Flat Roof Over Garage: Your Replacement Options

Flat roofs over garages take a lot of abuse — UV exposure, temperature extremes, and foot traffic from cleaning gutters. When the existing felt starts to fail, it's a chance to upgrade to a system that will last a generation.

Option 1: Like-for-Like Felt Replacement

Replacing felt with a new 3-layer mineral felt system is the cheapest option. However, for a garage roof, a modern high-performance felt will last 15–20 years. This is a reasonable choice if budget is very tight, but not our first recommendation.

Option 2: GRP Fibreglass

GRP fibreglass is our most recommended option for garage roofs. It's seamless, extremely durable, looks great, and comes with a 25-year guarantee from quality manufacturers. For most single garages, it's a very affordable upgrade.

Option 3: EPDM Rubber

EPDM is an excellent choice, particularly for garages with unusual shapes or very low pitches. It's flexible and handles minor structural movement well. The large sheet sizes mean minimal joins — and joins are where leaks start.

Access and Disruption

Replacing a garage flat roof is usually a one-day job for a team of two. The garage needs to be cleared of valuables in case of debris during strip-out. You'll need to park your car on the road for the day. Most homeowners find it a very straightforward project.