Greater London · England
Morden Sand Mastic
Our applicators work in Morden on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Patchy fillers round a sash window
- Crumbling sand mastic round a window
- Wind and rain getting in round a sash window
Sand mastic in Morden
If your home is listed or in a conservation area, check with your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. If you have draughty sash windows at the surround and gaps round a timber door in stone or brick, we can put it right.
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.
All our work is covered by a 12-month guarantee, wherever you are in Greater London.
- Place
- Morden (SM4, SM3, SW20)
- Region
- Greater London
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Common problems we fix in Morden
Age is the main cause. Even well-laid mastic needs renewing in time and how long it lasts depends on the weather it faces.
If you can see any of these, it’s time to have the joints looked at:
- Gaps round a timber door in stone or brick
- Silicone on a period window that looks wrong
- Mastic dropping out of the joint
- Window mastic to renew ahead of painting
For site and facilities teams at buildings such as Morden Primary School, its window and door frames need their mastic kept sound, just like a home’s.
Questions to ask before booking
- What guarantee comes with the work
- How the surfaces are prepared before sealing
- How hidden problems are handled
- What the cure time is
What happens if it’s left?
Draughts round a sash window aren’t always the sashes. Gaps between the frame and the wall can be just as bad, and renewing the mastic closes them. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and once it shows in Morden, the repair is bigger than a sealant job.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Why book with us
- Over 20 years’ experience
- Fully insured
- Anti-fungal sanitary silicone in wet areas
- 4.9 on Google from 180+ five-star reviews
Read our cost guide or our reviews.
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, and the work is guaranteed for a year.
Other services in Morden
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours per window, depending on the condition of the joints and we leave things clean and tidy. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Morden. A visitor permit or a nearby bay makes the visit run more smoothly.
- We start by checking each surround and agreeing the joints to renew.
- Old, loose mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- The mastic is mixed, pressed into the joint by hand and shaped.
- We dress the surface so it sits neatly against the masonry.
How to prepare
- Let us know about parking restrictions
- Mention any tricky access
- For business premises, tell us about site rules or sign-in
Ask for a quote
For a quick quote, get us on the phone, or send an email if you’d rather. Describe what needs sealing and we will talk you through the work and give you a clear price.
Advice
For landlords and businesses
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. We have worked in hotels as well as homes and businesses.
If you manage several properties in or around Morden, several properties can be quoted together. Send us the addresses and the work at each, and photos by email help.
Questions from Morden
Can you help a landlord with a rental near St Helier station?
Yes, landlords and agents are among the people we work for. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Can you do sand mastic in Morden?
Yes. We work across London and the South East, and Morden is part of that. Just ring 0345 464 0079 or email us with a few details of the job.
Do you have insurance?
Yes, we are fully insured for domestic and commercial work.
Is it worth trying it myself?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
What’s sand mastic made of?
Sand mastic is a traditional material for pointing round windows and doors. It combines sand with a linseed-oil-based binder.
Is it possible to take out silicone and use sand mastic instead?
Yes, it’s a common request. The old silicone has to come out completely so the mastic can sit properly.
Which is right for my windows, sand mastic or modern sealant?
That depends on your windows. On many period windows, sand mastic looks right and suits the building and newer frames normally get a flexible sealant.
Do you hold any approvals?
Yes. We are an ARBOMaster approved applicator.
Looking after it afterwards
So the new joints stay in good condition:
- Don’t run silicone over sand mastic
- Go gently near the mastic when preparing windows
- Check the mastic when you check the paintwork
- Have rotten timber repaired before new mastic goes in
Do not run silicone over the new mastic. If anything cracks, get it looked at before trying a quick fix.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.
Morden homes and the weather
With historic houses such as Southside House (about 1.9 miles north-west) nearby, there’s older building stock in the area around Morden as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
As a London address, Morden can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Letting a property close to St Helier station? Then any sash windows need sound mastic to keep draughts and rain out.
Morden is about 2 miles south of Wimbledon, in Greater London. Anywhere in SM4, we cover sand mastic for homes and businesses. Morden is one of 764 towns and villages in Greater London we cover. We also work in London, about 9 miles from Morden.
All of SM4, SM3 and SW20 is within our area for sand mastic, from the main roads to the quietest streets. You’ll find streets such as London Road, Epsom Road and Holne Chase, and we cover them all. Morden is on the B279, which makes it straightforward to reach. We also cover Lower Morden (1 mile south-west), Sutton Common (1 mile south-east), North Cheam (2 miles south), Worcester Park (2 miles south-west) and Stoneleigh (3 miles south-west). Further out, we also cover London (9 miles north-east), City of Westminster (9 miles north), Marylebone (9 miles north), Kensington (7 miles north), St Pancras (10 miles north-east) and Shoreditch (11 miles north-east).
Around Morden
In Morden, that means homes and buildings near Lord Nelson pub, Glenthorne High School and Cannon Hill Common. Morden has its own railway station: St Helier station. A little further out are St. Anthony's Hospital (1 mile south-west) and Chessington Castle Hill (4.3 miles south-west). The countryside around Morden includes Henman Hill and Morden Park (park).
When it is not the sealant
We will not take on work that will not last, so these are the limits:
- Crumbling stone or brickwork round the window
- Planning or listed building consent (your local planning authority decides)
- Putty and glazing repairs
If you are not sure, just call 0345 464 0079 or send us an email and we will give you a straight answer.
Joints and surfaces we work on
- Timber door frames
- Tenement windows
- Period & listed homes
- Stone surrounds
- Brick reveals
- Sash and case windows