Windsor and Maidenhead · England
Clewer Window Mastic
We cover Clewer for mastic around window and door frames, sills and patio doors. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Old mastic that has gone black or come away
- Cracked sealant at the sill ends
- Cold air getting in at the frame edge
How we handle window mastic in Clewer
Around Clewer we seal all kinds of frames: uPVC, aluminium, timber and composite, plus patio doors, French doors and sills. The sealant is chosen to suit the frame material and the wall. If you have damp patches on the reveal after heavy rain and leaking joints at the ends of sills, we can put it right, on patio & French doors, window sills and uPVC windows alike.
Houses in smaller places like Clewer can stand more in the open than those in a built-up town, so exposed windows and doors face the weather head on. That’s hard on the mastic around frames and sills.
We stand behind the work with a one-year guarantee, so you are not left on your own once the job is done.
- Where
- Clewer (SL4)
- Region
- Windsor and Maidenhead
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Keep drainage slots and sill grooves clear
- Check the mastic once a year
- Do not use solvent cleaners on the joint
- Use gentle cleaners on frames and sealant
Try not to touch the new joint while it cures, following the cure time we give you. Keep jet washers away from the frames.
Wet, windy weather is when failed mastic shows itself, but resealing works best in dry conditions. Sorting cracked mastic early means the joint is sound before the bad weather.
What we are called out for in Clewer
Every frame moves through the day. Sun on a frame makes it expand, and it contracts again overnight, while the brick or render around it hardly moves. If the sealant can’t stretch, it splits.
Most people get in touch after spotting something like this:
- Sealant in the wrong colour for the frame
- Water coming in at the bottom corners of a door
- Gaps between the frame and the inside reveal
- Gaps left after new windows were fitted
Homes close to Church of St Andrew include some older properties, and the joint between an old wall and a newer frame is normally the first place rain gets in.
Comparing quotes
- The length of the guarantee
- How much experience the applicator has
- Is the old sealant removed completely?
- What the quote includes, VAT included or not
What affects the cost of window mastic
We don’t publish a price list, because jobs vary so much. The quote depends on:
- How easy the joints are to reach
- Whether there’s mould to deal with
- Whether old sealant or filler has to be cut out
- Working hours on commercial sites
Combining jobs into one visit generally makes better use of the time than several visits. We will give you a clear price for the lot.
Helping us quote
Photos help, but a description is a good start. Please mention:
- A few pictures by email, if you can
- How we’d reach the joints
- Where the job is, and your postcode
- The rough size of the job
We do not publish a price list. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or email us.
How it works
On the day, we look over the joints with you first. We protect the surfaces around the joints before any work begins. Most jobs take anything from an hour or two to a full day, depending on how many frames there are. For a job in Clewer, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- We clear up and check every joint is fully closed.
Before we arrive
- Let us know about parking restrictions
- Let us know about earlier repairs to the joints
- Clear items away from the joints we’re working on
Get a quote
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. Whenever you’re ready, call 0345 464 0079 or drop us an email.
Related advice
Landlord and commercial work in Clewer
We regularly work with letting and managing agents. Tell us the address, the job and how access works.
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
More services for Clewer
Elsewhere in Windsor and Maidenhead
Window Mastic in all 57 places in Windsor and Maidenhead
Our services in Windsor and Maidenhead
Areas we cover
More about window & door mastic
Window mastic in Clewer: local notes
With historic houses such as Windsor Castle (about 1 mile east) nearby, there’s older building stock in the area around Clewer as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Letting a property close to Windsor & Eton Central station? Then sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For site and facilities teams at buildings such as St Edward's Catholic First School, the mastic around its windows and doors needs looking after like any other building’s.
Clewer is about 1 mile north of Windsor, in Windsor and Maidenhead. Clewer gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our Windsor and Maidenhead coverage runs to 57 places, and Clewer is one of them. There’s also a page for Reading, about 15 miles away.
Postcode districts we cover here for window mastic: SL4. If you need window mastic at a property on Oak Lane, Vale Road and Mill Lane or a nearby road, we can help. You will find Clewer on the A308 and A332, so it’s easy for us to get to with everything needed for window mastic. If you’re just outside Clewer, we cover Windsor (1 mile south), Eton (1 mile north-east), Eton Wick (1 mile north-west), Boveney (1 mile west) and Dedworth (1 mile south-west). Larger places within reach include Maidenhead (5 miles north-west), Boyn Hill (5 miles west), North Ascot (5 miles south-west), Cookham (7 miles north-west), Furze Platt (6 miles north-west) and Broomhall (6 miles south).
What’s near Clewer
Typical jobs here are in homes near The Windsor Boys' School, The Windsor Boys' School and The Vansittart Arms, among other places. For rail, the closest station is Windsor & Eton Central station, roughly 0.7 miles east of the centre. Well-known places in the area include Museum of Antiquities (0.7 miles north-east) and King Edward VII Hospital (1 mile south-east). For a walk, there’s Taplow Lake and Bray Pit.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
Common questions in Clewer
Can you do window mastic in Clewer?
Yes. Our work covers London and the South East, and Clewer is part of that. You can phone 0345 464 0079 or send us an email and let us know what needs doing, and we’ll send you a clear quote.
Do you work for landlords with property near Windsor & Eton Central station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
When is the sealant fully cured?
That depends on the sealant used, so please follow the time we give you.
Is the work guaranteed?
Yes. All our work carries a 12-month guarantee, and we are ARBOMaster approved applicators.
Can I do it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Can you do the inside joint as well?
Yes. Plenty of draughts come through the inside joint as well as the outside, so it can be worth sealing both.
Is it OK to seal over old sealant?
No, because it fails. The old sealant always comes out first.
Do the sealants smell?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
Honest limits
Before booking, it’s worth knowing the limits too:
- Broken hinges, locks or handles
- Damp coming through the wall itself rather than the frame joint
- A frame that has rotted at the joint
If you are not sure, just phone 0345 464 0079 or email us and we’ll give you a straight answer.
What we seal
- Window sills
- Timber windows & doors
- Patio & French doors
- Aluminium frames
- uPVC windows
- Composite doors