" of available rafter height. I worry that installing foam vent spacers between the insulation and the underside of the roofdeck will cut me down to only having space for R19 fiberglass in the rafter bays....and I don't believe that to be adequate ceiling/roof insulation at all.
No way for ridge or gable vents to complement vented soffits with trays above the insulation anyway, as there is no ridge or gable...lol...and I worry about installing any panel vent on this roofdeck because of it's general flatness (pitched at about 2/12)
Any helpful advice from all or any of you more experienced tradesmen here is greatly appreciated...I'm handy and highly adaptable...but I can't even pretend to be an expert :-)
Oh..and, climate is relevant, so...I'm in upstate NY, Adirondack Mountains region...hot summers, deepfreeze winters and MUCH average yearly snowfall...but (bright side) no realistic worries of tornadoes...and no hurricanes to date
Also...budget is EXTREMELY limited on this project...will consider myself fortunate to be able to finance materials bit by bit over the next 2-3 yrs....so I don't think I can swing sprayfoam, financially.
Last edited by Chancemo; 08-23-2011 at 07:17 PM.
Reason: added info.