Rotten Sill Replacement

Rotten Sash Window sill Replacement in Eastbourne and throughout East Sussex

A rotten window cill does not always mean the whole sash window has to be replaced.

In many older timber sash windows, the cill is the part that suffers most from weather, standing water, and failed paintwork. The rest of the window may still be sound.

At RWJ Sear Restorative Carpentry, I repair and replace rotten timber cills on sash windows in Eastbourne and across East Sussex, using proper timber repair methods wherever possible.

The Problem

The cill is one of the hardest-working parts of a sash window.

It sits at the bottom of the window and takes the worst of the weather. Rainwater runs down the glass, over the lower sash, and onto the cill. If the paintwork fails, water gets into the timber and rot begins.

Once a cill starts to rot, it can become soft, cracked, hollow, or crumbly. In bad cases, the front edge may break away completely.

Many people are told that the entire window needs replacing. Often, that is not necessary.

A rotten cill can often be repaired or replaced while keeping the original sash window and box frame.

Common Signs of a Rotten Window Cill

You may need this repair if:

• The timber cill feels soft

• The front edge of the cill is breaking away

• Paint is blistering, flaking, or peeling

• The cill has cracks or open joints

• Water is sitting on the cill

• The cill looks hollow, sunken, or uneven

• Filler repairs are falling out

• The lower part of the frame is damp or rotten

• The lower sash sticks or will not close properly

• You can push a screwdriver into the timber

• The outside of the window looks tired or decayed

Rotten cills should not be ignored.
Once water gets in, the damage can spread into the lower frame, pulley stile, linings, and surrounding timber.

Why Timber Window Cills Rot

Window cills usually rot because water has been allowed to sit in or enter the timber.

Common causes include:

• Failed paintwork

• Poor previous filler repairs

• Open joints

• Cracked sealant

• Water sitting on a flat or damaged cill

• Lack of proper drip detail underneath the cill

• Damp masonry around the window

• Poor drainage

• Lack of maintenance over many years

• Modern materials trapping moisture in old timber

The cause matters. There is no point hiding the rot with filler if water can still get in.

What I Do

I inspect the rotten cill and the surrounding sash window frame to see how far the damage has spread.

Depending on the condition of the window, the work may include:

• Cutting out the rotten cill

• Cleaning back to sound timber

• Removing failed filler repairs

• Making a new timber cill section

• Splicing in new timber where needed

• Repairing the lower frame

• Repairing rotten corners

• Checking the lower sash

• Checking for water traps

• Making sure the repair sheds water properly

• Preparing the repair for painting

• Keeping as much original timber as possible

The aim is to remove the rotten timber, rebuild the damaged area properly, and keep the original sash window in service.

Repair, Not Replacement

A rotten cill does not usually mean the window is finished.

Older sash windows were made to be repaired. In many cases, the cill or part of the cill can be replaced without removing the whole window and without replacing the original sash.

This is often the best approach for period homes, Victorian houses, Edwardian houses, Georgian properties, listed buildings, and conservation areas.

Replacing only the damaged timber keeps the character of the window and avoids unnecessary waste.

Proper Timber Cill Repairs

A proper cill repair is not just a smear of filler over soft timber.

Rotten wood has to be cut out. The remaining timber has to be sound. New timber has to be shaped and fitted correctly so the window is strong again and water can run away as it should.

A good repair should look right, work properly, and give the window many more years of life.

Areas Covered

I repair and replace rotten sash window cills in:

Eastbourne, Meads, Old Town, Motcombe, Willingdon, Hampden Park, Polegate, Pevensey, Westham, Hailsham, Seaford, Lewes, Bexhill, Hastings, and other parts of East Sussex.

If you are unsure whether I cover your area, please get in touch.

Contact RWJ Sear

If your sash window cill is rotten, soft, cracked, breaking away, or full of failed filler, I may be able to repair it without replacing the whole window.

Contact RWJ Sear Restorative Carpentry for rotten sash window cill repair and replacement in Eastbourne and all over East Sussex.

Phone:07930 335 937

Email: jim@rwjsear.com

Website: https://www.rwjsear.com

Rotten Cill Replacement — Eastbourne and East Sussex

RWJ Sear Restorative Carpentry
Traditional sash window repairs
Rotten cills repaired or replaced properly
Repair before replacement wherever possible