Slough · England
External Mastic in Datchet
Professional external mastic in and around Datchet, with old sealant always removed completely.
- Cracked joints where brick meets render or frames
- Rigid filler in a joint that should flex
- Leaking joints around cladding and façade panels
About our external mastic in Datchet
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. If you are dealing with hard, crazed mastic that has stopped moving and sealant that has lost its bond to the brick or render, we can help, on brickwork movement joints, render & cladding joints and copings & trims alike.
Houses in smaller places like Datchet can stand more in the open than those in a built-up town, so exposed walls and rooflines take more wind-driven rain. That’s where gutter joints and wall joints tend to fail first.
A 12-month guarantee comes as standard, so you are covered after we’ve gone.
- Place
- Datchet (SL3)
- Region
- Slough
- Cover
- One year on every job
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What affects the quote in Datchet
The quote reflects the job in front of us. We look at:
- Access and height
- Mould in or behind the old joints
- The product the joint needs
- How many rooms, windows or areas are involved
The cost depends on the amount of work, how much old material has to come out and access to the work. We give a clear quote before we start.
Helping us quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- A few photos by email, if you can
- Any access issues, like height or stairs
- Whether it’s a home or a business
- What’s wrong with the joints now
We do not publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or email us.
Places near Datchet
What else we do in Datchet
Datchet buildings and the weather
Historic houses like Frogmore House (about 1 mile south-west) are a reminder that the area around Datchet has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Datchet St Mary's CofE Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. In the older streets around Church of St Mary, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Datchet is about 2 miles east of Windsor, in Slough. Every kind of property in Datchet is covered for external mastic, old or new, large or small. The work is guaranteed for a year. Across Slough, we cover 31 places, and Datchet is one of them. You can also see our page for Reading, roughly 17 miles from Datchet.
Jobs for external mastic in SL3 works the same way as everywhere else we cover. Whether your property is on High Street, London Road and Percy Place or anywhere close by, our applicators can take on the job. Neighbouring places we cover for external mastic include Ditton (1 mile north-east), Myrke (1 mile north-west), Sunnymeads (1 mile south-east), Brands Hill (2 miles east) and Old Windsor (2 miles south). Larger places within reach include Slough (3 miles north-west), Cippenham (3 miles north-west), Britwell (4 miles north-west), Burnham (5 miles north-west), Stoke Poges (4 miles north) and Huntercombe (4 miles north-west). Being one of Slough’s larger places, Datchet has every kind of property, from flats to offices.
Local landmarks in Datchet
Around Datchet, our work takes us to homes and buildings near St George's School, The Royal Stag pub and Home Park and the streets around them. There’s a railway station in Datchet itself: Datchet station. Nearby you’ll also find Museum of Eton Life (1.5 miles west) and Upton Hospital (1.7 miles north-west). The countryside around Datchet includes Staines Reservoirs.
FAQs for Datchet
Can you do external mastic in Datchet?
Yes, Datchet is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or send us an email and let us know what needs doing.
Do you cover smaller places like Datchet?
Yes, Datchet is covered. Our work covers London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Is there any odour?
Sometimes, a little. It fades as the sealant cures, and ventilation helps.
When is the sealant fully cured?
It depends on the product. Before we leave, we will tell you the cure time.
Do you use backing rod?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back so the bead can stretch.
Do you guarantee your work?
Yes. There’s a 12-month guarantee on every job, wherever you are.
Where is Mr Mastic based?
We’re based in Crawley, and we work across South East England, London and Scotland.
Can I do it myself?
You can, for simple jobs. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
What the job involves on each surface
Cladding and façade panels
Where a cladding system has its own specified sealant, we follow it. Send us any details you have about the façade.
Concrete and blockwork
Big joints in concrete need careful depth control. We size the backing rod to the gap and keep the sealant to the right depth.
How to look after the new joints
After the cure time, these simple habits help:
- Look over the joints every year, ideally after winter
- Never let anyone fill a movement joint with mortar
- Avoid pressure-washing directly into sealant joints
- Fix overflowing gutters above sealed joints
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
What we do, step by step
Every visit runs the same way: we check the joints, protect the area around them, carry out the job and tidy away. It generally takes anything from a few hours to several days, depending on the building. In a smaller place like Datchet, parking is seldom the issue; lanes, gates and long drives are worth mentioning. If the job is outside, tell us about side access and how high the joints are.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Tell us about any water getting in
- Clear the area around the work
- Tell us if parking is tricky
Ask for a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. Whenever you’re ready, ring 0345 464 0079 or drop us an email.
Advice
Why deal with it now?
Running new sealant over the old bead rarely lasts. The new layer cannot bond properly to old, weathered material, so the old joint is cut out fully first. In an older home around Datchet, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Why choose Mr Mastic in Datchet
- Sanitary silicone with an anti-fungal additive in wet areas
- Rated 4.9 stars on Google
- A 12-month guarantee on all work
- Domestic, commercial and hotel work
Common problems we fix in Datchet
Using the wrong sealant is another common reason. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, and it tears off the sides.
Common reasons people contact us include:
- Failed seals between different materials
- Moss and dirt in joints with no sealant left
- Weathered mastic that no longer stretches
- Sealant that has lost its bond to the brick or render
If you let a flat or house near Datchet station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
What your quote should include
- Whether you can choose the colour
- Is VAT in the price?
- What happens if they find a problem under the old sealant
- How long to leave it before use
When it is not the sealant
Some problems need a builder, plumber or other trade rather than us:
- Failed render or damaged cladding panels
- Cutting new joints into brickwork, which is building work rather than sealant work
- Structural movement, which needs a surveyor or engineer
If in doubt, call 0345 464 0079 or drop us an email and we’ll say what we think.
Where we work in Datchet
- Render & cladding joints
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Façade panels
- Concrete & block