Why Synthetic Underlayment Matters on a New Roof
Homeowners usually focus on the part of the roof they can see: the shingles, tile, or color. But one of the biggest product shifts in roofing is happening underneath the finished roof surface. More reroof projects are moving away from old-school felt and toward synthetic underlayment, and for good reason.
The underlayment is the layer between the roof deck and the finished roofing material. It is not the flashy part of the job, but it plays a major role in short-term weather protection during installation and as a secondary barrier if moisture gets past the outer roof covering. NRCA notes that underlayment serves several functions, including limited weather protection before the roof covering is installed and secondary weatherproofing if water infiltrates the roof covering.
That matters because traditional asphalt felt has some limitations. NRCA explains that some felt underlayments can wrinkle and buckle if they get wet before the roof covering goes on, and they generally should be covered as soon as possible after installation. The same NRCA source says synthetic underlayments are typically lightweight, high in tensile strength, have low or no moisture absorption, and experience less shrinkage and wrinkling.
In other words, synthetic underlayment is gaining attention because it can offer a cleaner, tougher platform under the finished roof. Owens Corning describes its ProArmor® synthetic underlayment as strong, durable, and water-repellent compared with 15-pound felt. CertainTeed describes DiamondDeck® as a premium synthetic underlayment engineered for residential roofing applications and says it is designed to resist tears, punctures, and impacts. owens corning
This is especially relevant in Southern California, where roofs are exposed to long periods of heat and UV, followed by bursts of wind-driven rain. A reroof here is not just about installing fresh shingles. It is about building a roof assembly that handles dry heat, seasonal weather swings, and the real-world conditions that show up during construction. If the outer roof covering is the armor, the underlayment is part of the backup defense plan.
There is also a code-and-standards angle worth watching. NRCA notes that synthetic underlayments complying with ASTM D8257 gained approval through code-change proposals with the International Code Council, even though older model codes did not specifically reference them by name. That tells you something important: synthetic underlayment is no longer a fringe upgrade. It is increasingly part of the mainstream conversation around better roof assemblies.
Of course, not all synthetics are the same, and underlayment is only one part of the system. The quality of installation still matters. Fastener pattern, overlap details, deck condition, flashing, ventilation, and compatibility with the final roofing material all affect performance. A better product does not cancel out rushed workmanship. But when a homeowner is already investing in a new roof, upgrading the layer beneath the shingles can be one of the most practical decisions in the entire project.
The biggest mistake homeowners make is treating underlayment like a commodity line item. It is not. On a well-designed reroof, the layers you do not see often determine how well the visible roof performs when the weather turns.
If you are planning a reroof, ask Rocket Roofing not just what shingle or tile is going on top, but what underlayment system is being installed underneath—and why that choice fits your home.
Real customers, Real reviews
Real customers, Real reviews
Rocket Roofing is professional and honest. Super happy with their service.
Alan and his company was very clean professional in doing the work. Out of 4 other companies, Rocket Roofing gave me a better price for the same work.
They did the work well and communicated ok
Roof repair for storm & wind damage. Professionalism, Punctuality, Quality, Responsiveness, Value
These guys are the absolute very best. They are very talented, smart they took their time explaining the process and followed through absolutely amazing. I tell you I e spent 22 years in the Marines these guys are top shelves
Excellent job. I would definitely recommend Rocket roofing. We really appreciate your work. Thank you
Rocket Roofing came through again for me on one of my investment properties in LA, not only did they do the job well, they were honest in letting me know my sky lights did not need replacement and saved me even more money! Highly recommend!
Great service, great employees and great experience overall. I have been working with Alan for over 2 years now. He and his team inspected the property I bought and made some repairs on the roof as well. They also offered a warranty work that I purchased (5 years warranty).After 2 years of wind and rain in San Diego, I started getting some leaks and sign of leakage couple of months ago, so I called Allen.
He sent the first available person after the rain was done and repaired the spot. I noticed the leak again after the next rain so I called him again. This time he send 2 people and replaced the entire section free of charge under the warranty work.
They also screwed in a tiny section of my gutter that was loose.
Overall I am very grateful to know Rocket Roofing and I will definitely contact him to replace a new roof when the time is arrived.
Alan and the guys at Rocket Roofing were absolutely amazing! They were responsive and very professional! They didn’t waste time and made sure that everything was complete and no additional damage was done. I would recommend them to anyone who needs any work done!
Great company to work with. Alan was very professional when inspecting my property, and his team did great job fixing my roof. Highly recommended.
This is the second time I have used Rocket Roofing and I am very happy with their work. They were extremely fast, friendly, professional and most importantly very affordable. I would highly recommend them to anyone in need of roofing repairs, especially for storm and wind damage. They are a top-notch company that truly cares about their clients and their work. I will definitely be using them again in the future!
I recently had a new roof installed by Rocket Roofing. The installation was done very professionally and on time. They were extremely responsive to all of my questions, even after we got started and the job was about 75% done, we had a few questions for them. They came back out to check everything a few days later and made sure it was right before moving on to the next phase of work. I received several quotes on our house before deciding on Rocket Roofing, they were by far less expensive than anyone else. Our home is much safer now that the roof has been replaced and I highly recommend them!
My roof was looking pretty bad after the last big storm we had. I called up Rocket Roofing to see if they could give me an estimate. They came out the next morning and gave me a very reasonable estimate. I was able to get the work done that afternoon so that my roof would not be damaged any further by another storm. The technicians were very friendly and professional, and cleaned up after themselves. My roof looks great! Thank you so much for all your help.
I recently had a new roof put on my home and I am so pleased with the quality, professionalism, and communication.Rocket Roofing came in to assess what needed to be done, let us know what he was going to charge and how long everything would take. He was right on time and completed the job exactly as he said he would. We will definitely use them again in the future!
Alan was phenomenal to work with. Always answered my call(s); if he wasn’t able, he returned my call promptly. He went out of his way to match the tiles of my Client’s home which we both were very appreciative of. Alan is a true professional.
I was extremely satisfied with my experience working with Rocket Roofing. The work quality was excellent, and the crew was extremely friendly and courteous. I would highly recommend them to anyone looking for roof installation or in need of repair work. My thanks to all at Rocket Roofing for a job well done!
Rocket Roofing did a great job on my roof. They were responsive to all my questions and took care of all the insurance red tape. The price was very reasonable and they did a great job cleaning up after themselves. I would highly recommend them.
Rocket Roofing is a trustworthy company that did a terrific job replacing our roof. We were very pleased with their timeliness, professionalism and overall knowledge of the roofing business.
Owens Corning Roofing Products
Owens Corning Roofing Products
Rocket Roofing is proud to be selected as an Owen’s Corning Approved Roofing Contractor.
Owens Corning is a leader in roofing shingles, underlayment and components products. The look of a roof can have a significant impact on the overall design and perceived value of a home. After all, the roof can make up half of a home’s exterior.
Owens Corning systems look better, last longer and offer more choices to perfectly fit your project.
Rocket Roofing is proud to be selected as an Owen’s Corning Approved Roofing Contractor.
Owens Corning is a leader in roofing shingles, underlayment and components products. The look of a roof can have a significant impact on the overall design and perceived value of a home. After all, the roof can make up half of a home’s exterior.
Owens Corning systems look better, last longer and offer more choices to perfectly fit your project.
