Repair Sagging Roof in Lincolnshire & Cambridgeshire

As a family-run business with deep roots in the Spalding and Peterborough communities, our reputation is built on every single job we do. When you choose Foster and Son, you’re not just hiring a contractor; you’re partnering with a local team that genuinely cares about protecting your home and our good name.

Yes, a sagging roof is a serious structural problem that you should not ignore. While it may have developed slowly over many years, the sag is a clear sign that the roof's structure is under strain. The problem will only get worse over time and leaving it can lead to further damage, water ingress, and in the worst-case scenario, the risk of collapse. It's a problem that needs a professional assessment as soon as possible.

A roof can begin to sag for several reasons, and often it's a combination of factors. The most common cause is age; over decades, the timber rafters that support the roof can weaken. Water damage is another major culprit, as persistent leaks can rot the structural supports. Sometimes the problem is down to the original construction, with rafters that are too small or spaced too far apart for the weight they have to bear. We also see sagging caused by additional weight, for example, after replacing lightweight slates with much heavier concrete tiles without strengthening the support structure first.

Whether your roof can be repaired or needs to be replaced depends entirely on the cause and extent of the sag. If the problem is localised to a few weakened rafters, it may be possible to fix it by installing additional support timbers alongside the existing ones (a process called 'sistering'). However, if the sag is widespread, or if there is significant water damage and rot, a full roof replacement is often the only safe and effective solution. An inspection by a professional roofer is the only way to know for sure what your specific roof needs.

Fixing a sagging roof is a job for experienced professionals. The first step is always a thorough inspection to diagnose the root cause of the problem. If a repair is possible, it typically involves propping up the roof from inside the loft space to take the weight, then strengthening the weakened rafters with new timber. If a full replacement is the right course of action, the process will involve stripping the old roof, repairing or replacing the timber structure, and then installing a new roof covering. The time it takes can range from a couple of days for a straightforward repair to over a week for a full re-roof, depending on the size and complexity of the job.