If you’re replacing a garage or extension roof, you want to know it will keep the rain out through winter. EPDM rubber roofing is suitable for that job, but the finished roof depends on more than the sheet you buy. The edges, drainage and surface underneath all need to be right. Heavy rain, snow and strong winds put different demands on a roof. Here’s what to expect from EPDM, what deserves a closer look and when a repair may be enough. Weather What matters on the roof What to check Heavy rain Drainage and watertight junctions Gutters, outlets and wall connections Frost and snow Snow loading and meltwater drainage Blocked outlets and signs of sagging Strong winds Secure attachment and impact damage Edges, trims and fallen debris How does EPDM roofing cope with heavy rain? EPDM is a synthetic rubber membrane that forms the waterproof covering over a roof. Many smaller roofs can be covered with one sheet, reducing the number of joints across the main surface. There are still details to finish around the edges, walls, rooflights and pipes. Rain shouldn’t pass through an intact, correctly installed covering. If a leak appears, those connections need checking as well as the membrane itself. Buying a good sheet won’t make up for an unfinished wall junction. What if water stays on the roof? A puddle doesn’t, by itself, prove that the membrane is leaking. It does give you a reason to look at how the roof drains, particularly if water repeatedly collects in the same place. A flat roof still needs a fall towards its drainage point. Leaves in a gutter are one possible cause of poor drainage, a dip in the roof is another. Clearing a blockage won’t correct the roof levels. If water keeps collecting after the gutter is clear, ask a roofer to investigate. Can snow and frost damage a rubber roof? Cold weather alone doesn’t mean a rubber roof will split. EPDM is flexible, and our ClassicBond garage roof kits are intended to cope with hot and cold weather. That doesn’t tell you how much snow the building can carry, though. The roof structure has to support the snow. The membrane keeps water out, it cannot strengthen weak boards or joists. There isn’t one safe snow depth that applies to every garage or extension. Don’t climb onto an icy roof or try to scrape snow off with a shovel. If the roof starts sagging, makes unusual creaking sounds or you’re concerned about a heavy build-up, keep people out of the affected area and seek professional advice promptly. Once snow thaws, the water needs a clear way off the roof. Arrange gutter and outlet maintenance before winter, while access conditions are safer. What happens to an EPDM roof in strong winds? Wind can pull upwards on a roof covering. This is called wind uplift, and resisting it depends on how the whole roofing system is attached. Adhesive, edge fixings and the condition of the supporting surface all matter. An exposed roof needs particular care when its fixing specification is chosen. Don’t assume that a kit suitable for one sheltered garage will suit every location without checking the installation requirements. Our garage kits include both deck adhesive and contact adhesive for the perimeter, along with edge trims. Those components have different jobs, follow the instructions for the actual system rather than treating the adhesives as interchangeable. Storm damage can also come from something hitting the roof. A sharp branch or other debris can puncture a membrane. Weather resistance doesn’t make EPDM damage-proof. If an edge starts lifting or flapping, arrange an inspection promptly instead of waiting for the next storm. What should you check after a storm? Wait until the weather has settled. Start indoors and at ground level, or look from a safe window if one overlooks the roof. You don’t need to climb up to spot every warning sign. Check ceilings and the inside of the garage for new damp patches or drips. Look for displaced trims, hanging guttering or visibly lifted edges. Note fallen branches or debris on the roof, without trying to retrieve them yourself. These observations help you explain the problem to a roofer. They won’t tell you exactly where water is getting in. What you notice What to do next A new leak or damp patch Arrange an inspection to find the entry point. An edge lifting or flapping Seek prompt help and keep clear of loose material. A branch or visible surface damage Have the covering checked for punctures. Water repeatedly collecting Ask for drainage and roof levels to be checked. For preparation around the rest of the property, the Met Office’s winter advice covers gutters and overhanging trees. Can a damaged EPDM roof be repaired? A small area of damage may be repairable with a compatible EPDM patch. The surface preparation and repair materials need to match the system, so don’t reach for a general-purpose sealant without checking suitability. The bigger question is what else needs attention. Ask the roofer whether the damage is localised, whether water has affected the deck and whether there’s a loose edge or drainage problem to put right. A patch alone won’t solve those issues. Take photographs from a safe position if you can. Note when you first saw the leak and whether it only happens during heavy rain. That gives the person inspecting the roof something useful to work from. Frequently asked questions Can EPDM roofing be installed in winter? It can be possible during a suitable weather window. The deck must be sound, clean and dry, and the adhesive’s application conditions must be met. Check the current product instructions before starting, a membrane’s ability to withstand winter weather is different from the conditions needed to install it. Does EPDM need a protective coating before winter? Don’t add one as a routine winter job. First check what the membrane manufacturer recommends. An unsuitable coating creates an extra problem rather than fixing poor drainage or a damaged detail. Does storm damage mean replacing the whole roof? Not necessarily. An inspection should establish the extent of the damage and the condition underneath before you decide between repair and replacement. Choosing materials for your roof Planning to replace your rubber roof? Browse our EPDM roofing kits and materials, or call us on 0161 672 7090 if you’re unsure what you need. We’ll help you work out what to order.
