Building an extension or replacing a worn garage roof leaves you with a decision that is easy to rush: which flat roof system to use. Felt, rubber and fibreglass all keep water out when properly laid, but they behave differently around corners, in cold weather and on tricky shapes. The deck, falls and edge details underneath count for as much as the top covering.
This guide compares the three common options for Lincolnshire homeowners, in plain terms. It looks at a Felt Flat Roof Installation, an EPDM Rubber Roof Installation and a GRP Fibreglass Roof Installation, then covers the practicalities of a Garage Flat Roof Installation and an Extension Flat Roof Installation. We avoid brand names, because the right system depends on your building and how you use it.
A waterproof layer cannot fix a poor base. The timber deck needs to be sound, dry and flat enough to carry the covering, with a gentle fall towards the outlet so water drains instead of ponding. Insulation, vapour control and ventilation are decided at this stage, especially for a warm roof over a heated room. Edges, trims and wall junctions are where leaks usually begin, so details matter more than the headline material. Any honest quote should describe the deck work, not only the membrane laid on top.
Modern built-up felt is laid in layers, bonded together, and is a familiar choice for garages and simple extensions. Its advantages are that it is well understood by most roofers, repairable in sections and suits irregular shapes. The drawbacks are that laps and upstands rely on skilled workmanship, and it is often applied with heat, which needs care near timber and in dry spells. Quality varies with the specification, so ask how many layers are proposed and how the edges are finished. Done well, felt gives dependable service at a sensible level of outlay.
An EPDM Rubber Roof Installation uses a large rubber sheet, often one piece for a whole roof, bonded to the deck. With few or no joins in the middle of the roof, it suits simple rectangular shapes well, and it copes with movement and cold weather. The weak points are the edges, corners and penetrations, where joints and adhesives are used, and the surface can be punctured by sharp objects or careless foot traffic. It is lightweight and clean to lay, with no naked flame involved. It tends to be less forgiving on awkward geometry or heavily detailed roofs.
A GRP Fibreglass Roof Installation forms a hard, seamless skin over boards, finished with a top coat. It is strong underfoot, handles odd shapes and small roofs well, and gives clean trims at the edges. The trade-offs are that it needs a sound, dry deck and decent weather to cure, and that a rigid skin can crack if the structure moves a lot. Colour and finish choices are wide. It is a popular option for small extensions, porches and dormer cheeks. Repairs are possible, though matching the finish takes care.
A Garage Flat Roof Installation is often about robustness and simplicity, with access, loft storage and falls to consider. An Extension Flat Roof Installation brings insulation, rooflights, a tie-in to the main roof and the abutment flashing into play. Those details, plus the size and shape of the roof, the existing deck condition, access and whether scaffolding is needed all affect the quote. If a Velux-style roof window or lantern is planned, say so early. Weather also governs scheduling, so we avoid promising dates until we have seen the job.
We are based in Beckingham near Lincoln and cover Lincolnshire, including Lincoln, Grantham and Spalding. To get a free quotation, tell us whether it is a new build, an extension or a garage replacement, give rough dimensions, and say whether you want rooflights or insulation upgrades. Planning drawings, if you have them, are helpful. We will usually visit to look at the structure, discuss the options in plain language and explain why we would suggest one system over another. There is no pressure to decide on the day.
For new flat roof systems for extensions and garages anywhere in Lincolnshire, call or WhatsApp 07561 405402, or use the form below and tell us about the job.
Pictures are for illustration purposes only.
See all New Roof Installations services in Lincolnshire →
There is no single answer, as it depends on the shape, the deck and how the roof will be used. Felt, rubber and fibreglass all work on garages when laid properly. We can talk through your roof and explain which we would lean towards and why.
If the room below is heated, building requirements and comfort both point to insulation, and the build-up needs designing so moisture does not get trapped. Your builder or designer may already have specified it. We can advise on how the covering fits with that.
Sometimes, but cold, damp or frosty conditions can affect adhesives, curing and heat-laid products. A good roofer will wait for a suitable spell rather than risk a poor result. Dates depend on conditions and the type of system chosen.
Tell us about the job and we will be in touch.
Prefer to talk? Call 07561 405402 or WhatsApp us.
