Windsor and Maidenhead · England
External Mastic in Old Windsor
Our applicators work in Old Windsor on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and a one-year guarantee.
- Failed sealant between panels on a façade
- Damp patches traced to an open external joint
- Joints pointed up with cement by mistake
Your questions about external mastic in Old Windsor
Do you cover Old Windsor for external mastic?
Yes. Our work covers London and the South East, and Old Windsor is part of that. Just call 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear quote.
Will you come out to Old Windsor?
Yes. Old Windsor is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can a movement joint be filled with mortar?
No, not where the gap is a movement joint. Filling it with mortar defeats its purpose, and the wall may crack nearby. We’ll reseal it with a flexible sealant.
Will the new joint stand out?
The aim is a neat, even joint in a colour that suits the wall. We will talk through colour options before we start.
What do you put in the joint?
Each joint gets the product that suits it. Movement, water and weather all affect the choice.
Do you take out the old sealant first?
Yes, always, and completely. New sealant will not bond properly to old, so the joint is cleaned back first.
Will there be a smell?
Sometimes, a little. Any smell clears as the sealant cures, and ventilation helps.
What should I tell you?
The location, the problem and the rough size of the job. Photos by email help too.
How we handle external mastic in Old Windsor
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we’ll confirm what’s needed to reach them safely. If you have movement joints filled with mortar instead of sealant and leaking joints around cladding and façade panels, we can put it right, on joints between brick and frames, copings & trims and render & cladding joints alike.
In and around Old Windsor, older properties sit alongside newer ones, each with its own outside joints. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
Big or small, it’s backed by our one-year guarantee in Old Windsor and across Windsor and Maidenhead.
- Place
- Old Windsor (SL4)
- Region
- Windsor and Maidenhead
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Nearby places to Old Windsor
What else we do in Old Windsor
What external mastic looks like in Old Windsor
Historic houses like Frogmore House (about 1.3 miles north-west) are a reminder that the area around Old Windsor 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. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as King's Court First School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s. If you let a flat or house near Sunnymeads station, outside joints that have cracked can let damp into a rental, so check them between lets.
Old Windsor is about 2 miles north-west of Egham, in Windsor and Maidenhead. For external mastic in and around Old Windsor, it’s easy to get a quote: please ring 0345 464 0079 or email us. We are based in Crawley and cover Windsor and Maidenhead, Old Windsor included. We cover 57 towns and villages across Windsor and Maidenhead, from the larger towns to small villages. There’s also a page for Reading, roughly 17 miles from Old Windsor.
We cover every part of the SL4 postcode area for external mastic. You will find streets such as Church Road, Parker Gardens and Gregory Drive, and we cover them all. Old Windsor is on the B3021, so it’s easy for us to get to with everything needed for external mastic. We also cover Wraysbury (1 mile east), Sunnymeads (1 mile north-east), Bishopsgate (1 mile south), Datchet (2 miles north) and Englefield Green (2 miles south). We also work in nearby towns such as Maidenhead (8 miles north-west), Windsor (3 miles north-west), Boyn Hill (8 miles north-west), North Ascot (6 miles south-west), Cookham (9 miles north-west) and Furze Platt (9 miles north-west).
What’s near Old Windsor
Locally, jobs take us to homes and businesses close to St John's Beaumont School, Windsor Great Park and The Fox And Castle Public House and the streets around them. The closest station to Old Windsor is Sunnymeads station, roughly 1.3 miles north-east. A little further out are Windsor Castle (2.1 miles north-west) and Berkshire Yeomanry Museum (1.6 miles north-west). The countryside around Old Windsor includes St Ann's Hill and Virginia Water Lake.
Honest limits
To be straight with you, there are a few things sealant won’t fix:
- Cracked brickwork or render that needs a builder or plasterer
- Failed render or damaged cladding panels
- Cutting new joints into brickwork, which is building work rather than sealant work
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think before booking.
Surfaces we seal
- Render & cladding joints
- Brickwork movement joints
- Façade panels
- Copings & trims
- Concrete & block
- Joints between brick and frames
What we’re called out for in Old Windsor
The wrong product in a moving joint is a classic cause. A stiff, general-purpose sealant can’t cope with a joint that moves a lot, so it pulls away from the edges.
If you can see any of these, it’s time to have the joints looked at:
- Rain getting behind render or cladding at a joint
- Panel joints letting water in
- Brick movement joints where the sealant has split
- Plants rooting in failed movement joints
If you live in an older home near St Luke, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Questions to ask before you book
- Whether you can choose the colour
- What the quote includes, VAT included or not
- What insurance they hold
- Is the old sealant removed completely?
What affects the cost of external mastic
Your quote is based on your job. We look at:
- How easy the joints are to reach
- The amount of work
- The number of rooms or windows
- Which sealant suits the joint
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are unsure, call 0345 464 0079 or email us and we will give you an honest view and a quote.
Asking for a quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- Roughly how big the job is
- A few photos by email, if you can
- How we’d reach the joints
- Any previous sealing or DIY work
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job.
Why act early in Old Windsor
Running new sealant over the old bead rarely lasts. The new layer can’t bond properly to old, weathered material, so the old joint is cut out fully first. In a smaller place like Old Windsor, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
We don’t show prices on the website, because the cost depends so much on the job itself. Call for a quick quote.
What you get with us
- Tidy, careful work
- White, clear, grey or coloured to suit, where the product allows
- Over 20 years’ experience
- A sealant colour to suit the surroundings
Read what affects the cost and our reviews.
How the job changes by surface
Copings and trims
Joints in copings, parapets and trims are exposed to the worst of the weather. Each is resealed with a weatherproof, flexible sealant.
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so its sealant has to stay flexible.
The process
You don’t need to clear the whole room or building, only the area right around the joints. Everything nearby is protected, and the work takes a few hours to a few days, depending on the length of joint and the access for a typical job. Parking around Old Windsor is generally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
How to prepare
- For indoor joints, keep the area dry beforehand if you can
- Plan for the work area to be out of bounds to pets and children
- Tell us if parking is tricky
How to get a quote
Need a quote? Please ring 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and send you a clear quote before we start.
Advice
Should I try it myself first?
If you’ve already had a go yourself, that’s fine. We cut it out and start again.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.