Whether you are considering having your home re-roofed or whether you simply want to upgrade your existing roof you should consider how many layers of shingles you can and should have on your roof. In some states and for certain types of building you will require a permit to have more than two layers of shingles. You should also check with a roofing contractor that your roof and the building itself could cope with the extra weight burden that would be placed on them.
Obtaining a building permit
A roofing contractor will know how many layers of roof shingles are allowed in your area for your building but it is normal that you will be permitted up to three layers of shingles. In most cases two layers of shingles is advisable and three aren't normally required but if you live in an area that suffers from particularly strong wind or lengthy periods of heavy rain then you may want to consider a third layer. You should consult a roofing contractor to ask them whether you require a permit because even if they don't know off hand they will know the correct people to contact.
General building codes
Generally it is fine to have three layers of shingle but you should check this with your local building permit people and you should make sure that your roof and the rest of the structure have the strength to cope with the extra weight. In some areas it may be necessary to obtain a permit to re-shingle your roof at all, but without the required permit your new roof is not legitimate. Make sure you know how many layers of roof shingles are allowed on your roof.
Re-roof or strip the roof down
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 new shingles or whether you will have another layer of shingles placed on top of the existing layer. Having the old shingles removed before the new shingles are installed will incur more labor couts but laying more shingles down on existing shingles can look untidy if the original layer are damaged in any way. The best bet is to have all existing shingles removed and new ones added in their place. Finding out how many layers of roof shingles are allowed is only the first step in having shingles added or replaced on your roof.
Copyright 2004 Roofer 911.com. All Rights Reserved
by Steven Briesemeister. Reprinted courtesy of Roofer 911.com, roofing contractor serving Long Island, Queens, Brooklyn, NY and northern Virginia.