Synthetic underlayment
A synthetic underlayment is an essential roofing layer that provides additional protection against moisture and the effects of outdoor elements. 

This blog about synthetic underlayment is part of a 6 part series on roofing underlayment. To access the main page of this series and learn more go to Roofing Underlayment 101: An Overview Of Roofing Underlayment.

A key innovation in roofing over the last 10-15 years has been synthetic underlayment. Back when I started roofing more often than not we would install drip edge and ice and water shield around the base of the roof and get right to shingling. Every now and then we would install felt paper which is a very poor knock off of today’s better products.

Today, synthetic underlayment is an important roofing layer that acts as a buffer between the roof deck and the shingles. It also affords the roof additional protection against moisture and the effects of outdoor elements. Let’s look into a few of the reasons why synthetic underlayment is important. 

1. Affords Additional Protection 

In the Hamilton area, our roofs get hit hardest on the south side due to the sun. This means that one side of the roof will usually deteriorate far faster than the others. In such cases, you will be glad you had synthetic underlayment installed. The reason for this is simple: you do not need to be concerned about significant deterioration towards the end of your roofs life with synthetic installed.

The reason for this is that if you have synthetic underlayment installed, you will have an additional layer of protection against moisture and rain, even if your shingles fail. This allows you to prolong the life of your roof by a number of years, free from concern that it will lead to leaks inside your house. Underlayment provides a weather and tear resistant second layer of protection to your roof. Towards the end of your roof’s life cycle you can push it that much longer knowing you are covered!

Underlayment is especially useful for protection against the moisture. Water, vapour (and eventually mould) can slip through cracks, nail perforations and other exposed areas of your roof uncovered by shingles even on a well installed roof. An installed underlayment virtually eliminates such prospects. 

2. Longer Lasting 

Synthetic underlayment keeps the shingles up off the roof deck so that they are not in contact with the organic material in the wood. Installing underlayment not only allows a smoother surface for your shingles to lie on, it also allows them to breathe and circulate air easier which helps regulate their temperature. We wrote a blog on thermal shock which explains why lack of temperature regulation can dramatically decrease the life expectancy of your roof!

Since your roof is better shielded from the elements because of the underlayment, it helps extend its lifespan. Repairs or replacement are far less frequent and it is not uncommon for a roof installed with a high-grade underlayment to last decades in relatively pristine conditions. 

3. Cost-Savings

While a roof installed with an underlayment may have a relatively higher initial cost, it remains a more economical option in the long-run. As already mentioned, there is far less need for any repair work in the future, which helps with savings. 

In addition, leaks can not only harm your roof but also your home’s walls, appliances, electrical and furniture that may become exposed to it. Since underlayment greatly mitigate risk of leakage, such issues and their accompanying costs are avoided.

4. Fire-Resistant 

Modern underlayment generally features high fire resistance, helping reduce the risk of fire as well as preventing its spread. 

5. Keeps the Indoor Temperature Stable

Modern underlayments are useful for helping keep temperatures indoors stable and comfortable due to their good insulation properties. A quality underlayment installed can go a long way in ensuring that its effects indoor are mitigated. 

Concluding Note 

Roof underlayment holds many benefits and little drawbacks. However, an underlayment only performs well in its function if it is installed correctly. A botched job by an unqualified team can lead to a whole host of issues. Don’t take the risk – always work with professional roofers who are well-experienced for the job. If you are a resident of Hamilton or surrounding areas, consider hiring the pros at Peak Roofing. For a free estimate or any queries, call us anytime at 905-746-5792 or email us at

Published On: April 26th, 2020 / Categories: News / Tags: /

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