Do I need to remove old shingles before installing new shingles?

While a repair job can often be more convenient and somewhat more cost-efficient, placing new shingles over old ones is never a good idea. Whether repairing one section of roof, or a replacing a whole one, it’s always best to pull up the old shingles before putting down the new ones.

Can you put a second layer of shingles?

A second layer of shingles will decrease the integrity of your new roof and lower its lifespan. That’s because shingles aren’t designed to have a second layer of shingles on top of them! Plus, all that extra moisture and heat being applied to the first layer of shingles will make that first layer age faster.

Can you put plywood over old shingles?

The new plywood will have to be nailed to the rafters or roof trusses. That increase in weight should not be a problem with the single layer of asphalt shingles you will be installing, because it is normally safe to assume the roof structure is built to support the weight of two layers of asphalt shingle roofing.

Can you put a second layer of shingles over architectural shingles?

Re-Roofing Options – To Tear or Not To Tear Off Any more than that and you’d have to tear off the old shingles before installing a new layer. The quick answer is yes you can re-roof architectural shingles over existing architectural shingles (however you must check with the shingle manufacturer as well).

Why are multiple layers of shingles bad?

Two layers of shingles trap more heat, which in turn damages the shingles and shortens the life span of the roof. Adding a second layer could compromise the structure of your roof. Problems fixing leaks: A second layer of shingles only complicates the job when a roofer is trying to fix a leak.

Can you nail over architectural shingles?

We recommend only nailing over shingles that lay flat and have sufficient decking to allow for a second layer of roofing. When nailing over Laminate shingles please note that the shingles may be affected by the uneven cutouts of the shingles they are being applied over.