Greater London · England
Sand Mastic in Kensal Green
Sand mastic across Kensal Green and nearby, with old sealant always removed completely and a one-year guarantee.
- Patchy fillers round a sash window
- Cracked mastic round a front door frame
- Weathered mastic on the most exposed windows
How we handle sand mastic in Kensal Green
We renew sand mastic around sash windows and doors set in stone or brick. The old mastic is raked out, and new mastic is applied and shaped by hand. We work on period & listed homes, sash and case windows and brick reveals, and the jobs we see most are modern sealant on a period surround and cement or filler used on old window joints that has cracked.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Whatever is in the opening now, the joint between frame and wall is what keeps the weather out, in Kensal Green as anywhere.
The work is covered for a year after we finish. If there’s a problem with it, please ring 0345 464 0079 or drop us an email.
- Where
- Kensal Green (NW10, W10, NW6)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What affects the cost of sand mastic
Every job gets its own quote. This is what makes a difference:
- Working hours on commercial sites
- The number of rooms or windows
- The number and length of the joints
- How easy the joints are to reach
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, along with when we can work on site. Call for a quick quote and we will explain what it covers.
Asking for a quote
You do not need to know the technical terms. It helps if you can tell us:
- How we’d reach the joints
- If it’s domestic, commercial or a hotel
- A few pictures by email, if you can
- Any previous sealing or DIY work
There’s no standard price list. Instead, your job gets its own clear quote. To arrange one, call 0345 464 0079 or send us an email.
Different surfaces, different methods
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. We renew it the same way as on windows.
Stone surrounds
The stone is treated with care when the old mastic comes out.
The process
When we arrive, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before work begins. Most jobs take a few hours for a single window, longer for several. 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 start by checking each surround and agreeing the joints to renew.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- We dress the surface so it sits neatly against the masonry.
Getting ready for the visit
- 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
- For business premises, tell us about site rules or sign-in
Get a quote
Getting a quote is simple: tell us what needs doing and where and its rough size. Photos by email help us understand the job.
Read more
Common problems we fix in Kensal Green
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:
- Draughts and rain around sash boxes
- Failed mastic on an exposed elevation
- Crumbling sand mastic round a window
- Gaps round a timber door in stone or brick
Schools such as Princess Frederica CofE Primary School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
What to look for in a quote
- The length of the guarantee
- When the joint can take water or movement
- What product goes in the joint
- How hidden problems are handled
Honest limits
In fairness, there are a few things sealant will not fix:
- Putty and glazing repairs
- Timber that has rotted
- Sash cords, weights and draught-proofing of the sashes
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
Where we work in Kensal Green
- Timber door frames
- Stone surrounds
- Period & listed homes
- Sash and case windows
- Brick reveals
- Tenement windows
Leave it or put it right?
A silicone bead can be quicker, but it can look wrong on a period surround. Sand mastic is the traditional material and blends with the stone or brick. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether the work is at height. Your quote takes all of that into account.
Why choose Mr Mastic in Kensal Green
- Experience in homes, commercial sites and hotels
- Any old sealant cut out fully, not covered over
- Anti-fungal sanitary silicone in wet areas
- Every job guaranteed for a year
See what affects the cost and customer reviews.
Your questions about sand mastic in Kensal Green
Can parking be tricky for a visit in Kensal Green?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Is Kensal Green in your area for sand mastic?
Yes. Our work covers London and the South East, and Kensal Green is part of that. Just call 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear price.
Do you hold any approvals?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Are you insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Can landlords and businesses book you?
Yes. Domestic, commercial and hotel work are all part of what we do, and we are fully insured.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that generally means someone at home.
Do I need permission for sand mastic on a listed building?
It’s best to ask your local planning authority first. Sand mastic is often favoured as like for like, but they decide.
When will the new mastic be hard?
It skins over fairly quickly but takes longer to harden fully. We’ll tell you what to expect for your job.
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Ask us before painting near the mastic
- Look over the window mastic once a year
- Sort the mastic before the decorators arrive
- Go gently near the mastic when preparing windows
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at rather than patching it.
Fine cracks show the mastic is starting to fail. Renewing it then is simpler than waiting until it falls out.
Frames and glazing around Kensal Green
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. 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.
Kensal Green is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. If you live in an older home near St Martin, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Kensal Green is about 1 mile south-west of Kilburn, in Greater London. Every kind of property in Kensal Green is covered for sand mastic, old or new, large or small. Every job comes with our one-year guarantee. We cover 764 towns and villages across Greater London, from the larger towns to small villages. Our London page covers work nearby.
Postcode districts we cover here for sand mastic: NW10, W10 and NW6. Streets in the area include Waldo Road, Hazel Road and Hiley Road, and we cover them all. If you are just outside Kensal Green, we cover Kensal Rise (1 mile east), College Park (1 mile west), North Kensington (1 mile south-east), Willesden Green (1 mile north) and Kensal Town (1 mile south-east). We also work in nearby towns such as London (6 miles east), City of Westminster (3 miles east), Marylebone (3 miles east), St Pancras (5 miles east), Shoreditch (6 miles east) and Walthamstow (9 miles north-east).
Around Kensal Green
Locally, jobs take us to homes and businesses close to Little Wormwood Scrubs, Queens Park Community School and The Masons Arms. Kensal Green has its own railway station: Kensal Green station. Well-known places in the area include Westfield London (1.6 miles south) and Princess Louise Hospital (0.7 miles south). Green spaces nearby include Greville Place nature reserve and The Long Water.