This synthetic layer which replaces felt paper covers the entire roof deck and is the second line of defense against leaks after the shingles.
Will roof shingle warranty be void if a second layer.
Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.
All gaf roofing shingles and qualifying accessories the gaf products come with the great coverage provided by the gaf shingle accessory limited warranty and you don t need to do anything at all to get it.
This is especially true if there is huge snowfall.
Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.
In most cases if not all if you install a new roof on top of your old roof it will void the warranty.
Be sure to check with the shingle manufacturer regarding all warranty issues and installation requirements before re roofing.
You could be adding weight to your roof with a second layer that your house cannot handle.
Having an old layer of roof shingles under your new layer accelerates that process as the original layer holds a lot of heat.
It can also cause the new shingles to stick to the old shingles causing bulges.
This will force you to replace your roof earlier than expected.
There are a couple reasons for this.
Manufacturers believe that layering the roofing diminishes the overall performance of the roof.
In the event you experience a problem with your gaf products caused by a manufacturing defect this warranty is a great start.
Reasons why you should not add a second layer of shingles it will shorten the lifespan of your roof the second layer of shingles will trap heat which can result in the decomposition of both roof layers.
You are correct that second layers typically don t last as long as single layers.
A second layer of shingles will expend heat more slowly which will shorten the shingle lifespan.
Adding this membrane isn t an option with a re roof and the extra layer of shingles offers little protection against ice dams.
That in itself eats away at the savings.
Most people want to add another layer to their existing roof to save money.
For many reasons we don t recommend this and encourage you to be suspect of any company that wants to do it to cut costs.
That second layer of shingles won t last as long.
Installing a new roof on top of your old roof will void or shorten your warranty in most cases.
Asphalt roof shingles remain waterproof until they dry out.
Before you reshingle a roof read our step by step guide for adding new shingles over old ones.
