A flat roof that drains,seals and stays sealedthrough Hampshire winters

Most of the failed flat roofs we replace in Havant and Portsmouth are old three-layer felt on extensions, garages, dormers and bays. Felt of that generation goes brittle, blisters in summer and splits along the seams, and once a split opens the deck beneath starts absorbing water. Because the water spreads sideways under the covering, the damp patch inside is often nowhere near the split.

The second failure is standing water. Where a roof was laid without adequate fall, or where the deck has sagged between joists, water sits after every shower. Ponding accelerates the breakdown of any covering, forces water into laps and joints, and adds weight to a structure that was not designed for it. We correct falls with firring or a tapered build-up rather than laying a new covering over the same puddle.

We strip back to the deck so we can see what we are covering. Soft, delaminated or rotten boarding is replaced, the fall is checked and corrected, insulation is specified where the space below is heated, then the new covering is installed with properly formed upstands, drips, trims and outlets. Edges and junctions are where flat roofs leak, so that is where the time goes.

You get photographs of the stripped deck before it disappears under the new covering, so you can see exactly what you paid for. The price is fixed in writing before we start, and nothing is added without your agreement.

The deck rots out

Chipboard and ply absorb water and lose strength. A roof that could have been re-covered becomes a re-deck, and a soft deck is genuinely unsafe to walk on for inspection or maintenance.

Damage reaches the room below

Extension and dormer roofs sit directly over living space. Water gets into plasterboard, insulation, cornice and decoration, and in dormers it runs down inside the wall build-up before anyone sees it.

Ponding compounds every fault

Standing water works its way into every lap and joint, freezes and expands in winter, and adds weight to a deck that is already weakening. Each shower makes the next failure more likely.

High-performance felt systems

Modern torch-on and self-adhesive membrane systems bear little resemblance to the brittle felt they replace. Laid in layers with fully sealed laps, correctly formed upstands and mineral cap sheets, they handle movement well, are economical over larger areas and are straightforward to repair locally in future if something is ever damaged.

Single-ply and rubber membranes

Single-ply and rubber systems suit garages, extensions and outbuildings where a large area can be covered with very few joints. Fewer seams means fewer potential failure points, and the sheets are dimensionally stable across the temperature swings a south-facing roof sees between a January night and an August afternoon.

Liquid-applied systems

Liquid coatings are the right answer on complicated roofs — plenty of pipes, upstands, rooflights or awkward junctions — because they seal around obstacles without needing a joint. They depend entirely on a clean, sound, correctly prepared substrate, which is why we strip and repair rather than coating over failing material.

Decks and structure

Plywood, OSB and older chipboard decks all behave differently once wet. We check firmness across the whole roof, not just at the leak, and replace what has softened. Where joists have sagged, correcting the fall with firring pieces is the difference between a roof that drains and one that ponds again in six months.

Insulation and warm roofs

Where the space below is heated, a warm-roof build-up places rigid insulation above the deck and beneath the covering, keeping the structure warm and dry and preventing interstitial condensation. Cold-roof construction still exists on older extensions and relies on ventilation instead. We specify to suit the building and explain which you have.

Upstands, trims and outlets

Upstands need adequate height where the roof meets a wall, a door threshold or a dormer cheek. Drip trims throw water clear of the fascia. Outlets and rainwater connections must be sized and positioned at the low point. These are unglamorous details, and they are the ones that decide whether the roof leaks.

Green roofs, balconies and walkways

Roofs that get walked on, hold planting or serve as a balcony need a covering rated for traffic or load, plus protection layers. Tell us how the roof will be used and it gets specified for that, rather than being covered with the same build-up as an unvisited garage.

Residential and commercial flat roofing

Domestic flat roofs are typically extensions, garages, dormers, porches and bays. Commercial flat roofs are larger, often with plant, pipework and multiple outlets, and usually need phasing so the building stays weathertight and open while the work runs. Both get the same fixed-price approach.

S&S Roofing & Building Limited

13 Braishfield Rd, Havant, Hampshire PO9 2HS, UK

Open 24 hours, 7 days a week