Install underlayment between the shingles and the new metal roof.
Underlayment for metal roofing over shingles.
And keeps the rough surface of the shingles off the backside of the metal roofing.
Selecting the right underlayments for a lifetime metal roof should be a primary concern for anyone thinking about specifying or choosing to install a metal roof on their home.
Address any existing roof leaks and replace rotten rafters or.
If your metal roof is to be installed over solid decking or over existing shingles an environmental benefit a layer of quality underlayment between the two is essential.
Underlayment must also act as a secondary weather barrier in case the roof fails.
Traditionally metal roofs have used standard 30 pound felt paper underlayment.
We re going to break them down so you know what to look out for.
But first here are a few precautions about the underlying material.
Our metal roofing profiles.
However contractors now recognize the benefits of synthetic.
The first one being that the new.
The industry standard for underlayment is often thought of as felt paper tar paper but there are also many newer synthetic underlayments that are designed.
Underlayment is also a good idea when the roof is installed over battens though a natural tendency for the underlayment to drop between the battens can be a problem.
This provides a couple of benefits.
2 install underlayment right over the shingles before installing the metal roof the second way to install a metal roof over a shingle roof is by applying an approved underlayment right over the old shingle roof.
The main benefit of doing it this way is that it is the fastest way to install a new metal roof over a shingle roof.
A layer of underlayment installed on top of the existing shingles will help keep the granules of the old shingles from rubbing against the back of the metal and causing possible corrosion.
So when we talk about metal roofing over shingles how does it work.
Installing a metal roof over shingles can also result in an increased chance of trapped water vapor and moisture between the new roof and old roof resulting in new mold and rot.
By removing the old roof before the new roof s installation you are able to give the underlayment a thorough inspection to ensure there are no damages that could.
Installation of metal roofing over shingles.
The first goal of roofing underlayment is to keep the roof deck dry before installation of the metal roofing material.
The first way is to run new underlayment over the existing shingle roof completely covering the old roof.
This can be synthetic underlayment preferred 30lb felt or a double bubble radiant barrier.