According to the international existing building code homes can be re roofed one time by applying a second layer of roof shingles over the existing one but after that application begins to wear both layers need to be removed before a brand new roof is installed.
How legal is 3 layers of shingles on a roof.
When it s time to replace your roof there are several factors that might lead your roofing professional to recommend adding shingles on top of your existing.
A bundle or package of shingles weighs about 70 pounds depending on the type of composition shingle.
Pros to overlaying a shingle roof.
1 the roof was recently re done with 3 layers of shingles and this is not allowed by code which is the case in most places 2 no building permit which is typically required was pulled before the roof was done.
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.
Benefits of adding multiple shingle layers.
There are important reasons why this code is in effect.
The best life will come from removing all the old layers down to roof boards or sheathing and then laying down the new roof on a well repaired flat surface.
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.
Re roof or strip the roof down.
So let s say we have a hail storm and the roof takes a beating.
That limit pertains to roofs with up to a 4 12 pitch.
Once you have discovered how many layers of roof shingles are allowed the next decision you should make is whether you will have the existing shingles completely removed to make way for two or three new layers or whether you will have another layer of shingles placed on top of the existing layer.
Most building codes allow up to two layers of organic or fiberglass asphalt shingles.
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.
Layers of shingles on top of each other shorten the life of the roof due to the newest layer sitting on an uneven lower surfaces.
Here are the pros and cons.
When a home has two layers of shingles the trusses are supporting twice the normal weight of a single layer roof.
In both cases more layers means a more costly roof claim.
Now you just have to decide whether to remove the existing roof shingles or recover the roof.
Roofing layers from the framing to the shingles.
So we ll start at the bottom of the deck and work our way up through all the roofing layers until we reach the shingles and sunshine above your roof.
Then you have a good case against the seller.
If the roof has multiple layers typically the insurance company will only insure the top layer.