What’s the Best Underlayment for a Metal Roof? Reviewing DELTA®-TRELA

Metal roofs offer great durability and can last for around 75 years – a significantly longer lifespan than traditional asphalt shingles. Metal roofs are also a popular choice for architects and builders when it comes to energy efficiency because of their reflective properties. It benefits green building as well because they are often made from recyclable materials.

One important thing to remember when installing a metal roof is to include an underlayment in the construction process. But what’s the best underlayment for a metal roof, and how do you correctly install the product?

In this episode of The Build Show with Matt Risinger, Matt talks about metal roofs, what the best practices are for metal roof underlayments, and shows off the many features and benefits of what he considers one of the best underlayments for metal roofs: DELTA®-TRELA underlayment.

Why does a metal roof need an underlayment?

Metal roofs are prone to having condensation form on the underside. As well, water can enter during an intense rainfall or storm. Having a metal roof without an underlayment can cause rust and damage, reducing its performance. Adding an underlayment to a metal roof provides an air gap that allows any condensation and moisture to dry out, eliminating the risk of corrosion or damage.

Do you need a ‘breathable’ metal roof underlayment?

Metal roofs aren’t completely waterproof, so there needs to be an underlayment that allows for adequate airflow to effectively dry out any moisture. The DELTA®-TRELA system is a breathable, or permeable, underlayment that’s an all-in-one solution thanks to its built-in air gap. Featuring 3-ply, spun bonded polypropylene, this commercial-grade, high-permeance metal roof underlayment ensures air tightness, saves time, and costs with installation, and reduces noise from rain and hail by up to 15 decibels.

How to install metal roofing underlayment

In Matt Risinger’s DELTA®-TRELA review, he talks about how you can easily install the DELTA®-TRELA roofing underlayment.

metal roof underlayment installation metal roof underlayment installation

Every roll of DELTA®-TRELA includes fasteners for straightforward and consistent installation. DELTA®-LFS and DELTA®-MULTI-BAND can also be used to seal any gaps and seams.

Learn more about metal roof installation and underlayments

Interested in learning more about DELTA®-TRELA? You can watch High-Performance Buildings with Dörken – DELTA®-TRELA, where Krzysztof Apriasz, a certified Passive House Consultant and experienced technical services manager, covers some of the unique product features and its benefits to builders and installers.

DELTA®-TRELA metal roof underlayment

You can also read about the many benefits of metal roofs in building design, which provides a more detailed look at how metal roofs can offer reduced heating and cooling costs, greater energy efficiency, longevity, and more.