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TOPIC: General Discussion

Installing a New Roof Advice

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Hi, I bought an old house I am remodeling. The tin roof is at least 50 years old. All the framing is good. The main body is a 12/12 pitch and the addition on the back is a 3/12. I bought the metal roof package and I'm about to install it. To my surprise, under the old tin is nothing but old lathe boards. There is no vapor barrier and the house doesn't leak. I lived in this house before and now I bought it. So I know there are no leaking issues. There are two 2'x3' gable vents. I think the house is not insulated as I heard a squirrel running across the ceiling before :)I plan on gutting it and fully insulate the walls and ceiling. It use to have wood heat and then gas stove heat. I'm going all electric with a central unit. I think I shouldn't just install the new roof on the old lathe boards. They are rather wide with about 6" spacing in between them. But why doesn't the house leak?? My plans are to deck it with 7/16" OSB and felt it before the install. I plan on installing soffit vents which is solid right now. I would like to eliminate or put smaller gable vents in when I do the siding. Do my plans sound okay? Does the ridge cap serve as a ridge vent if I hold the OSB back a couple inches? Or do they sell a seperate ridge vent? I was going to just leave the closures out on the ridge. Would you use a more modern material than felt as a vapor barrier? I'm trying to get out as cheap as possible. Is it possible to go straight over the lathe boards with felt and eliminate the OSB decking? I've built several homes but I have limited metal roofing experience. I maybe helped on 3 of them. Thanks for any advice.
Ron Mitchell

1/18/2011
Does the roof sweat on the backside right now? This question get asked quite a bit on here in various forms. The basis for attic ventilation is only to control humidity. If you control the migration of humidity from the living space, the necessity for attic ventilation is reduced if not eliminate. Seal up the attic floor, install properly placed soffit venting, cut in a ridge vent, and you can eliminate the gable vents. The existing decking boards should be fine but I would like to see some synthetic underlayment over them between the roof and the old decking boards. There are no real issues with the fact that they are 6" apart if they are workable with the spacing of the roof. Eric Novotny
Eric Novotny
An informed customer is the Best Customer!

1/19/2011