Rotten Sill Repair in Borehamwood , Hertfordshire

Sills usually rot because of "ponding," where water sits on the flat surface rather than running off. If the paint develops even a tiny hairline crack, moisture gets trapped against the timber. In many London properties, previous repairs may have used poor-quality softwoods or standard fillers that trap moisture rather than sealing it out. We use durable timbers like Accoya and specialist resins to prevent this cycle of decay.

In the vast majority of cases, yes. As long as the upper parts of the box frame are structurally sound, we can perform a sill splice. This involves removing the bottom 6 to 10 inches of the frame and the entire sill, then fitting new timber. It is a much more cost-effective and less intrusive way to maintain your period home compared to a full replacement.

We prefer to use Accoya or high-quality seasoned hardwood for sill replacements. Accoya is particularly effective for properties in areas like Westminster or Richmond because it is incredibly stable and does not rot. We finish the repair with traditional putty lines and professional-grade primers to ensure the new timber is fully weather-proofed before we leave the site.

A rotten sill often creates gaps where the bottom rail of the sash meets the frame, letting in cold air and noise from busy South West London roads. While we are repairing the sill, we can also install our draught-proofing system. This involves machining hidden brush seals into the beads, which closes the gaps and makes your Victorian or Georgian home much quieter and warmer.

General repairs and timber splicing are usually considered "like-for-like" maintenance and do not typically require planning permission, even in strict Article 4 areas of Wandsworth or Lambeth. However, if you are looking to upgrade to double glazing at the same time, Charlie Burgess can advise you on local heritage requirements to make sure your windows remain compliant with conservation guidelines.