Greater London · England
Window Mastic in Southwark
Window and door frames in Southwark need attention? We cut out the old, prepare the joints and apply the right sealant.
- Cold air getting in at the frame edge
- Cracked sealant at the sill ends
- Draughty joints inside around the window
Different surfaces, different methods
Patio & French doors
Water at the foot of a door frame is not always the mastic: blocked drain slots, worn brush seals and threshold details can let water in too. We check before we reseal.
Composite doors
A composite door generally sits in a plastic outer frame, so its perimeter joint is sealed much like a window. The bead is colour-matched to the frame.
How we handle window mastic in Southwark
Whether it’s one leaking patio door or every frame on the house, the work is priced before anything is done. To get one, phone 0345 464 0079 or send us an email with the number of frames and any access details for window mastic in Southwark. We work on composite doors, uPVC windows and window sills, and people most often call us about sealant in the wrong colour for the frame and rain getting in at the frame or under the sill.
London’s Victorian and Edwardian terraces were built with timber sash windows, and many still have them or their replacements. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in Southwark as anywhere.
Each job carries a 12-month guarantee, large or small.
- Where
- Southwark (SE1, SE11)
- Wider area
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
How we quote for window mastic
The quote reflects the job in front of us. We take into account:
- The number and length of the joints
- The old material and how stubborn it is
- Working hours on commercial sites
- The number of rooms or windows
We don’t show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
What we need to know
When you call or email, these details help:
- Access, such as stairs, a lift or height
- A few photos by email, if you can
- Whether it has been sealed before
- The address or postcode of the job
We quote each job on its own, so start by telling us what you need. Simply phone 0345 464 0079 or send us an email and describe the job and send photos if you have them.
When it is not the sealant
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Misting between the panes of a double-glazed unit (that needs a new unit)
- Damp coming through the wall itself rather than the frame joint
- Soft or decayed wood in the frame
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we’ll tell you honestly before booking.
What we seal
- Window sills
- uPVC windows
- Timber windows & doors
- Patio & French doors
- Aluminium frames
- Composite doors
Do you need window mastic in Southwark?
Timber windows bring their own problems. Old mastic gets painted over and cracks under the paint, and the wood moves with damp as well as heat.
The most common problems we see are:
- Old mastic that has gone black or come away
- Cold air getting in at the frame edge
- Gaps between the frame and the inside reveal
- Gaps left after new windows were fitted
In the older streets around Borough Welsh Congregational Chapel, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Comparing quotes
- Is VAT in the price?
- What product goes in the joint
- Whether they seal over old material or remove it
- How long the guarantee is
Why it’s worth doing now in Southwark
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished, and it’s easier while the walls are being worked on anyway. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
Why book with us
- Fully insured
- Tidy, careful work
- Quality sealants from Arbo and Everbuild
- White, clear, grey or another colour, product permitting
Read our cost guide and customer reviews.
Work for landlords, hotels and businesses
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can go on one quote.
The process
At the end, we look at the finished work together. The work normally takes a morning for a couple of windows and a door, depending on the size of the job. For a job in Southwark, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- First, we go round the frames with you and agree the list.
- 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.
- Every joint is tooled smooth and checked before we leave.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- Clear the area around the work
- For business premises, tell us about site rules or sign-in
Get a quote
Getting a quote is simple: let us know the job and the location, and roughly how big it is. A few pictures by email make the job easier to understand, and we’ll take it from there.
Advice
Places near Southwark
Other services in Southwark
Frames and glazing around Southwark
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
If you look after a building such as Charles Dickens Primary School, larger buildings have plenty of frames, and the mastic around each one ages. For landlords with property near Elephant & Castle station, sound mastic around windows and doors keeps out the draughts and damp that tenants notice first.
Southwark is about 0 miles north-west of London, in Greater London. Across the SE1 area, our applicators can take on window mastic. Southwark is one of 764 places in Greater London where we work.
We cover every part of SE1 and SE11 for window mastic. We cover properties on Borough Square, Trinity Church Square and Merrick Square and the roads around them. Being close to the A300 and B240, Southwark is easy for our applicators to reach. If you’re just outside Southwark, we cover Tower Hill (1 mile north-east), City of London (1 mile north), Aldgate (1 mile north-east), Bishopsgate (1 mile north-east) and Barbican Estate (1 mile north). Within a short drive, we also cover City of Westminster (3 miles west), Kensington (5 miles west), Walthamstow (7 miles north-east), Hampstead (5 miles north-west), Ruislip (14 miles west) and Brompton (3 miles west).
What’s near Southwark
Typical jobs here are in homes near London School of Musical Theatre, Little Dorrit's Playground and St Mary-at-Hill and the streets around them. Nearby too are Ark Globe Academy (within half a mile south-east), The BFI Reuben Library (0.9 miles north-west) and The Gladstone Arms (less than half a mile north-east). For rail, the closest station is Elephant & Castle station, roughly 0.5 miles south of the centre. Well-known places in the area include Gabriel's Wharf (0.7 miles north-west) and Baynard's Castle (0.8 miles north). Not far away are Ludgate Hill and Bellenden Road Nature Garden.
Southwark: your questions answered
I let a flat near Elephant & Castle station. Can you help?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear price.
Is Southwark in your area for window mastic?
Yes. Our work covers London and the South East, and Southwark is part of that. You can call 0345 464 0079 or email us and tell us what needs doing.
Can I add another job to the visit?
Of course. Doing several areas at once is generally more efficient.
Where do you work from?
We’re a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises. Working times can be discussed when we quote.
Does the work come with a guarantee?
Yes. All our work carries a 12-month guarantee, and we’re ARBOMaster approved applicators.
Will resealing my frames help with draughts?
Yes, where the draught is at the frame edge. We find where the air is coming from before we reseal.
How much does window mastic cost in Southwark?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote and we will talk you through it.