Greater London · England
Window & door mastic in Balham, Greater London
Professional window mastic in and around Balham, with old sealant always removed completely and a 12-month guarantee.
- Cracked internal joints between frame and plaster
- Mastic that has split away from the wall
- Gaps where the sill meets the wall
Window mastic in Balham, done properly
The new joint doesn’t have to be white. White, brown, anthracite grey, black and clear sealants are all available, so the line suits the frame instead of standing out. Common call-outs are for white mastic on grey or black frames and black, perished sealant on frames, across aluminium frames, uPVC windows and composite doors.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first, and access in Balham is something to talk through when you book.
The work is covered for a year after we finish. If anything is not right with it, call 0345 464 0079 or email us.
- Where
- Balham (SW12, SW17, SW4)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
What we are called out for in Balham
Every frame moves through the day. Sun on a frame makes it expand, and it contracts again overnight, while the brick or render around it hardly moves. If the sealant cannot stretch, it splits.
The problems people normally mention when they call include:
- Rain getting in at the frame or under the sill
- Gaps between the frame and the inside reveal
- Untidy mastic left by window fitters
- Mastic that is falling out in pieces
Schools such as Ravenstone Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
What to look for in a quote
- When the joint can take water or movement
- What the quote includes, VAT included or not
- How the surfaces are prepared before sealing
- How hidden problems are handled
Why it’s worth doing now in Balham
The work is quick compared with the damage it prevents: the visit takes most of a day for a typical house, less for a few frames. Wait for damp to appear and there may be plaster and decorating to sort out too. In a flat in Balham, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Why us?
- A sealant colour to suit the surroundings
- Arbo and Everbuild products
- Every job guaranteed for a year
- Fully insured
Read what affects the cost or customer reviews.
Nearby places to Balham
What else we do in Balham
Can I do it myself?
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Landlords, agents and businesses in Balham
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will quote.
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
FAQs for Balham
Can you do window mastic in Balham?
Yes, Balham is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or email us and tell us what needs doing.
I let a flat near Balham station. Can you help?
Yes. We work for landlords and letting agents as well as homeowners, and several properties can be quoted together. You can phone 0345 464 0079 or email us with the details for a clear quote.
Are you an approved applicator?
Yes. We are an ARBOMaster approved applicator, the approved applicator scheme for Arbo sealants.
Which products do you use?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
What does window mastic cost?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote and we will talk you through it.
Where do you work from?
Our base is in Crawley, West Sussex, and we cover South East England, London and all of Scotland.
Is it messy?
Very little: the area around the joints is protected first, and we clear up the old sealant and our materials before we leave.
Can you do upstairs windows?
Yes, where they can be reached safely. Tell us about access when you get in touch so we can plan the job.
Aftercare tips
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Keep drainage slots and sill grooves clear
- Keep timber frames painted
- Wash the frames with mild soapy water
- Paint up to the joint, not over it
Clean the frames with mild soapy water, and avoid solvent cleaners on the sealant.
Wet, windy weather is when failed mastic shows itself, but sealant goes on best when frames and walls are dry. Dealing with it when you first notice a crack avoids chasing leaks through the wet months.
How it works
Good joint work is mostly preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. In total, it normally takes a few hours for a few frames, or a day or more for a whole house. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. Mention any building rules, key holders or managing agents when you book.
- Each frame is looked over and we agree which ones need resealing.
- The old mastic is cut out and scraped back to clean surfaces.
- Deep gaps get closed-cell backing rod to set the depth.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
Getting ready for the visit
- Let us know if you’ve seen damp or leaks
- Let us know about stairs, lifts or work at height
- Clear items away from the joints we’re working on
Getting a quote
Need a quote? Please ring 0345 464 0079 or email us and tell us about the job. We’ll explain what we’d do and give you a clear price before we start.
Advice
Window mastic in Balham: local notes
In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Balham is in London, so parking needs planning: let us know about parking bays, permits or a driveway. For an older house near a landmark such as Church of St Mary, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Balham is about 2 miles south-west of Stockwell, in Greater London. Across the SW12 area, we cover window mastic for homes and businesses. Across Greater London, we cover 764 places, and Balham is one of them.
Every address in SW12, SW17 and SW4 is covered for window mastic. Whether your property is on Lynn Road, Weir Road and Byrne Road or a nearby road, our applicators can take on the job. Other places close to Balham include Grange Mills (1 mile north-east), Hyde farm estate (1 mile east), Clapham Park (1 mile north-east), Streatham Park (1 mile south-east) and Tooting Bec (1 mile south-west). Larger places within reach include London (5 miles north-east), City of Westminster (5 miles north), Marylebone (5 miles north), Kensington (4 miles north-west), St Pancras (6 miles north) and Shoreditch (7 miles north-east).
Near you in Balham
Typical jobs here are in homes near Oak Lodge School, Wandsworth Common and The Bedford pub and the streets around them. There’s a railway station in Balham itself: Balham station. Other landmarks nearby include St James' Hospital (0.5 miles west) and London Sewing Machine Museum (0.6 miles south-west). For a walk, there’s Knight's Hill and Battersea Park Lake.
Quotes for window mastic in Balham
The price is agreed before any work begins. It takes into account:
- Any mould that needs treating
- When we can work, for business premises
- How many rooms, windows or areas are involved
- The size of the job
We don’t show prices on the website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or drop us an email.
What to tell us for a quote
You do not need to know the technical terms. Just tell us:
- Where the property is
- What the problem is, such as mould, gaps, leaks or cracking
- A few photos by email, if you can
- How many joints, rooms or windows are involved
If you’re in Balham and need window mastic, phone 0345 464 0079 or email us. Tell us what the problem is and where, and you’ll get a clear quote before work begins.