Do you need to replace your home's old roof and do a complete tear-off? Thankfully, this will give you the opportunity to replace the underlayment material. This is the protective barrier that goes between the roof deck and the roofing material. With there being two main types of underlayment material, you may be wondering which is best at giving your home that extra protection that it needs.
Synthetic Underlayment Material
Many roofing contractors these days are using a synthetic underlayment material over its tar paper counterpart. It's a lighter material, which makes it easier to carry up on the roof when your roofing contractor performs the installation. The rolls are also bigger than tar paper roles, so fewer passes will need to be made with the synthetic material to cover the entire roof. The synthetic material itself is also very strong and can withstand the wear and tear of walking on it during the installation process.
One of the downsides to a synthetic underlayment material is that it doesn't breathe very well. This is typically not a problem if you have soffits that are not blocked and letting heat out of your attic. However, those that don't have soffits are going to have the roof decking deteriorate faster if the heat and moisture are trapped at the top of your attic.
That said, synthetic material is going to do a great job at repelling water. While the hope is that your roofing material doesn't come off the roof and expose the underlayment material, you are going to have more protection by having synthetic material on the roof.
Tar Paper Underlayment Material
Tar paper has been used for a very long time as a roofing underlayment material. The benefit of using tar paper is that it is cheaper than synthetic material and has a long lifespan. The only catch is that the roofing contractor will have to be careful when walking on the underlayment material once it has been placed on the roof because it can tear from not being careful with the material.
In comparison to synthetic material, tar paper is going to let more heat and moisture out through the material and be more breathable. This may mean that you want to use tar paper if you have an older home without a lot of soffits and need to make sure that all the moisture isn't trapped in your attic.
Contact a local roofer to learn more about roof replacement.