Windsor and Maidenhead · England
Sand Mastic in Old Windsor
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for homes and businesses in Old Windsor and across Windsor and Maidenhead. Fully insured, ARBOMaster approved and guaranteed for a year.
- Wind and rain getting in round a sash window
- Mastic dropping out of the joint
- Failed mastic on an exposed elevation
Common problems we fix in Old Windsor
Timber swells and shrinks with the weather. That movement opens up the mastic joint little by little.
The problems people generally mention when they call are:
- Weathered mastic on the most exposed windows
- Old cement repairs round a window that have failed
- Draughts and rain around sash boxes
- Silicone on a period window that looks wrong
Schools such as King's Court First School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
What your quote should include
- When the joint can take water or movement
- What product goes in the joint
- Who turns up on the day
- How the joint is cleaned and prepared
How we handle sand mastic in Old Windsor
Sand mastic suits most period window surrounds. Newer frames generally get a flexible sealant instead, and we will talk through which suits your home. We work on timber door frames, sash and case windows and brick reveals, and common reasons people get in touch are silicone on a period window that looks wrong and crumbling sand mastic round a window.
Many houses in smaller places like Old Windsor have conservatories, garden rooms or patio doors. Those joints need the same attention as the main windows.
The work is covered for a year after we finish. If there’s a problem with it, please phone 0345 464 0079 or email us.
- Place
- Old Windsor (SL4)
- Wider area
- Windsor and Maidenhead
- Cover
- One year on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
DIY versus a professional finish
Not every job suits DIY: 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’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so just mention it when you contact us.
Landlords, agents and businesses in Old Windsor
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together, and we are fully insured.
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Your questions about sand mastic in Old Windsor
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. Just mention lanes, gates or anything else about the route when you book.
Can you do sand mastic in Old Windsor?
Yes. We work across London and the South East, and Old Windsor is part of that. Just call 0345 464 0079 or email us with a few details of the job.
Can I choose the sealant colour?
We’ll suggest a colour to suit the surroundings. The product needed can limit the range.
Is sand mastic better than silicone for my windows?
Sand mastic usually suits period timber windows best. Modern frames normally suit a flexible sealant, and we’ll explain why.
Is consent needed for window work on a listed home?
Check with your local planning authority. They decide whether consent is needed for work to your windows.
Can you quote for more than one area?
Yes, and it often makes sense. Combining jobs makes good use of the visit.
Do I need to be at home?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you don’t need to watch us work.
Do you do commercial work?
Yes, regularly. We can plan bigger jobs in stages.
What sealant work cannot fix
We will always be straight with you, so here’s what sealant cannot fix:
- Cracked or broken glass
- Decisions on consent for listed homes
- Sashes that need overhauling
Not sure which it is? You can call 0345 464 0079 or send us an email and we’ll tell you honestly.
Where we work in Old Windsor
- Sash and case windows
- Period & listed homes
- Brick reveals
- Timber door frames
- Stone surrounds
- Tenement windows
The process
At the end, we look at the finished work together. The visit itself usually takes a few hours for a single window, longer for several, depending on how much there is to do. For a job in Old Windsor, we agree the time, the access and parking before the day. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- We look at the surrounds with you and agree the joints to renew.
- We remove the old, loose mastic.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- For indoor joints, keep the area dry beforehand if you can
- Keep children and pets away from the work area
- Let us know about earlier repairs to the joints
Ask for a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will talk you through what we’d do. When it suits you, phone 0345 464 0079 or drop us an email.
Advice
How we quote for sand mastic
For a quick quote, just ask. What matters most is:
- The number of rooms or windows
- Mould in or behind the old joints
- The type of sealant required
- How much old sealant there is and how hard it is to remove
Combining jobs into one visit normally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- How many joints, rooms or windows are involved
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it’s a home or a business
Asking for a quote is easy: let us know the job and the location. Photos by email help us understand the job, and we’ll come back to you with a quote.
Also near Old Windsor
Also in Old Windsor
Why deal with it now?
Not every filler suits an old window surround. Sand mastic is the like-for-like choice, which can matter on listed and conservation-area homes. Homes in smaller places like Old Windsor can face more weather, and failed outside joints let damp into walls. Indoors, a failed seal lets water into floors and panels as it would anywhere.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether the work is at height. We take all of that into account in your quote.
Why choose Mr Mastic in Old Windsor
- 20+ years of sealant experience
- Neat joints and a tidy finish
- 180+ five-star Google reviews
- Anti-fungal silicone where joints get wet
See our cost guide and what customers say.
Sand mastic in Old Windsor: local notes
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. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. 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.
In the older streets around St Luke, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Rented homes near Sunnymeads station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Old Windsor is about 2 miles north-west of Egham, in Windsor and Maidenhead. If you need sand mastic in Old Windsor, please phone 0345 464 0079 or email us for a quick quote. We cover Windsor and Maidenhead from our Crawley base, Old Windsor included. Old Windsor is one of 57 towns and villages in Windsor and Maidenhead where we work. Reading is on our list too, around 17 miles away.
Jobs for sand mastic in SL4 works the same way as everywhere else we cover. Local streets include Church Road, Parker Gardens and Gregory Drive, all of which we cover. Being close to the B3021, Old Windsor is simple for us to get to for sand mastic. Other places close to Old Windsor include Wraysbury (1 mile east), Sunnymeads (1 mile north-east), Bishopsgate (1 mile south), Datchet (2 miles north) and Englefield Green (2 miles south). Within a short drive, we also cover 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).
Local landmarks in Old Windsor
In Old Windsor, that means homes and buildings near St John's Beaumont School, Windsor Great Park and The Fox And Castle Public House. The nearest railway station is Sunnymeads station, roughly 1.3 miles north-east of the centre. 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.