We are really talking about two different issues.
2 laycers on a roof.
A roof is one of the most vital components of a house.
If you don t tear off the old layer you can t examine the decking.
You can t know for sure that there aren t any soft spots or.
Multiple layers of composition roofing and composition over a wood shingle shake roof.
Now you just have to decide whether to remove the existing roof shingles or recover the roof.
Pros to overlaying a shingle roof.
Replacing a roof can be very expensive and exhausting at the same time.
Pros and cons of adding a second layer of shingles.
Two roof layers can work if the existing roof is in good condition but you shouldn t put more than two layers of shingles on your roof because of the weight.
For a second layer to be as good as a roof tear off you would have to have sound decking no leaks and a roof with no sidewalls where flashing is needed in order to tie the tiles in to the exterior walls.
Here are the layers of a roof in order of application bottom to top.
So anywhere along the gable end that you can see the felt you ll see two layers.
It provides structure by tying the trusses and joists together.
Here are the pros and cons.
Decking most often made out of plywood this roof layer is installed over the framing in a typical roof install.
Assuming your roofing contractor is using standard 36 wide 15 roofing felt double coverage means that each layer of felt put down across the roof laps 19 over the upper half of the previous course.
When a buyer is purchasing a home their homeowner s insurance carrier will inquire about the age of the roof and the number of layers.
Despite these drawbacks layering shingles can still be the best plan for your roof.
You can usually see the underside of plywood decking from the attic.
Posted july 31 2018 by onpage marie.
If you have done some serious research on roofing then you have probably heard about adding a second layer of shingles on top of the old ones.
Re shingle roof as part of a larger plan.
But contractors who spoke with angie s list say best practices call for stripping the roof down to the wood deck to inspect it before installing a new roof.
The first course starts with an extra 1 2 wide run.
If you do remove the old shingles you will end up with a nice fresh layer of felt on the roof deck.
Two layers of shingles trap more heat which in turn damages the shingles and shortens the life span of the roof.
One of the situations where this option can make the most sense is for a temporary fix as part of a long term plan.
Most cities and towns allow a maximum of two layers of shingles says chad muth president of muth company roofing in westerville ohio.
Saving on the initial shingle installation doesn t solve the long term cost of adding a second layer of shingles.
First of all multiple layers of shingles simply means layering a new asphalt shingle roof on top of the old one rather than stripping the roof completely to expose the sheathing and replacing it with new shingles.