Windsor and Maidenhead · England
External & façade joints in Cold Harbour, Windsor and Maidenhead
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Cold Harbour and across Windsor and Maidenhead. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Joints with sealant missing in places
- Cracked joints where brick meets render or frames
- Hard, crazed mastic that has stopped moving
How the visit works
There’s no need to move everything out, just the space around the work. Everything nearby is protected, and the job takes a few hours to a few days, depending on the length of joint and the access for a typical job. In a small place like Cold Harbour, access is normally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Tell us about access, such as stairs, a lift or high-level joints
- Move anything stored near the joints
- Let us know about parking restrictions
How to 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’ll explain how we’d tackle it. Whenever you are ready, phone 0345 464 0079 or drop us an email.
Related advice
How we handle external mastic in Cold Harbour
On houses, flats and commercial buildings across Cold Harbour, we reseal joints in brickwork, render, cladding and façade panels. The preparation is the same whatever the wall: clean, sound faces and a controlled depth. If you have joints pointed up with cement by mistake and gaps where render, brick and frames meet, we can help, on façade panels, joints between brick and frames and copings & trims alike.
Somewhere as small as Cold Harbour, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Gutter joints and wall joints there need a sealant that can flex and stay put.
The work is covered for a year after we finish. If anything isn’t right with it, call 0345 464 0079 or send us an email.
- Where
- Cold Harbour (SL6)
- Region
- Windsor and Maidenhead
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Common questions in Cold Harbour
Is Cold Harbour in your area for external mastic?
Yes. We work across London and the South East, and Cold Harbour is part of that. You can ring 0345 464 0079 or drop us an email and let us know what needs doing.
Is Cold Harbour within the area you cover?
Yes, Cold Harbour is covered. We work across London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
Where are you based?
Our base is in Crawley, West Sussex, and we work across South East England, London and Scotland.
Can a movement joint be filled with mortar?
No. Mortar locks the joint solid, so the wall cracks somewhere else instead. It needs a flexible sealant over backing rod.
Can you quote for more than one area?
Of course. Doing several areas at once is normally more efficient.
Can you match the colour of my brickwork?
The sealant colour is picked to suit the wall, so the joint sits quietly in the wall. There’s a wide choice of exterior colours.
How long before the joint can be used?
That depends on the sealant used, so follow the cure time we give you.
Will you leave a mess?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
What we are called out for in Cold Harbour
Buildings move more than people expect. Brickwork grows a little over the years, blockwork and concrete shrink, and all of it moves with heat and moisture. The sealant in the movement joints takes that strain.
Most people get in touch when they notice something like this:
- Movement joints with cracked, split or missing sealant
- Gaps where render, brick and frames meet
- Water getting into walls through failed joints
- Hard, crazed mastic that has stopped moving
Homes close to Saint Peter include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Comparing quotes
- Which sealant they’ll use, and why
- Who turns up on the day
- When the joint can take water or movement
- Which colour the sealant will be
How we quote for external mastic
Your quote is based on your job. We take into account:
- The old material and how stubborn it is
- Access and height
- The number of rooms or windows
- Whether there’s mould to deal with
Leaving a failed joint normally makes the job bigger, not smaller, because water and mould keep working on it. If you are not sure whether it needs doing, call 0345 464 0079 or send us an email and we will give you an honest view and a quote.
What to tell us for a quote
When you contact us, these details help:
- How we’d reach the joints
- What the problem is, such as mould, gaps, leaks or cracking
- The type of property
- Any previous sealing or DIY work
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will talk you through the work and send you a clear quote.
Can I do it myself?
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
A DIY attempt doesn’t rule out a professional job. We cut it out and start again.
Also near Cold Harbour
What else we do in Cold Harbour
Outside joints around Cold Harbour
With historic houses such as Harleyford Manor (about 3.3 miles north) nearby, there’s older building stock in the area around Cold Harbour as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For site and facilities teams at buildings such as Knowl Hill Church of England Primary Academy, its movement joints, gutters and trims need looking after like any other building’s. If you let a flat or house near Wargrave station, split movement joints are easy to miss on a rental until damp shows inside.
Cold Harbour is about 3 miles west of Maidenhead, in Windsor and Maidenhead. For external mastic in and around Cold Harbour, it’s easy to get a quote: please phone 0345 464 0079 or send us an email. We are based in Crawley and cover Windsor and Maidenhead. Cold Harbour is one of 57 towns and villages in Windsor and Maidenhead we cover. There’s also a page for Reading, roughly 9 miles from Cold Harbour.
Our applicators cover all of SL6 for external mastic and the streets around it. We also cover the places around Cold Harbour: Knowl Hill (1 mile north-west), Warren Row (1 mile north-west), Bowsey Hill (2 miles west), Cockpole Green (3 miles north-west) and Wargrave (3 miles west). Within a short drive, we also cover Maidenhead (3 miles east), Windsor (8 miles east), Boyn Hill (3 miles east), North Ascot (8 miles south-east), Cookham (5 miles north-east) and Furze Platt (3 miles north-east).
Local landmarks in Cold Harbour
We work in homes and buildings around Cox Green School and The Royal Oak pub, among other places. The closest station to Cold Harbour is Wargrave station, roughly 3.3 miles west. Well-known places in the area include St Mark's Hospital (2.8 miles north-east). The countryside around Cold Harbour includes Hurley Chalk Pit and Taplow Lake.
Why deal with it now?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Older cottages and farmhouses around Cold Harbour can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Doing several joints on one visit generally makes better use of the time than several visits. You will get one clear quote for the whole job.
Why choose Mr Mastic in Cold Harbour
- You choose the colour before work begins
- Domestic, commercial and hotel work
- Approved under the ARBOMaster scheme
- Fully insured
See what affects the cost and our reviews.
For landlords and businesses
We regularly work with letting and managing agents. Tell us the address, the job and how access works.
Mouldy or split sealant often shows up at the end of a tenancy. We can quote for more than one property at once.
Aftercare tips
A little care helps the new joints last. Our advice:
- Show decorators and builders where the movement joints are
- Have failed joints looked at early
- Leave the joints unpainted unless we’ve said otherwise
- Keep water from gutters off the wall
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.
Once a joint can’t move, the wall finds another way, often as cracks near the joint. Catch it early and you reduce the risk.