Greater London · England
Window Mastic in Stockwell
Window mastic across Stockwell and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- White mastic on grey or black frames
- Gaps where the sill meets the wall
- Cracked or shrunken mastic around the frame
How to look after the new joints
To keep the joints looking good and working properly:
- Paint up to the joint, not over it
- Ventilate rooms so frames do not stay wet inside
- Look round the frames every year or so
- Keep drainage slots and sill grooves clear
Most silicone sealants will not take paint, so if you’re planning to paint the frames or walls, tell us beforehand. There are paintable sealants for joints that need it.
On timber windows, water behind the joint can lead to rot. Once wood has rotted, it needs repair before it can be sealed, so early resealing is worth it.
Window mastic in Stockwell
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. That is why the joint needs a flexible, low-modulus sealant rather than something rigid. We work on uPVC windows, aluminium frames and window sills, and people most often call us about whistling draughts around closed windows and hard, cracked sealant around windows.
London homes have every kind of window, from timber sashes in period terraces to aluminium and uPVC in newer blocks. Over the years, the sealant around them shrinks, cracks and pulls away, which is when draughts and damp patches appear in homes in Stockwell.
Every job comes with a one-year guarantee.
- Place
- Stockwell (SW9, SW4, SW8)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How the job changes by surface
Patio & French doors
Door frames take knocks and movement every time the doors are used. A flexible sealant copes with that without cracking.
Window sills
Stone and concrete sills have their own joints, and the joint under the frame can let rain run behind. Those are sealed with a product suited to stone or concrete.
Towns and villages near Stockwell
Other services in Stockwell
Work for landlords, hotels and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
In hotels, rooms out of use cost money, so we plan the work room by room. We have worked in hotels as well as homes and businesses.
How the visit works
We keep the work tidy and contained to the area we’re working on, so you can carry on as normal. Expect the work to take anything from an hour or two to a full day, depending on how many frames there are. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Stockwell. It helps if you can point us to a visitor permit or a bay close to the door.
- First, we go round the frames with you and agree the list.
- We remove the old mastic and clean the frame edge and wall.
- 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.
Preparing for the visit
- Let us know if you’ve seen damp or leaks
- Tell us about access, such as stairs, a lift or high-level joints
- Tell us if parking is tricky
How to get a quote
Asking for a quote is easy: tell us what needs doing and where and its rough size. A few photos by email make the job easier to understand, and we’ll take it from there.
Read more
DIY sealant or a professional job?
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
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.
What affects the cost of window mastic
The quote reflects the job in front of us. We take into account:
- Working hours on commercial sites
- Mould in or behind the old joints
- Access and height
- The size of the job
We do not show prices on the website, because each job is priced on what it involves. For a quick quote, please phone 0345 464 0079 or email us and we will talk you through it.
Helping us quote
When you call or email, it’s useful to know:
- Where the job is, and your postcode
- The rough size of the job
- How we’d reach the joints
- Whether it’s a home or a business
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we will explain what’s involved before giving you a price.
When something else is needed
We won’t take on work that won’t last, so here’s what sealant cannot put right:
- Damp coming through the wall itself rather than the frame joint
- Condensation trapped between the panes
- A door that needs adjusting, rehanging or new seals
If you’re 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
- Aluminium frames
- Window sills
- Composite doors
- Timber windows & doors
- Patio & French doors
- uPVC windows
Common questions in Stockwell
Is parking an issue for window mastic in Stockwell?
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 Brixton station?
Yes, rental work is part of what we do. You can call 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Can you reach windows above the ground floor?
Yes, where it’s safe. Higher or awkward frames may need extra access, and we will confirm what’s needed.
How long before the joint can be used?
That depends on the sealant used, so please follow the time we give you when we finish.
Can I do it myself?
That depends on the joint. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
Can you seal the gap between the frame and the plaster indoors?
Yes. Inside, the joint between frame and plaster is sealed neatly.
Can I paint over the new sealant?
Not normally, if it’s silicone. Tell us your decorating plans and we will pick a sealant to suit.
Can resealing stop a draught around my window?
Often, yes. Air often gets in between the frame and the wall, and sealing the inside and outside joints closes that path.
Window mastic in Stockwell: local notes
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Carlyle's House (about 2.4 miles north-west) nearby, there’s older building stock in the area around Stockwell as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
Rented homes near Brixton station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. For site and facilities teams at buildings such as St Andrew's Church of England Primary School, larger buildings have plenty of frames, and the mastic around each one ages. As a London address, Stockwell can be tricky for parking: let us know about parking bays, permits or a driveway.
Stockwell is about 2 miles south-west of London, in Greater London. Homes, rented property, offices and hotels in Stockwell can book us for window mastic. Every job comes with our 12-month guarantee. Stockwell is one of 764 places in Greater London we cover.
Work in SW9, SW4 and SW8 is quoted and booked the same way as anywhere else. You will find streets such as Kay Road, West Road and Cato Road, all of which we cover. Stockwell is on the A203 and A2217, so it’s easy for us to get to with everything needed for window mastic. We also cover the places around Stockwell: Little Portugal (1 mile north), Angell Town (1 mile east), North Brixton (1 mile north-east), South Lambeth (1 mile north) and Clapham (1 mile west). Further out, we also cover City of Westminster (3 miles north-west), Marylebone (4 miles north), Kensington (4 miles north-west), St Pancras (4 miles north), Shoreditch (4 miles north-east) and Walthamstow (9 miles north-east).
Landmarks near Stockwell
Locally, jobs take us to homes and businesses close to Max Roach Park, Lansdowne School and The Marquess Of Lorne Public House. The closest station to Stockwell is Brixton station, about 0.5 miles south-east of the centre. A little further out are Gabriel's Wharf (2.8 miles north) and Baynard's Castle (3.1 miles north). Open spaces near Stockwell include Knight's Hill and Centre for Wildlife Gardening.