Cedar shake can also go for about three decades.
How long does a second layer roof last.
But because of the amount of prep work involved in overlaying a roof properly any savings are usually modest maybe 25 percent compared to a new roof.
You could be adding weight to your roof with a second layer that your house cannot handle.
Most homes have asphalt or composite shingle roofing which normally last about 20 years.
You are correct that second layers typically don t last as long as single layers.
A ribbed metal panel roofing system featuring concealed fasteners will offer a longer lifespan ranging from 30 to 50 years depending on the environment.
Adds weight you re literally adding another roof to the top of your home so if your home is older or is not structurally sound you may not even be able to complete this type of roof job.
And shingles have started to separate.
It will shorten the lifespan of your roof.
Installed correctly a new roof will last at least 15 years but the exact lifespan depends on the material.
That second layer of shingles won t last as long.
Here learn which roofing lasts the longest.
The second layer of shingles will trap heat which can result in the decomposition of both roof layers.
Still you ve got no less than 17 years from it already.
The shingles likely won t last as long so the job could actually end up costing you more in the long run.
However there are premium brands that can serve you diligently for 50 years.
This will force you to replace your roof earlier than expected.
Won t last as long generally speaking the shingles that are laid over the old roof won t last as long as their natural lifetime due to extra heat trapped by the added layers.
In fact the extra layer can reduce your roof s lifespan by up to 40.
I don t know if a precise formula like that exists but the second layer does have less firm foundation than the first and it would be logical to expect shorter life span.
Fiber cement can go up to 25 years and the thicker asphalt can give you about 30 years.
Asphalt roof shingles remain waterproof until they dry out.
With proper installation you can expect a 25 to 40 years lifespan from a ribbed metal roof with exposed fasteners.
But because of the amount of prep work involved in overlaying a roof properly any savings are usually modest maybe 25 percent compared to a new roof.
The shingles likely won t last as long so.
That in itself eats away at the savings.
I think you ve got a good life out of it.