Since the second layer makes removal more difficult you will find roofers have to work longer to get the surface ready for a fresh layer of shingles creating higher labor costs the second time around.
Can you have two layers of shingles on a roof.
Pros and cons of adding a second layer of shingles.
If two layers already exist you ll need to remove the old layers before installing a new layer of shingles.
A roof is one of the most vital components of a house.
In most areas building codes allow for up to two layers of shingles installed on a roof.
Replacing a roof can be very expensive and exhausting at the same time.
Any more than that and you d have to tear off the old shingles before installing a new layer.
If you don t tear off the old layer you can t examine the decking.
Any more than two layers of shingles can be too much for the roof to handle even if the local building codes don t outlaw it.
When it s time to replace the roof again and you have no choice but to start anew two layers is the maximum allowed in most areas you ll have to pay extra for the two layer tearoff and disposal.
Most cities and towns allow a maximum of two layers of shingles says chad muth president of muth company roofing in westerville ohio.
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.
The average 30 square roof uses 90 bundles of shingles and a bundle of asphalt roofing shingles weighs about 100 pounds which means you re putting roughly 9 000 additional pounds of weight on your roof.
Though both these points are valid you will end up spending the same amount of money or more later to have two layers of shingles removed.
Additionally if your roof is severely damaged it likely won t be able to support the weight of a reroof and will need to be torn off.
Having multiple layers of shingles is going to make your roof hotter because the heat gets trapped between the layers.
Eliminating the tearoff can easily save 1 000 or more on a new roof but you re really just delaying the cost.
Most people would limit this practice to a total of two layers of shingles.
As mentioned above homeowners are legally limited to two layer of roof shingles.
The standard practice was that you could install a new layer of singles directly over the old layer during a re roof.
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.
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.
