Garage, extension & dormer flat roofs

Small roofs are not small jobs. A garage roof has the same number of junctions, upstands and outlets as a house, in a quarter of the area — which is why the price per square metre looks higher, and why cheap small-roof work so often disappoints. We price them properly, not quickly.

Garage roofs

Garage roofs sit in the worst spot: unheated, poorly ventilated, and often carrying the condensation that comes off a car and a tumble dryer. That trapped moisture attacks a flat covering from underneath, which is why so many garage roofs blister and fail long before their time.

Where we are replacing one, we deal with the ventilation at the same time rather than just laying a new membrane over the problem. Most garage roofs are a one or two-day job, and the majority fall between £900 and £2,000 including strip-out, new decking where needed and the finished system.

If the garage is being converted to living space, the specification changes — extra insulation, vapour control, and usually a warmer roof build-up. Tell us that at survey stage and we will price it correctly rather than revisiting it later.

Extensions, dormers and orangeries

Extension roofs are where detailing earns its money. There is nearly always a junction with the existing house wall, one or more rooflights, and a fascia or parapet line that has to look deliberate as well as work.

We install rooflights and upstands as part of the roof package, dress the membrane into the abutment with proper flashing rather than mastic, and finish the perimeter with drip trims and fascia that match the rest of the property. Where an extension roof meets an existing tiled roof, we form a proper lead-lined or GRP valley rather than relying on overlapping materials.

On many extension projects we are working alongside other trades. We are used to sequencing around builders and will liaise directly with your main contractor so the roof goes on at the right point, not the convenient one.

Outbuildings, garden rooms and ancillary roofs

Garden offices, workshops, orangeries, porches, bay windows and balcony decks all use the same principles at a smaller scale. For garden rooms and workshops that will be used year-round, we normally recommend a liquid system: it handles the smaller dimensions and the tighter junctions better than a sheet material, and it does not need the fixings that would otherwise puncture the covering.

For bay windows, porches and small canopies, a two-layer high-performance felt system is usually the sensible, economical choice. We will happily quote both and let you decide with the numbers in front of you.