1/2" vs 5/8" roof sheathing

Old 12-28-04, 07:50 PM
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1/2" vs 5/8" roof sheathing

I am having a house built in Orlando, Florida and I am concerned about the recent Hurricanes. A roofing contractor told me I was better off going with 5/8" plywood as opposed to 1/2" plywood for sheathing my roof. He also recommended using waterproof tape on the joints. Does anyone know if there is any difference(other then price) in using the 5/8'? What is the benefit or drawback. Thanks,
Old 12-30-04, 05:11 AM
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5/8 is good if you have snow build up.
You don't see so much the truss outline in it.
as for tape hummmmmmmmmmmmmm
he need to install H clips between the sheets of plywood for expension.
If your building a 2 story 1/2 should be ok
if you have a low slope or single story 5/8 will show less the roof truss outlin.
It your choice.
Why not go for 7/16 chip roof board.
Much cheapper there a green color to differed from the wall type
hope this helps

Old 12-31-04, 03:58 AM
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Well, 5/8" ply will certainly be stiffer than 1/2", but whether that amounts to more than a hill of beans is another question altogether. Assuming that this a shingle roof, the two big things I'd be more concerned about are 1) running a 4" band of roofing cement along the eaves and rakes and 2) using 4 nails per 3-tab shingle (code requirement in Florida except in Miami-Dade, where 6 nails are specified).

When you say "waterproof tape along the joints" was recommended, I'm assuming that the tape in question is Grace's "Ice & Water Shield" or the like. If the contractor recommended this be used to line the valleys then it is an excellent suggestion; if it was to put it on the joints between the plywood sheets, then it is a stupid one.
Old 12-31-04, 08:55 PM
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Wind Load

A 5/8th" ply roof deck can bear a greater wind load than a 1/2" ply roof deck.

That said, a 5/8th" roof deck is ALWAYS better than a 1/2" roof deck.

In Florida the difference can matter immensely as to whether your new roof deck meets prevailing code or will be blown away in the next gale.

You need to contact your local zoning/building code office and not accept soley what your builder says.

More important that roof deck dimension in Florida can be roof slope...since slope in Florida can determine whether any roof survives....

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