Windsor and Maidenhead · England
Window & door mastic in Sunningdale, Windsor and Maidenhead
Professional window mastic in and around Sunningdale, with old sealant always removed completely and a one-year guarantee.
- Damp patches on the reveal after heavy rain
- Gaps between the frame and the inside reveal
- Old mastic that has gone black or come away
What sealant work can’t fix
We’d rather tell you now than do work that will not last, so these are the limits:
- Damp coming through the wall itself rather than the frame joint
- Broken hinges, locks or handles
- Worn gaskets, brush seals or a door that has dropped
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
Where we work in Sunningdale
- Patio & French doors
- Timber windows & doors
- Composite doors
- uPVC windows
- Aluminium frames
- Window sills
Window mastic in Sunningdale
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. Typical jobs include gaps left after new windows were fitted and cracked or shrunken mastic around the frame, across window sills, aluminium frames and patio & French doors.
Homes around Sunningdale range from older properties to newer houses, and their windows range just as widely. The right sealant depends on the frame and on what it sits in.
Each job carries a 12-month guarantee, whatever its size.
- Location
- Sunningdale (SL5)
- Wider area
- Windsor and Maidenhead
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Places near Sunningdale
More services for Sunningdale
Keeping the joints in good condition
To keep the joints looking good and working properly:
- Ventilate rooms so frames don’t stay wet inside
- Keep drainage slots and sill grooves clear
- Avoid blasting the frames with a pressure washer
- Keep paint off silicone joints
Timber frames need their paint kept up, since wood that gets wet swells and shrinks more. Paint up to the joint, not over the silicone.
Water gets in quietly when mastic fails. You might not see it until plaster blows or a damp patch appears inside. Early resealing stops it reaching that point.
Sunningdale homes and the weather
With historic houses such as St Leonard's Hill (about 4.8 miles north) nearby, there’s older building stock in the area around Sunningdale as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. 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.
If you look after a building such as Holy Trinity CofE Primary School, larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as Holy Trinity Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Letting a property close to Sunningdale station? Then sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Sunningdale is about 4 miles south-west of Egham, in Windsor and Maidenhead. For window mastic in and around Sunningdale, it’s easy to get a quote: please call 0345 464 0079 or send us an email. We’re based in Crawley and cover Windsor and Maidenhead, Sunningdale included. We cover 57 towns and villages across Windsor and Maidenhead, large and small. We also work in Reading, about 15 miles from Sunningdale.
Postcode districts we cover here for window mastic: SL5. If you need window mastic at a property on Station Road, High Street and Church Road or anywhere close by, we can help. Main roads around Sunningdale include the B383, which makes travel easy. If you are just outside Sunningdale, we cover Broomhall (1 mile south-east), South Ascot (1 mile west), Brick Hill (2 miles south), Windlesham (2 miles south) and Chobham (4 miles south-east). Larger places within reach include Maidenhead (9 miles north-west), Windsor (5 miles north), Boyn Hill (9 miles north-west), North Ascot (3 miles north-west), Cookham (12 miles north) and Furze Platt (10 miles north-west).
What’s near Sunningdale
In Sunningdale, that means homes and buildings near Sunningdale School, Charters School and Silwood Park, among other places. The nearest railway station is Sunningdale station, about 0.5 miles south. A little further out are Heatherwood Hospital (2.3 miles west) and Chobham Museum (3.9 miles south). For a walk, there’s Virginia Water Lake and Gracious Pond.
DIY sealant or a professional job?
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
What affects the cost of window mastic
You’ll get a clear quote before work begins. It takes into account:
- The product the joint needs
- The size of the job
- Whether the work is at height
- The number of rooms or windows
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. You will know the price before we begin.
Helping us quote
Photos help, but a description is a good start. Please mention:
- Where the job is, and your postcode
- Photos by email, if that is easy
- Whether it has been sealed before
- What’s wrong with the joints now
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Landlords, agents and businesses in Sunningdale
Letting agents often deal with us directly. Tell us the address, the job and how access works.
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
How it works
On the day, there’s very little for you to do. Point us to the joints and we’ll get on with it. The job generally takes a few hours for a handful of frames, longer for a whole house. Parking around Sunningdale is normally easier than in a town centre, but mention any lanes, gates or long drives. For outside work, side access and the height of the joints help us plan.
- First we look at every frame and agree the list.
- We remove the old mastic and clean the frame and the wall.
- 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.
Getting ready for the visit
- Tell us about any water getting in
- Let us know about earlier repairs to the joints
- For indoor joints, keep the area dry beforehand if you can
Getting a quote
Need a quote? Please phone 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear price before we start.
Related advice
Surface by surface
Window sills
Every drop off the glass ends up on the sill, so the sill ends and the joint under the frame are vital. They’re cut out and resealed with exterior sealant.
Timber windows & doors
Soft or rotten wood cannot be sealed successfully. If we find rot, we’ll tell you before going ahead, as that is a job for a joiner.
Common questions in Sunningdale
Can you help a landlord with a rental near Sunningdale station?
Yes. We work for landlords and agents as well as homeowners, and several properties can be quoted together. You can call 0345 464 0079 or drop us an email with the details for a clear quote.
Is Sunningdale within the area you cover?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
When is the sealant fully cured?
Many sealants skin over quickly but take longer to cure fully. We will give you the cure time for the product we used before we leave.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before applying anything new.
Will there be a smell?
That depends on the sealant. Some smell for a while, some hardly at all.
Which products do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we will explain our choice.
Can you get sealant to suit coloured frames?
Yes. Grey and black frames get grey or black sealant, and wood-effect frames normally suit brown.