Greater London · England
Sand Mastic in South Kensington
Professional sand mastic in and around South Kensington, with old sealant always removed completely and a one-year guarantee.
- Cracked mastic round a front door frame
- Weathered mastic on the most exposed windows
- Patchy fillers round a sash window
About our sand mastic in South Kensington
Burnt sand mastic is a traditional material that sits naturally against stone and brick. It suits period and listed homes, where modern sealant can look out of place. We work on sash and case windows, timber door frames and brick reveals, and the jobs we see most are mastic dropping out of the joint and open joints round the window box.
From mansion-block windows to modern glazing in new flats, London has every kind of frame. The mastic around them dries out and cracks with age, which is when draughts and damp patches appear in homes in South Kensington.
All our work comes with our one-year guarantee.
- Place
- South Kensington (SW3, SW7, SW10)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Keeping the joints in good condition
A little care helps the new joints last. We recommend:
- Ask a joiner to look at soft timber first
- Sort the mastic before the decorators arrive
- Avoid patching sand mastic with silicone
- Clear gutters so water doesn’t pour onto the windows
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look before trying a quick fix.
Gaps round a sash box let in draughts and rain. The longer it’s left, the more the joint opens.
Frames and glazing around South Kensington
With historic houses such as Carlyle's House (about 0.6 miles south-east) nearby, there’s older building stock in the area around South Kensington as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
South Kensington is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. Managing a site like Our Lady of Victories RC Primary School? Then the mastic around its windows and doors needs looking after like any other building’s. For landlords with property near West Brompton station, cracked sand mastic around sash windows lets in the draughts tenants complain about.
South Kensington is about 1 mile south-east of Kensington, in Greater London. For sand mastic in and around South Kensington, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Greater London, South Kensington included. South Kensington is one of 764 towns and villages in Greater London we cover for sand mastic.
All of SW3, SW7 and SW10 is within our area for sand mastic, from the main roads to the quietest streets. We cover properties on King's Road, Fulham Road and Museum Lane and the roads around them. South Kensington is on the A3217, which makes it straightforward to reach. Neighbouring places we cover for sand mastic include Little Chelsea (1 mile south), Chelsea (1 mile east), Brompton (1 mile north-east), World's End (1 mile south) and Earl's Court (1 mile west). Larger places within reach include London (4 miles east), St Pancras (4 miles north-east), Shoreditch (5 miles north-east), Walthamstow (9 miles north-east), Hoxton (5 miles north-east) and Whitechapel (5 miles east).
What’s near South Kensington
Typical jobs here are in homes near London School of Dramatic Art, Burton’s Court and Anglesea Arms, among other places. Also close by are Natural History Museum Library and Archives (within half a mile north) and Collingham College (0.5 miles west). The nearest railway station is West Brompton station, about 0.8 miles west of the centre. Nearby you will also find Victoria and Albert Museum Spiral (less than half a mile north) and Baynard's Castle (3.6 miles north-east). For a walk, there’s Serpentine and Campden Hill.
Questions from South Kensington
Is parking a problem for a job in South Kensington?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Is South Kensington in your area for sand mastic?
Yes, South Kensington is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
Can tenants book the work?
Yes. Check with your landlord; we can send the quote to them too.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us.
Can I paint the new mastic?
The usual advice is to leave sand mastic unpainted. Ask us before you decorate around it and we will talk you through it.
What sealant do you use?
The product depends on the job: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. We use products from Arbo and Everbuild.
Is there any odour?
There can be a smell while the sealant cures, which fades as it sets. Ventilation helps.
Do you have insurance?
Yes. We’re fully insured for domestic and commercial work.
What we can’t put right
Before you book, it’s worth knowing the limits too:
- Planning or listed building consent (your local planning authority decides)
- Timber that has rotted
- Crumbling stone or brickwork round the window
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think.
What we seal
- Stone surrounds
- Brick reveals
- Sash and case windows
- Period & listed homes
- Tenement windows
- Timber door frames
DIY versus a professional finish
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
What happens on the day
Our applicators work methodically: protect, prepare, seal, tidy. For most jobs that takes anything from a few hours to a full day, depending on how many windows and we leave things clean and tidy. 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 check each window surround and the condition of the joint.
- The joint is raked out and cleaned.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Mention any parking rules near the property
- Keep pets and children clear of the area while we work
- Where the joints are inside, avoid wetting them before we arrive
Get a quote
Getting a quote is simple: tell us what needs doing and where. Photos by email help us understand the job, and we’ll come back to you with a quote.
Advice
Different surfaces, different methods
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair so it’s worth checking responsibilities.
Brick reveals
An open joint at a brick reveal lets weather in. New mastic seals the gap.
Nearby places to South Kensington
Also in South Kensington
Why deal with it now?
Filling over old, loose mastic doesn’t last. Raking out and preparing the joint gives it a sound base so the new mastic stays put. Damp from a failed joint spreads quietly in older London brickwork and timber, and by the time it shows on a wall or ceiling in South Kensington, the repair is bigger than the sealant job would have been.
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. We take all of that into account in your quote.
Why choose Mr Mastic in South Kensington
- Quality sealants from Arbo and Everbuild
- 4.9 on Google from 180+ five-star reviews
- Experience in homes, commercial sites and hotels
- A 12-month guarantee on all work
Read what affects the cost and what customers say.
Landlord and commercial work in South Kensington
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
Housing providers, facilities teams and property managers book us too in South Kensington and across Greater London. We can quote a run of properties together, and we’re fully insured for the work.