If one needs a new roof, it’s not recommendable to add a second layer of roof shingles over the existing one. People usually want to save time and costs on roof replacement, so they decide to just keep the old shingles without complete replacement. What is more, they claim that adding a new layer of shingles over the existing one prevents mess and time-consuming roofing services. However, certified roofers from DNB Construction LLC claim that adding brand-new roof shingles over old ones isn’t a good idea. They explain it with many potential issues that may occur in this situation, specifically when the old roof shingles are covered with moss.
We listed several reasons for not adding a brand-new roof over the existing one with moss.
First, it’s not a good solution to cut off moss from sunlight, because it will stay on the roof and be a source of water collection. What is more, mold may appear with a lot of infections that can spread into the attic. Moreover, both mold and rot are harmful to wood structures, so the drywall can be damaged.
Second, a lot of moss can ruin the underlayment and existing roof decking. It is good to remove the roof shingles and inspect all layers to guarantee the top quality of the new roof. So, moss can’t immediately day and it can continue to increase the possibility of the roof collapsing.
Third, roof bumps and dips in the surface of the roof can prevent the proper sealing of the new layer of shingles. This happens because of the combination of swollen and damaged decking with moss that grows rapidly.
Forth, roof shingles with moss are unsafe for roofers who have to walk on the old roof during the installation of the new roof. What is more, moss makes very unstable ground prone to sliding and slipping.
Fifth, by adding a new layer of shingles over the existing one that may be moss-covered, a limited warranty on the novel roof can be voided.
Its team of well-coordinated roofing technicians is there to visit your place and objectively assess it. Call us at (301) 362-7663 or fill out our contact form to request a quote.