We have a few people ask us every year if we can shingle over their existing shingles. (Usually to cut costs). While this might shave a few dollars off in the beginning in tear off cost and time, it will likely not save you money in the long run. Shingling over existing shingles will not only cause major issues and possibly even leaks but it can also void your warranty and shorten the life of you roof significantly.
Still think it sounds like a good idea? Here are 5 reasons to reasons to tear off your existing shingles.
- Code may not allow it.
a. Your roof is most likely not designed
to hold that much weight especially if
you are in an area that gets heavy
snow. This can cause excess stress on
rafters. - Repairs will likely still be necessary
a. When you add a second layer of shingles roof vents, pipe boots and flashing do not get replaced which will in turn result in the same leaks that led you to need a new roof in the first place. - Shingle life span will be cut down
a. Installing another layer of shingles on your roof adds another heat absorbent layer and often adds another place for moisture to get trapped this can cause your roof deck to rot and mold to occur. This extra moisture and heat will break down your shingles much faster than normal. - Warranty could be voided
a. There are necessary requirements needed to comply with most manufacturers warranties without installing a second layer. Shingles must be installed according to manufacturer specs. Most, if not all shingle manufacturers require the first layer to be removed if registering a warranty. - Less liability?
a. It might seem logical to think that there is less liability involved if the initial layer of shingles isn’t removed prior in installation, but that is not the case. Leaving that first layer on will cost more money in repairs, insurance coverage, tear off the next time the roof is replaced, added weight, and resale value.
We always recommend installing the roof correctly the first time as we believe it is in the customer’s best interest.
