Flat roofing in Macclesfield
Most flat roofs on Macclesfield homes are on extensions, dormers, garages and bay windows, and most leaks come from the edges and joints rather than the middle. We repair what can be repaired and, when the deck underneath has gone soft, replace the roof with GRP fibreglass, EPDM rubber or torch-on felt, whichever suits the roof.
Repair or replace a flat roof
A blister, a split at an upstand or a failed edge trim can usually be repaired. If the roof feels soft or spongy underfoot, water has got into the timber deck, and a patch on top will not stop it rotting. That roof needs stripping back to the joists and a new deck.
We lift a section where needed to check the deck before quoting, so the price is based on what is actually there.
Which flat roof system
There is no single best system. The choice depends on the shape of the roof, what will sit on it and how it is used:
- GRP fibreglass: a seamless resin and glass-fibre roof laid in one piece on a new deck. Good for roofs with awkward shapes and for walking on, such as a balcony.
- EPDM rubber: a single sheet of synthetic rubber bonded to the deck, with few or no joints. Quick to lay, flexible in cold weather and well suited to simple rectangular roofs.
- Torch-on felt: layers of reinforced bitumen membrane bonded with heat. A traditional, well-understood system, often used on larger or commercial roofs.
Warm roofs and condensation
Older flat roofs are usually cold roofs, with insulation between the joists and a ventilated gap above. Without enough ventilation, warm moist air from the house condenses on the underside of the deck and rots it from inside.
When we replace a flat roof we usually build it as a warm roof: insulation boards go on top of the deck, under the waterproof layer, so the timber stays warm and dry. It also raises the roof slightly, which we check against door thresholds, windows and flashings before we start.
Falls, outlets and edges
A flat roof is never truly flat. It needs a fall, a slight slope, so water runs off to a gutter or outlet instead of standing in pools. Ponding water is one of the main reasons flat roofs fail early, so a new roof is built with tapered firrings or tapered insulation to give it a proper fall.
Edges matter just as much: the drip trims at the gutter, the upstands where the roof meets a wall and the flashings over them are where most flat roof leaks start.
Signs your flat roof needs attention
- Puddles still standing a day or two after rain
- Blisters, cracks or splits in the felt
- A soft or springy feel when you walk on it
- Damp or mould on the ceiling below
- Lifting edges or trims, especially after high wind
- Moss and plant growth on the surface
Read before you decide
Flat roofing: questions people ask
How long does a flat roof last?
It depends on the system and how well it was laid. A properly installed GRP or EPDM roof on a sound deck lasts considerably longer than the older single-layer felt roofs that many homes still have. The deck, the falls and the detailing at the edges decide the real lifespan.
Can you put a new flat roof over the old one?
Sometimes, but we rarely recommend it. Overlaying traps any damp in the old deck and hides rot, and it adds weight. Stripping back lets us check the timber and build the roof properly.
Do I need planning permission for a new flat roof?
Replacing an existing flat roof like-for-like does not usually need planning permission, though it is building work that should meet the Building Regulations for insulation. Converting a flat roof to pitched, or adding a balcony or terrace, can need permission.
Can a flat roof take a roof garden or solar panels?
Often, but the structure must be checked for the extra weight and the waterproofing chosen to suit. GRP and some membranes are better for foot traffic. Tell us what you plan to put on the roof before we specify it.
Tell us what is happening with your roof
Call, or send a few details and a photo if you have one. We will come back to you, arrange a visit and give you a written quote before any work starts.