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Can You Use Roofing Felt On Walls

November 30, 2025

2 min read

dilshadakram

You can use roofing felt on walls, but it is not the best choice for most projects. Roofing felt is made for roofs and works best there. Walls need different protection. Roofing felt can trap water on walls and cause mold. It also breaks down faster when exposed to sun and wind on a vertical surface. There are better wall materials available.

What Is Roofing Felt Made for?

Roofing felt is a thick paper or fabric layer that goes under roof shingles. It protects the wood deck from water and ice. The felt absorbs some moisture but lets air flow through it. It is designed to work on sloped roofs where water runs down and off quickly.

Roofs need this layer because they face direct rain and snow. According to industry data, asphalt shingles account for approximately 80% of residential roofing projects in the U.S., and these almost always use felt underlayment. The felt helps these shingles last their full lifespan, which ranges from 20 to 30 years for basic asphalt shingles.

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Why Walls Are Different from Roofs

Walls are vertical, not sloped. Water does not run off walls the way it runs off roofs. If you put roofing felt on a wall, water can pool behind it. This creates a wet spot where mold and mildew grow.

Walls also face different weather. Sun and wind break down roofing felt faster on walls. According to the National Association of Home Builders, the average U.S. roof size is 2,647 square feet, and these roofs shed water quickly. Walls cannot do this. Roofing felt is not UV-resistant enough for exposed wall use.

Better Materials for Walls

Use house wrap or weather barrier fabric on walls instead. These products are made for vertical surfaces. They let water drain down and out. They also resist UV damage and wind better than roofing felt.

MaterialBest UseLifespan
Roofing FeltUnder roof shingles20-30 years
House WrapOn exterior walls20-40 years
Weather BarrierOn exterior walls25-50 years

When You Might Use Roofing Felt on Walls

In rare cases, you might use roofing felt on a wall for temporary protection. For example, during a roof repair, felt might cover a wall opening for a few days. But this is not permanent.

According to the U.S. Bureau of Labor Statistics, approximately 135,140 roofers work in the U.S., and professional roofers recommend using proper house wrap on walls, not roofing felt. For any permanent wall protection, use materials designed for walls. Your walls will last longer and stay free of water damage.

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