I am new to the forum and seek sage advice. We do small remodeling jobs and home repair. I am starting a job where we are adding 5-V galvanized roofing over a lean-to carport that has an old roll roofing surface over plywood. It has experienced some leaks and there is some softness in the decking but the rafters seem sound. Snow load does not present much of a problem and I feel that there is plenty of strength left. I intend to strap it with PT 1X4’s, 2 ft on center attached with either ring-shank gal. coil nails or 2.5″ ceramic coated deck screws. I plan to use the hex head roofing screws with metal and neoprene washers. My question is whether to screw into the ridges or valleys. I get conflicting advice from two of my local sources. It seems that the ridges make more sense especially if a screw were to lose a little grip over time. The structure it is attached to is a two story garage where the owner has nailed the same type roofing directly over the same type roll roofing and he has many nails that have gone their merry way over the side. Thanks for your help ! |
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RASCONC,
30# felt first then gun nail 1x or 2x (non PT) into rafters.Nail eave trim over first purlin and screw rake trim on top of 5-v on sides. Screw on the flat next to the ridges. Set bottom of 5-v to stringline. Double washer rake trim.
KK
Thanks for the info. Why not use pressure treated? Our lumber yard normally has spruce in non treated and yellow pine in PT. I thought that the pine would give a better hold and if there was any water contact it would do better. The price is actually less for the PT here.
What is the reason to screw in the flat other than the obvious fit to the roofing? It seems that the double V does not pull down very well when using the flat. It is great to get your advice. I am not questioning you judgement, just trying to understand so I can tell my customer why I am doing it differently from the way he did the main building.
Thanks again!
Edited 10/7/2002 10:16:29 PM ET by RASCONC
There is some concern that the CCA will cause galvanic action with the metal. You really don't want the lap to be tight as it provides a capillary break. The side with the "foot" gets lapped. Don't use acid cure silicone as it will eat holes.
KK
Go for standing seam!! It is not hard to do yourself on a little job, and by God! It will probably last >50 years.
I always screw in the ridges. I figure the roof has more give to it that way, as the metal and wood expand and contract.
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