What is a Modified Bitumen? – On the House

What is a Modified Bitumen?

By on October 5, 2015

Question: I have an old tar-and-gravel roof that I am getting re-done. My contractor is suggesting a “Modified bitumen” roof. What is this? (John, San Mateo CA)

Answer: Modified bitumen roofing is made of asphalt that has been modified with polyester. A conventional tar and gravel roof can tear as it expands and contracts with changes in climate and temperature. Modified bitumen is far more flexible and therefore less likely to crack or tear.  There’s a single-ply version, but you will be much better of with more than a single layer.

For more home improvement tips and information search our website or call our listener line any time at 1-800-737-2474! All you need to do is leave your name, telephone number and your question.


About onthehouse

You must be logged in to post a comment Login

Leave a Reply

Pin It on Pinterest