How Is a Flat-Roofed Garage Handled When Re-Roofing in St Mellons?

Walk around St Mellons and you will see plenty of flat-roofed garages, porches and single-storey extensions tacked on to the main house. Their roofs often get done last, or not at all, yet a failed flat roof can let water into a room just as readily as a pitched one. Here is how we deal with them when we are re-roofing the main house.

Start with why it is leaking

Flat roofs rarely fail all at once. Ponding water, blistered or split covering, open joints at the edges and failed seals around rooflights are the usual starting points. We look at the ceiling underneath, the fascia line and the junction with the house wall before deciding whether to repair patches or strip the lot.

Taking off the old covering

Older garage roofs are commonly built-up felt layered over timber boards, sometimes with several coverings laid on top of each other. Where it is possible we strip back to the deck so we can see what is below, because new waterproofing laid over damp boards only traps the problem. Boards that are soft, stained or sagging are cut out and replaced, and any rotten joist ends are dealt with before the new covering goes on.

• Soft or spongy boards that flex underfoot from the loft side
• Damp joist ends where the roof meets the wall
• Old felt layers that have blistered or lifted
• Sagging areas where water has pooled for years

Choosing a new covering

There are several sound systems for a garage roof, including modern fibre-reinforced single-ply membrane, liquid-applied coatings and traditional torch-on felt. Each suits different situations, and we explain which fits yours, depending on shape, access and how the roof will be used. Rooflights, vents and outlets are all noted before work begins.

Falls, edges and drainage

A flat roof needs a slight fall so water leaves it. On many estate garages the fall is poor, so we often add tapered boards or firring to move water to the gutter. Edge trims, drip details and a clean, working gutter matter just as much as the surface. Without them, the best membrane in the world will still end up with a puddle at one end.

Tying it in with the main roof

Where the garage meets the house, lead flashing or a proper upstand protects the join, and it is best done at the same visit as the main roof so the two are sealed to each other. Fascias and guttering get renewed along the same line for a tidy finish. Some changes may need planning or Building Regulations checks — we advise before work starts.

Why Choose T & T Roofing South Wales

We're new roof installation specialists covering South Wales, using premium tile and slate roofing systems and honest advice — not a generic call-out. Every job starts with a free quotation and guaranteed workmanship throughout.