Roofing over an existing roof is also called reroofing or an overlay. It is the process where roofers install a new roof over your existing one, i.e. add a new layer of shingles, which means that the old roof will not be removed/teared off.
Can you put a new roof over an old roof?
The answer is yes, you can lay new roof shingles over old ones. … You can’t do it with wood or slate, for example, and you should never mix materials, such as laying asphalt shingles over cedar shakes. Also, the old roofing has to be in pretty good condition.
Should you 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.
Is 2 layers of shingles OK?
As mentioned above, homeowners are legally limited to two layer of roof shingles. Therefore, if you already have two layers, you’ll need a full tear-off. 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.
Should I tear off my old roof?
In most cases, more than two layers of roofing shingles does require a tear-off. Laying new shingles over old shingles is easily prone to leaks and reduces the life of the new shingles. This alone ought to be reason enough to do a tear-off; it’s just a bad value not to.
Is it OK to leave Old felt on roof?
6 Answers from MyBuilder Roofers
the old felt need to be stripped of back to the bare boards, then if they are ok with no rot you can over board them to give you a clean surface to attach your rubber to, do not attach rubber roof straight to the old felt.
Will black shingles make house hotter?
Black and dark-colored roofs.
In general, dark-colored roofing materials will absorb the heat and cause your attic and/or the top of your house to be warmer than a lighter colored material.
Can you roof over architectural shingles?
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). Having said that it will be nearly impossible to get a good looking quality installation.
How many layers should a roof have?
Most building codes allow two layers of organic or fiberglass asphalt shingles on roofs with a 4/12 pitch or less, and three layers on steeper roofs. If the structure can support the added weight, a typical 20-square (2,000-square-foot) reroof will cost at least $1,000 less than a tear-off job.
Can you put 2 layers of plywood on a roof?
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.
How many times can you shingle over a roof?
Depending on the type of roof material used, the number of layers added to a roof range from two to three times. House roofs should never exceed three layers of shingles. Adding additional layers without excavation can save homeowners up to $1,000 in labor.
How long does a roof overlay last?
On average, an overlay lasts around 16 years. That said, for most shingles, the warranty is valid for the same length of time whether the shingles were used in an overlay or a tearoff.
Does flashing go over or under shingles?
Instead of installing the step flashing between shingles, the flashing rests on top of the shingles. It’s not unusual to see sealant installed when sidewall flashing is missing. Sealant will eventually dry, shrink and crack. You’ll see sealant substituted for flashing in a lot of different areas on roofs.