Greater London · England
Hendon Sand Mastic
We cover Hendon for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Old sand mastic that has cracked, crumbled or fallen out
- Old cement repairs round a window that have failed
- Gaps between timber frames and stone or brick
What we’re called out for in Hendon
Timber frames move with the seasons. The movement cracks the mastic little by little.
Keep an eye out for these signs:
- Failed mastic on an exposed elevation
- Wind and rain getting in round a sash window
- A silicone bead on a sash window that spoils the look
- Mastic dropping out of the joint
Rented homes near Hendon station change hands often, and any sash windows need sound mastic to keep draughts and rain out.
What your quote should include
- How the colour is chosen
- What preparation is included
- What happens if the job turns out different
- Whether they’re fully insured
Sand mastic for homes and businesses in Hendon
Across Hendon, we renew sand mastic around sash and case windows. Every joint is cleaned out and filled by hand, finished to suit the masonry. Common call-outs are for mastic round period door frames that has failed and crumbling sand mastic round a window, on sash and case windows, period & listed homes and brick reveals.
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 Hendon as anywhere.
Our work is backed for twelve months.
- Where
- Hendon (NW4, NW9, NW2, NW11)
- Region
- Greater London
- Cover
- 12 months on all our work
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What else we do in Hendon
When it is not the sealant
A few problems are outside what sealant work can do:
- Putty and glazing repairs
- Rotten sashes, sills or window boxes (a joiner’s job)
- Decisions on consent for listed homes
If you are not sure, just phone 0345 464 0079 or email us and we will give you a straight answer.
What we seal
- Tenement windows
- Brick reveals
- Stone surrounds
- Sash and case windows
- Period & listed homes
- Timber door frames
Hendon questions
Is parking a problem for a job in Hendon?
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.
Do you cover Hendon for sand mastic?
Yes. We work across London and the South East, and Hendon is part of that. You can phone 0345 464 0079 or drop us an email and tell us what needs doing, and we will give you a clear quote.
Can I do it myself?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
How long does the job take?
Typically it takes anything from a few hours to a full day, depending on how many windows. Larger jobs naturally take longer.
Can sand mastic be painted?
It’s traditionally left unpainted, which is what traditional guidance recommends. Talk to us before any painting near it.
Do you take out the old sealant first?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
What’s sand mastic made of?
Sand plus a binder based on linseed oil. It’s built up in the joint by hand and finished to sit neatly against the masonry.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status.
What sand mastic looks like in Hendon
Historic houses like Heath Hall (about 2.3 miles east) are a reminder that the area around Hendon has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
For site and facilities teams at buildings such as Hendon School, larger buildings have plenty of frames, and the mastic around each one ages. Hendon is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Hendon is about 3 miles north-west of Hampstead, in Greater London. Every kind of property in Hendon is covered for sand mastic. Every job comes with our one-year guarantee. We cover 764 towns and villages across Greater London, large and small. For nearby work, see our London page.
Every address in NW4, NW9, NW2 and NW11 is within our area for sand mastic, from the main roads to the quietest streets. If you need sand mastic at a property on Church Road, Station Road and Sydney Grove or a nearby road, we can help. With the A5 and A41 close by, Hendon is easy for our applicators to reach for sand mastic. We also cover The Burroughs (1 mile north-west), Brent Cross (1 mile south), Staples Corner (1 mile south), West Hendon (1 mile west) and The Hyde (1 mile west). Further out, we also cover London (8 miles south-east), City of Westminster (6 miles south-east), Marylebone (6 miles south-east), Kensington (6 miles south), St Pancras (6 miles south-east) and Shoreditch (7 miles south-east).
Around Hendon
Around Hendon, our work takes us to homes and buildings near Hasmonean Primary School, The White Bear pub and Kisharon College, among other places. The nearest railway station is Hendon station, about 0.7 miles south-west. Well-known places in the area include Brent Cross Shopping Centre (0.5 miles south) and St Andrew's Hospital (1.6 miles south). Not far away are Darland's Lake and Parliament Hill.
Why it’s worth doing now in Hendon
If you’re redecorating, renew the mastic first. Painting over failed mastic doesn’t seal it, and the new mastic is traditionally left unpainted. 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 Hendon, the repair is bigger than the sealant job would have been.
The cost reflects the work involved, not a rough estimate. That is why we ask a few questions first.
Why choose Mr Mastic in Hendon
- 4.9 on Google from 180+ five-star reviews
- Anti-fungal sanitary silicone in wet areas
- We leave the area clean and tidy
- Approved under the ARBOMaster scheme
DIY versus a professional finish
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
How the visit works
A visit follows a simple pattern: we check the joints, protect the area around them, do the work and tidy away. It normally takes a few hours per window, depending on the condition of the joints. In a London area like Hendon, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- Each surround is checked first.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Let us know about parking restrictions
- Clear the area around the work
- Mention any tricky access
Getting a quote
Every job is quoted individually. Simply ring 0345 464 0079 or email us and describe the job.
Advice
For landlords and businesses
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
Surface by surface
Tenement and terrace windows
Where a building is shared, window work may involve neighbours, so check who is responsible first.
Stone surrounds
The stone is treated with care while raking out the old mastic.