Installing new roof shingles over old effectively doubles the weight of the roofing so you have to make sure your roof structure can handle the extra load.
Shingling a roof over old shingles.
Use a flat pry bar.
Use 1 5 or 1 75 inch roofing nails.
Installing a new roof over shingles takes less time than tearing off the old roof.
1st and foremost your existing roof needs to be in reasonable shape.
If the job is done correctly with the new layer of shingles laid flat over the existing shingles the old roof cushions the new one and serves as a secondary barrier should wind or water ever break through the new shingles.
Ask this old house general contractor tom silva reveals the best ways to secure shingles to a roof.
All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.
Doing it now will make it easier to keep the reroofing job clean.
Rather than ripping off your old roof and putting a new one down you simply add a layer of shingles to your existing roof.
How to roof over existing shingles.
Looks just as good and lasts as long.
Whether it is the right choice for you depends on your home and the condition of your roof.
See below for a shopping list tools and steps subscr.
Leave the old valley flashing in place and install new over it.
How to do it remove caps.
Remove air vents and pipe flashings by prying out or unscrewing the fasteners holding the fixture.
That s also why building codes commonly limit re roofing to no more than two layers.
Remove the ridge caps.
Place the top of each starter shingle firmly against the bottom of the shingle immediately above it and even with the eaves then nail it into place.
As long as it s done right and under the right conditions installing new shingles over old ones can last as long and look just as good as a complete re roof.
If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.
To shingle on top of existing shingles there are a few things you want to make sure.
Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones.
Has the same manufacturer s warranty.
To level out an existing asphalt shingle roof rip down reduce the height of two courses of shingles as shown in the drawing below.
If a shingle is.
Overlaying your existing roof also comes with its own set of pros and cons.
Because asphalt shingles are routinely exposed 5 in rip down the first strip the starter course so that it is 5 in.
Manufacturers will still warranty the roof for the same amount of time as a re roof as long as it s done by a qualified installer.