Greater London · England
Sand mastic for sash & case windows in Brompton, Greater London
Sand mastic for Brompton and the surrounding area: careful preparation, the right product and tidy work. Call for a quick quote.
- Tired mastic found when preparing windows for paint
- Patchy fillers round a sash window
- Old sand mastic that has cracked, crumbled or fallen out
Questions from Brompton
Can you do sand mastic in Brompton?
Yes, Brompton is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Can you help a landlord with a rental near London Victoria station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Can I paint the new mastic?
It’s traditionally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Should I check with the council before work on a listed or conservation-area home?
Checking first is sensible. Your local planning authority can say if consent is needed for work on a listed home or in a conservation area.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
What sealant do you use?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Brompton, along with the rest of our area.
Do you take out the old sealant first?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
Sand mastic in Brompton, done properly
Sand mastic skins over fairly quickly, but it takes longer to harden fully. Traditionally, sand mastic is left unpainted and we’ll advise if you’re redecorating. If you have mastic worn away on windows facing the weather and silicone on a period window that looks wrong, we can help.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in.
Our work is backed for twelve months.
- Place
- Brompton (SW3, SW7, SW1X)
- Wider area
- Greater London
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
Tenement and terrace windows
Where a building is shared, window work may involve neighbours, so check who is responsible first.
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
What affects the cost of sand mastic
Every job gets its own quote. This is what makes a difference:
- Whether there’s mould to deal with
- How many rooms, windows or areas are involved
- The type of sealant required
- Any working-time requirements on site
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or send us an email.
What to tell us for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Roughly how big the job is
- Any access issues, like height or stairs
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or drop us an email.
What sealant work can’t fix
A few problems are outside what sealant work can do:
- Sashes that rattle, stick or won’t open
- Planning or listed building consent (your local planning authority decides)
- Putty and glazing repairs
If you’re not sure, just call 0345 464 0079 or drop us an email and we’ll give you a straight answer.
Where we work in Brompton
- Brick reveals
- Stone surrounds
- Sash and case windows
- Period & listed homes
- Timber door frames
- Tenement windows
When to call us in Brompton
Over the years, sand mastic weathers. It hardens, cracks and starts to come away on the stone or timber.
Keep an eye out for these signs:
- Cracked mastic round a front door frame
- Gaps where the frame meets the masonry
- Mastic worn away on windows facing the weather
- Modern sealant on a period surround
If you look after a building such as Hellenic College of London, larger buildings have plenty of frames, and the mastic around each one ages.
Before booking anyone
- Whether you can choose the colour
- Whether they seal over old material or remove it
- Who turns up on the day
- How the joint is cleaned and prepared
What sand mastic looks like in Brompton
Historic houses like Carlyle's House (about 0.8 miles south) are a reminder that the area around Brompton has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. 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.
As a London address, Brompton can be tricky for parking: let us know about parking bays, permits or a driveway. If you let a flat or house near London Victoria station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Brompton is about 1 mile south of City of Westminster, in Greater London. From the centre of Brompton to the outskirts, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Across Greater London, we cover 764 places, Brompton among them.
We work across SW3, SW7 and SW1X for sand mastic. Whether your property is on West Road, Hans Road and Eaton Lane or anywhere close by, we can help. With the A315 and A3212 close by, Brompton is easy for our applicators to reach for sand mastic. Other places close to Brompton include Chelsea (1 mile south), Belgravia (1 mile north-east), South Kensington (1 mile south-west), Victoria (1 mile east) and Little Chelsea (1 mile south-west). We also work in nearby towns such as London (3 miles east), St Pancras (3 miles north-east), Shoreditch (4 miles north-east), Walthamstow (9 miles north-east), Hoxton (4 miles north-east) and Whitechapel (4 miles east).
What’s near Brompton
We work in homes and buildings around St Thomas More RC Language College, St Joseph's Catholic Primary School and Natural History Museum Library and Archives. Other local landmarks include Shuckburgh Arms (under half a mile south-west) and Burton’s Court (0.5 miles south). Brompton’s nearest station is London Victoria station, roughly 0.8 miles east of the centre. Other landmarks nearby include Baynard's Castle (3 miles east) and Berkshire & Westminster Dragoons Museum (within half a mile south-east). Not far away are Greville Place nature reserve and Serpentine.
Work for landlords, hotels and businesses
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
Why act early in Brompton
Filling over old, loose mastic does not last. Raking out and preparing the joint gives it a sound base so the new mastic stays put. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
The cost reflects the work involved, not guesswork. That’s why we ask about the job first and agree the price before starting.
Why Brompton customers choose us
- Neat joints and a tidy finish
- Trusted Arbo and Everbuild sealants
- 12-month guarantee on every job
- Full insurance on every job
Read our cost guide or customer reviews.
How the visit works
You do not need to clear the whole room or building, just the space around the work. Everything nearby is protected, and the job takes a few hours per window, depending on the condition of the joints in most cases. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- The surface is finished to suit the stone or brick.
Before we arrive
- Try not to wet indoor joints just before the visit
- Mention any parking rules near the property
- Keep pets and children clear of the area while we work
How to get a quote
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 email photos if that is easy.