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.
Roofing over shingles.
If you choose to install metal roofing over shingles there are certain things you must keep in mind.
Things to know about metal over shingle roof problems.
Asphalt roofs typically last 20 to 30 years depending on the installation and shingle quality.
Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface.
Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros.
We re going to break them down so you know what to look out for.
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.
All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof.
Step 1 seek professional advice contact your local government office to inquire about local codes regarding installing new shingles over old ones.
Installation of metal roofing over shingles.
Although it sounds like a good idea we can assure you the cons heavily outweigh the pros.
After all you ll be making a significant and long term investment.
Before you reshingle a roof read our step by step guide for adding new shingles over old ones.
How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h.
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.
This is what it looks like when you install a steel shingle roof system over an existing asphalt shingle roof.
But first here are a few precautions about the underlying material.
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.
Adding new roofing over old sometimes called a re roof is possible only with asphalt shingles also called composition shingles.
Address any existing roof leaks and replace rotten rafters or.
When contemplating a new roof many people hope to simply do a shingle over and avoid the extra cost and mess of tearing off the existing roof and starting from scratch.
But before we get started one thing must be clear.
If you are trying to decide between the two materials it s important to carefully look at the metal over shingle roof problems.
Both metal and shingle roofs are great options for your next roofing project.
Re roofing over old shingles can save you time and money since you will not have to rip off the old roof and pay to have it hauled away.