# Plywood over furring strips?



## Ed the Roofer (Jan 27, 2007)

Are these firring strips being used to fill in the gaps on a skip sheathing deck also called spaced board plank decking, or were firring strips nailed on top of the old decking to elevate the original cedar shingles off of the deck for under cedar breathing capability?

If you are installing cedar shingles back again, then it would be to the materials advantage to still have the air gap created by the firring strips. If you are having asphalt composition shingles installed, then it would be better to install them on top of a solid deck, if I interpreted your question correctly.

If you would like to scan and attach copies of the contracts to be reviewed, feel free to e-mail them to me through the profile section, and if you have a diagram with measurements, that would help too.

Ed


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## the roofing god (Aug 2, 2007)

as long as the skip sheathing is in good shape ,there`s no reason to take it off,typically we will go over it w/ 1/2"plywood,and use dripedge on the rake eave to cover the height difference---now if you remove the skip sheathing whose thickness is approx. 1 1/4",and then he puts even 3/4"plwood,there would end up being a dip at the roof edges because the sheathing(plywood) would be lower than the wood rake trim,another point to consider also is that most of the crown molding used on the rakes of these homes is also nailed into the skip sheathing,if those nails are removed and he puts plywood-renailing the molding to the plywood edge will not work as well.Idefinitely think you`re much better off with the 1/2"plywood over the skip sheathing(slats)


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## oldfrt (Oct 18, 2007)

the roofing god said:


> as long as the skip sheathing is in good shape ,there`s no reason to take it off,typically we will go over it w/ 1/2"plywood,and use dripedge on the rake eave to cover the height difference---now if you remove the skip sheathing whose thickness is approx. 1 1/4",and then he puts even 3/4"plwood,there would end up being a dip at the roof edges because the sheathing(plywood) would be lower than the wood rake trim,another point to consider also is that most of the crown molding used on the rakes of these homes is also nailed into the skip sheathing,if those nails are removed and he puts plywood-renailing the molding to the plywood edge will not work as well.Idefinitely think you`re much better off with the 1/2"plywood over the skip sheathing(slats)


:thumbsup:
Good advice,
Also ,if the skip sheathing is removed,there is the consideration of the distance between the rafters.On a lot of these homes the rafters are farther than 16"OC and need a heavier plywood than1/2".


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## sandyman720 (Mar 6, 2007)

Yes the roofing god explains my situation better than I could. THat is exactly what they want to do.

I will have to go up in the attic and see but I think the rafters are 16" oc


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## the roofing god (Aug 2, 2007)

these are typically older homes,I`m in a very historic area of new york and there are hundreds to thousands of these, the other thing is that on these homes you usually don`t find the rafter layout so neat instead of 24"on center,you find a lot of rafterspaces 26-30",in these situations,you need to make sure the plywood ends on rafters ,and is nailed w/ 10d nails rather than being rabbit nailed into the skip sheathing,this makes for a stronger install,when "rabbit"nailed on the skip sheathing the plywood ends tend to pull up over time--some contractors do it that way because beginning and ending over rafters means a higher waste percentage


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