The most efficient and cost effective option is to resheet directly over the shiplap with exterior grade plywood. This is acceptable by code, as well as the roofing manufacturers. Your new composite shingle will be installed securely to the new solid surface and last for years leak free.
Can you put new plywood over old on a roof?
The new plywood will have to be nailed to the rafters or roof trusses. … But, with the old plywood left in place, it will be considerably more difficult to locate the rafters to ensure proper nail placement.
How long does plywood last on a roof?
There are a few averages you can expect, but they are dependent on these factors. Plywood siding, such as T-111 should give at least a 35 year life expectancy, if finished properly; but there are many cases of it lasting over 50 years. Roof sheathing should last 30 to 40 years or to put it another way, two roofs.
What thickness plywood do you use on a roof?
Most roofs will be sheathed in plywood at least 3/8 inch thick. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Loads will vary with the pitch of the roof; the flatter the roof, the greater the load on any one section. Steeper roofs will have lighter loads per square foot.
When did they start putting plywood on roofs?
And as the courts decide who is responsible, developers have spent millions replacing defective roofs and homeowners have begun organizing to demand reimbursement. The plywood was introduced after fire codes were changed in the early 1980’s, just in time for the long nationwide building boom.
What goes over plywood on roof?
Roof sheathing, also known as roof decking, is a layer of plywood or OSB that covers the trusses and joists, which are the beams that make up the roof’s skeleton shape. Roof sheathing goes above the roof’s framework but below its shingles. That is because roofing shingles and tiles need a layer of support to rest on.
What side of plywood goes up?
The side with the stamp is the smoother side. When installed smooth side down, the rough surface will then face up and give the worker traction for safety.
What kind of plywood do you use for a flat roof?
A flat base is required to lay the roof covering on. This can be either Smartply OSB3 or good quality, structurally sound WBP plywood. A minimum thickness of 18mm must always be used. Depending on the building use insulation could be required to construct a ‘warm roof’ build-up.
What is the best thickness for roof sheathing?
The recommended thickness for roof sheathing is ⅝” thick. Sheathing with a thickness of less than that is much more likely to result in bowing between framing which could potentially compromise your exterior roof material.
Can you plywood over shingles?
New wood shingles (not located in Very High Fire Hazard Severity Zones), or asphalt shingles with self-sealing tabs, or built-up roofs may be installed directly on existing wood shingles with or without a solid sheathing, or plywood base. … Plywood shall be installed as noted in Item 6 below.
Can I put decking over plywood?
The only kind of plywood you should use as decking material is marine plywood. … Marine plywood is seven to eight layers thick, and the epoxy used to bind the layers is waterproof. On top of that, the plywood itself is treated with a waterproof sealer.
Do I need to replace the plywood on my roof?
If you are getting a new roof, while you may not necessarily need to have the plywood decking replaced, you should have it carefully inspected by a qualified roofing contractor. The inspection should take place when the old shingles have been removed.
How much does it cost to put plywood on a roof?
The thicker the plywood your roofer uses, the more expensive the job will be. Your price could vary depending on how much the roofing company charges for labor, but generally, you can expect to spend between $70 to $100 for each sheet of plywood.
How do I know if my plywood is bad on my roof?
Bowing or bulging: Moisture and wood rot may cause your decking to sink in or swell up. From the outside, this looks like you have a bulging or bowing spot on your roof. The shingles above this spot may not function properly. Further, the decking can eventually fall in.