Greater London · England
Sand mastic for sash & case windows in Southfields, Greater London
We cover Southfields for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Wind and rain getting in round a sash window
- Gaps where the frame meets the masonry
- Modern sealant on a period surround
Sand mastic in Southfields
We work across Southfields renewing sand mastic on sash windows and doors. Each joint is raked out, prepared and pointed by hand for a neat, traditional finish. We work on tenement windows, period & listed homes and timber door frames, and common reasons people get in touch are patchy fillers round a sash window and weathered mastic on the most exposed windows.
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 Southfields.
Every job is covered by a 12-month guarantee, wherever you are in Greater London.
- Place
- Southfields (SW18, SW19, SW17)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
What we do, step by step
We bring everything the job needs with us. Once we’ve agreed what’s being done, we protect the area and start. Most jobs take a few hours per window, depending on the condition of the joints. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Southfields. It helps if you can point us to a visitor permit or a bay close to the door.
- First, we look at the surrounds with you and agree what needs doing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic is not too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Getting ready for the visit
- Keep children and pets away from the work area
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about parking restrictions
Getting a quote
To get a quote, phone 0345 464 0079 or email us and tell us where the job is and what the problem looks like. We’ll give you a clear quote before any work starts.
Advice
Surface by surface
Brick reveals
Loose mastic comes out and deep gaps are packed before pointing.
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. Sand mastic is shaped by hand to suit.
Towns and villages near Southfields
Also in Southfields
Southfields questions
Is parking a problem for a job in Southfields?
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.
Can you help a landlord with a rental near Earlsfield station?
Yes. We work for landlords and letting agents as well as householders. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
What should I tell you?
A short description and the location, with photos by email if possible. If we need more, we’ll ask.
Does someone need to be in?
It depends on the job. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Do you work for hotels and businesses?
Yes. We work in offices, washrooms, hotels and other commercial premises, as well as homes. We can talk about working times when we quote.
Is consent needed for window work on a listed home?
Yes, it’s worth checking. Your local planning authority can say if consent is needed for work on a listed home or in a conservation area.
Is sand mastic better than silicone for my windows?
It depends on the window. Period windows in stone or brick generally suit sand mastic, while modern frames normally get a flexible sealant.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned.
Honest limits
It helps to know what we can’t do too:
- Putty and glazing repairs
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sashes that need overhauling
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think.
What we seal
- Brick reveals
- Stone surrounds
- Timber door frames
- Sash and case windows
- Period & listed homes
- Tenement windows
Keeping the joints in good condition
So the new joints stay in good condition:
- Inspect the joints round the windows every year or so
- Leave the new mastic unpainted
- Have rotten timber repaired before new mastic goes in
- Avoid heavy scraping on the mastic joint
Check the mastic when you check the paintwork. Small cracks are easier to deal with early.
Good mastic helps keep the frame dry. Failed mastic lets water reach the timber, which can lead to rot.
How we quote for sand mastic
You will get a clear quote before we start. It’s based on:
- Whether old sealant or filler has to be cut out
- Mould in or behind the old joints
- Access and height
- The product the joint needs
The cost depends on how much there is to do, how much old material has to come out and access to the work. We give a clear quote before we start.
What to tell us for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- Roughly how big the job is
- Where the property is
- Any previous sealing or DIY work
- What’s wrong with the joints now
If you’re in Southfields and need sand mastic, phone 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and you will get a clear quote before work begins.
Sand mastic in Southfields: local notes
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Rented homes near Earlsfield station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about. If you look after a building such as Floreat Wandsworth Primary School, its window and door frames need their mastic kept sound, just like a home’s. As a London address, Southfields can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Southfields is about 2 miles north-east of Wimbledon, in Greater London. Homes, rented property, offices and hotels in Southfields can book us for sand mastic, old or new, large or small. The work is guaranteed for a year. Our area takes in 764 places across Greater London. There’s also a page for London, roughly 6 miles from Southfields.
Work in SW18, SW19 and SW17 is quoted and booked the same way as anywhere else. Local streets include Burr Road, Acuba Road and Mount Road, and we cover them all. We also cover Earlsfield (1 mile south-east), Wandsworth (1 mile north), Summerstown (1 mile south), Battersea (2 miles north-east) and Clapham Junction (2 miles north-east). Within a short drive, we also cover London (6 miles north-east), City of Westminster (5 miles north), Marylebone (5 miles north), Kensington (4 miles north), St Pancras (6 miles north-east) and Shoreditch (7 miles north-east).
Around Southfields
Around Southfields, our work takes us to homes and buildings near Old Sergeant pub, Southfields Academy and Wandsworth School. Southfields has its own railway station: Earlsfield station. Nearby you will also find Royal Hospital for Neuro-disability (1 mile west) and Wimbledon Lawn Tennis Museum (1.2 miles south-west). Open spaces near Southfields include Henman Hill and Wandle Meadow Nature Park.
Landlord and commercial work in Southfields
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Why act early in Southfields
Not every filler suits an old window surround. Sand mastic is the like-for-like choice, which can matter on listed and conservation-area homes. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Southfields, the repair is bigger than the sealant job would have been.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you’re unsure, ring 0345 464 0079 or send us an email for an honest opinion and a quote.
Why Southfields customers choose us
- 4.9 on Google from 180+ five-star reviews
- 12-month guarantee on every job
- Tidy, careful work
- Anti-fungal sanitary silicone in wet areas