New Roof Old Plywood

Remove the old roof.

New roof old plywood.

If you can see original wood shingles on the underside of your roof when you re up in the attic you ll need not only to tear everything off but also to install new plywood decking all of which likely adds 5 000 or more to your costs. Unfortunately because the roof sheathing isn t normally visible damage can go unnoticed by homeowners. In addition to installing a new roof you might need to. Be sure to weigh the advantages and disadvantages of each option before you decide which way to go for your new home or your updated roof.

If the old plywood had been removed. Roy gingrich of ellicott city has a 40 year old house with an asphalt shingle roof surface. Here is approximately how much different options cost. Sometimes referred to as roof sheathing or a roof deck this plywood acts as a foundation for the layers of underlay and the shingles on your roof and connects the roof to the frame of the house.

5 8 inch 26 87 per sheet. The existing asphalt shingles need replacement so he plans to do a tear off and re shingle. The tear off gets a lot more complicated if you have something other than asphalt up there. After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood.

One thing to consider is that the new plywood probably wants to be the same thickness as what would be used if it was used by itself on the rafters i e. Remove any old roofingnails refasten any loose wood and replace any rotten or damaged wood asnecessary to properly install new roofing. Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. Cost to install flashing on roof.

This means that you must replace old roofing plywood. Replaced wood will cost additional xx for one sheet of 1 2 cdx plywood or x xx per linear foot of 1 x8 board. Both osb and plywood for the roof have been approved for use so it may come down to what you feel most comfortable using. This will ensure that the strength of the plywood is enough to bridge spots on the roof where the old plywood was weakened to the point that it would sag under the load on the roof.

Even though it isn t visible it is very important to the structure of your home. Open spaces form between the once tightly fitted shiplap boards. As long as the new plywood itself can span the distance and carry the roof wind seismic and snow loads for your region adding new ply over old is just fine.