If your lead roof is leaking or cracking, or someone has already had some of the lead nicked off it, you are probably wondering what to do next. A lot of folks just go for like for like lead because it feels like the proper job, particularly on older garages and extensions. But let's be straight with each other: lead is expensive, heavy, and it's got a target on its back these days. Plenty of folks are quietly looking for a better way. That's where fibreglass roofing (or GRP as most of us call it) comes in as a proper lead roof alternative. Done right, it gives you the traditional appearance, serious durability in British weather, and none of the theft headaches or eye-watering bills. We've been supplying GRP kits and trims to DIYers and small trades across the UK from our place in Paignton, Devon for years, and we see this switch all the time. The real problems with traditional lead roofs right now Lead has been the go-to for flashings and flat areas for generations, and a well-laid lead roof can last decades. But these days it's got some serious downsides: Cost - Replacing lead is rarely cheap. Material prices fluctuate, and you usually need a specialist to fit it properly. For a typical garage or extension roof, you're often looking at serious money. Theft risk - Lead theft is still a thing in the UK, particularly on accessible roofs. Churches and old buildings tend to get hit the hardest, but garages, outbuildings and extensions aren't safe either. When the lead disappears you're left with a mess and another expensive job on your hands. Weight & movement - Lead is heavy. It expands and contracts with our temperature swings (we get proper swings here in the UK), which can lead to cracking, especially if the roof structure moves even a bit. Maintenance - Maintenance is another headache. It must be checked from time to time, and occasionally re-dressed. It doesn't take much, but it's a task you don't have to do. If you think that's you, you're not the only one. We have customers call us weekly who are in the same situation. Why fibreglass (GRP) makes a genuinely good alternative GRP isn't trying to be lead, it's its own thing, and in a lot of situations it's the more practical choice: Lightweight but tough - Much easier on the roof structure than lead. Our marine-grade resins and matting are built to handle UK weather, including the expansion and contraction that causes headaches with other materials. No scrap value for thieves - Once it's down and finished, it's just not worth nicking. Peace of mind, especially if your roof is visible or accessible. Long lifespan with low maintenance - A well-installed GRP roof will easily see you through 25-40+ years. Minimal fuss once it's on - no periodic re-dressing like lead. Cost effective - Especially if you're doing it yourself or using a local builder. Our bespoke kits mean you only buy what you need. Looks the part - This is the bit a lot of people worry about. With the right trims and finish, it can look very close to traditional lead. We've got customers who’ve used it on everything from 1930s garages to modern extensions and even some heritage-style projects where planning wanted the traditional appearance without the traditional price tag. Getting the authentic lead look with simulated lead trims This is where a lot of the magic happens. Our C100 / C150 Simulated Lead Flashing Trims (and the matching C7 internal/external corners) are heavy-duty fibreglass, pre-formed, and designed to sit perfectly with GRP systems. They give you that classic lead appearance without the weight, cost, or theft risk. They work brilliantly with our full roofing kits and are straightforward to fit, no messing about shaping real lead on site. A lot of our customers buy them because they want a classic look without spending a lot of money. Check out the C100/C150 Simulated Lead Flashing Trims here, and have a browse of the full trims range while you're there. Rough cost comparison (UK 2026 ballpark) The price will depend upon the size of the roof and accessibility. This is also subject to the type of work you are doing, or whether you are having someone else do it. But to give you a rough idea... Traditional lead replacement: Going for traditional lead is usually the most expensive route, especially once you get past a small bay. GRP fibreglass (material + topcoat + trims via kit): Significantly lower, particularly when you use our bespoke kits. Full professional GRP install: Competitive with lead and usually faster. For a typical 10-15m² garage or extension roof, going the GRP kit route can save you a proper chunk compared with like-for-like lead, and you get something lighter and lower-maintenance. Our kit calculator on the homepage takes your measurements and works out exactly what you need (resin, matting, topcoat, trims, the lot). Worth using even if you're just pricing it up. How GRP handles real British weather We get asked this one quite a lot. Will GRP actually cope with the temperature swings and movement we get in the UK? Yeah, it can, but only if it's done properly. That's exactly why we go on so much about good preparation, decent matting, and making sure the bandage work around the trims and joins is solid. We've written a full guide on preventing GRP roof cracks and blistering from thermal expansion, well worth a read if you're in an area with big day/night or seasonal temperature changes. Read our guide on thermal expansion and GRP roofs here DIY-friendly or pro install? Both work A lot of our customers fit these themselves, especially on garages, sheds, and extensions. Our kits come with clear instructions, and we've got proper step-by-step video tutorials covering everything from cutting and fitting trims to laminating and applying topcoat. Watch our full set of fibreglass roof video tutorials here, the trim and bandage videos are particularly useful if you're matching simulated lead details. If you'd rather a pro does it, most decent flat roofers are happy working with GRP these days. We supply plenty of trades who use our kits regularly. Quick FAQs about lead roof alternatives Is fibreglass as good as lead? In many ways it's better for flat roof applications, lighter, no theft appeal, lower maintenance. A top-quality lead roof is still fantastic where it's the right material, but for most domestic flat roofs GRP is the more sensible modern choice. How long does a GRP roof last? 25-40+ years is realistic with a good install and quality materials. Some of the earliest GRP roofs are still going strong decades later. Will it look cheap? Not if you use decent simulated lead trims and finish it properly. From a distance most people can’t really tell the difference, and even close up it looks pretty convincing once the topcoat is on. Do I need planning permission? If you're simply replacing what you've lost in the same way, then for the most part you don't require planning permission. If it's listed or you live in a conservation area, it is advisable to call your local council to check anyway. Can I overlay an existing lead roof? Sometimes, but we generally recommend removing the old covering and starting fresh for the best long-term result. We can advise on your specific situation. Ready to move forward? If you're looking at a lead roof alternative, fibreglass is well worth considering. It's practical, cost-effective, and with the right trims it looks the part. Fancy seeing what a proper kit would cost for your roof? Head to the homepage and use our GRP & EPDM Roof Kit Calculator, it does all the hard work for you. Or if you want that classic lead appearance without the downsides, take a look at our simulated lead trims, they pair perfectly with our kits. Got questions about your specific roof? Give us a call at 0800 612 7903, we're a proper family-run business down in Paignton and we're happy to talk it through. No hard sell, just honest advice from people who actually use this stuff. Shop our full range of GRP roofing kits here.
