For a second layer to be as good as a roof tear off you would have to have sound decking no leaks and a roof with no sidewalls where flashing is needed in order to tie the tiles in to the exterior walls.
Second roof layer.
If you don t tear off the old layer you can t examine the decking.
Apply the shingles to all roof planes ending a row of shingles at the top of the plane which is the ridge or peak and cut to follow the profile of any outside corners.
Plus depending upon the size of your roof you ve added multiple tons of weight which could pose a big problem if there is significant snow accumulation.
However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life.
Installing a second layer is only advisable if.
Most people would limit this practice to a total of two layers of shingles.
Inspect your attic for cracked or sagging rafters a sign that a layover could cause more damage.
If you have done some serious research on roofing then you have probably heard about adding a second layer of shingles on top of the old ones.
Replacing a roof can be very expensive and exhausting at the same time.
The standard practice was that you could install a new layer of singles directly over the old layer during a re roof.
Sometimes going over the top of your existing roofing is a cost saving alternative compared to removing the existing roofing and then installing new roofing.
Extra heat causes shingles to curl and break down much more quickly.
Re roofing options to tear or not to tear off.
This is mostly due to the fact that a brand new roof traps much less heat than a roof with multiple layers.
Pros and cons of adding a second layer of shingles.
You can t know for sure that there aren t any soft spots or.
You cannot afford to remove the existing roofing.
Roofing second layer of shingles roofing.
So if you re thinking of selling your home a few years.
Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing.
This provides added protection against ice dams.
Adds value a brand new tear off roof can add to your home s resale value and is a major selling point.
Select a length of roofing nails that penetrates completely through the new layer of shingles existing layer and the wood roof deck.
The second layer is also more difficult to install properly compared to new shingles.
Residential roofing codes allow your roof to have a grand total of two layers of roofing.
Posted july 31 2018 by onpage marie.
The additional weight of multiple layers may also be more than the roof supports can bear.
How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h.