Greater London · England
Brent Cross Sand Mastic
Sand mastic in Brent Cross from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Failed mastic on an exposed elevation
- Mastic that needs renewing before redecorating
- Draughts and rain around sash boxes
Sand mastic in Brent Cross
Sand mastic doesn’t last for ever, leaving gaps round the window. We rake it out and renew it and tidies the surround. If you are dealing with mastic round period door frames that has failed and mastic worn away on windows facing the weather, we can put it right, whatever the surface.
London has a lot of flats and conversions, where windows are often on upper floors. Who looks after the outside of the frames can depend on the lease, so check that first.
Whatever the size of the job, it’s backed by our one-year guarantee.
- Place
- Brent Cross (NW4, NW11, NW2)
- Wider area
- Greater London
- Cover
- One year on every job
- Quote
- A clear price before work begins
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Why it’s worth doing now in Brent Cross
Before painting the windows, it pays to renew the mastic. Painting over failed mastic does not seal it and traditional guidance is to leave the new mastic unpainted. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble for homes in Brent Cross.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
Why choose Mr Mastic in Brent Cross
- Neat joints and a tidy finish
- Every job guaranteed for a year
- We are fully insured
- 180+ five-star Google reviews
Read our cost guide and our reviews.
Honest limits
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Decisions on consent for listed homes
- Damaged stone surrounds
- Putty and glazing repairs
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
What we seal
- Period & listed homes
- Timber door frames
- Sash and case windows
- Tenement windows
- Brick reveals
- Stone surrounds
Different surfaces, different methods
Tenement and terrace windows
Where a building is shared, window work may involve neighbours, so check who is responsible first.
Period and listed homes
Materials matter on listed and conservation-area homes. Sand mastic is often the preferred finish.
Brent Cross homes and the weather
In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking. Historic houses like Heath House (about 1.9 miles south-east) are a reminder that the area around Brent Cross 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.
For landlords with property near Brent Cross West station, older sash windows in a rental need their mastic kept sound to keep the weather out. If you live in an older home near Christ Church Hendon, the joint between an old wall and a newer frame is normally the first place rain gets in.
Brent Cross is about 2 miles north-west of West Hampstead, in Greater London. Every kind of property in Brent Cross can book us for sand mastic, old or new, large or small. Every job comes with our 12-month guarantee. Brent Cross is one of 764 towns and villages in Greater London where we work. Our London page covers work nearby.
Our applicators cover all of NW4, NW11 and NW2 for sand mastic. Streets in the area include Park Road, Graham Road and Elliot Road, all of which we cover. Brent Cross sits on or near the A41. If you are just outside Brent Cross, we cover Hendon (1 mile north), Staples Corner (1 mile south-west), The Burroughs (1 mile north-west), Dollis Hill (1 mile south-west) and The Hyde (1 mile west). Further out, we also cover London (8 miles south-east), City of Westminster (5 miles south-east), Marylebone (5 miles south-east), Kensington (5 miles south), St Pancras (6 miles south-east) and Shoreditch (7 miles south-east).
Near you in Brent Cross
Locally, jobs take us to homes and businesses close to Kisharon College, Hasmonean Primary School and The White Bear pub. The nearest railway station is Brent Cross West station, about 0.7 miles south-west. Other landmarks nearby include St Andrew's Hospital (1.2 miles south-west) and Brent Cross Shopping Centre (under half a mile west). For a walk, there’s Darland's Lake and Parliament Hill.
What we’re called out for in Brent Cross
Timber frames move with the seasons. The movement cracks the mastic over time.
It’s worth asking for a quote if you see:
- Gaps round a timber door in stone or brick
- Modern sealant on a period surround
- Draughts and rain around sash boxes
- Patchy fillers round a sash window
As a London address, Brent Cross can be tricky for parking: let us know about parking bays, permits or a driveway.
What your quote should include
- Which colour the sealant will be
- Who does the work, and how experienced they are
- Whether they seal over old material or remove it
- What product goes in the joint
How it works
There’s no need to move everything out, just the space around the work. We protect the rest, and the job takes anything from a few hours to a full day, depending on how many windows 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
- Clear the area around the work
- Keep children and pets away from the work area
- Let us know about stairs, lifts or work at height
How to get a quote
Asking for a quote is easy: let us know what needs doing and where. Photos by email help us understand the job.
Advice
DIY versus a professional finish
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly.
Common questions in Brent Cross
Do you cover Brent Cross for sand mastic?
Yes. We work across London and the South East, and Brent Cross is part of that. You can phone 0345 464 0079 or email us and tell us what needs doing.
Can parking be tricky for a visit in Brent Cross?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
I rent my home. Can I book you?
Of course. Ask your landlord first, and we can send them the quote if that helps.
How long does sand mastic take to harden?
The surface skins quite quickly and it hardens fully over a longer time. The weather and joint depth both affect it.
Is there any odour?
It depends on the product. Some products have a noticeable smell, others very little.
What does sand mastic cost?
Size, access and the old material all affect the cost. Call for a quick quote.
Do you offer different sealant colours?
Yes. White, clear and grey are common, and other colours are available, and we’ll agree it with you first.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We will tell you what we are using and why.
Nearby places to Brent Cross
Other services in Brent Cross
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Look over the window mastic once a year
- Sort the mastic before the decorators arrive
- Ask the planning authority about consent for listed or conservation-area homes
- Do not paint over the new mastic
Don’t touch or press the mastic while it hardens. It skins over quickly but needs longer to fully harden.
An open joint round the box lets weather through. Left, the gap tends to get bigger as more mastic falls out.