Greater London · England
Window & door mastic in West Dulwich, Greater London
Mastic around window and door frames, sills and patio doors for homes and businesses in West Dulwich and across Greater London. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Mastic that’s falling out in pieces
- Cracked or shrunken mastic around the frame
- Gaps where the sill meets the wall
Window mastic in West Dulwich
The new joint doesn’t have to be white. We can seal in white, brown, anthracite grey, black or clear, so the line suits the frame instead of standing out. We work on uPVC windows, window sills and composite doors, and the jobs we see most are rushed sealant from a window installation and hard, cracked sealant around 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, letting in draughts and water.
Big or small, it’s backed by our one-year guarantee in West Dulwich and across Greater London.
- Location
- West Dulwich (SE21, SE27, SE19)
- Region
- Greater London
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What sealant work cannot fix
It helps to know what we can’t do:
- Draughts through the window seals rather than the frame
- Damp problems in the wall away from the window
- Soft or decayed wood in the frame
If you’re not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer.
What we seal
- Window sills
- Patio & French doors
- Composite doors
- Timber windows & doors
- uPVC windows
- Aluminium frames
DIY sealant or a professional job?
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
Why it’s worth doing now in West Dulwich
Getting a straight, even bead on an outside frame takes practice, especially upstairs. A professional job is cut out properly, backed where needed and finished neatly, using a product chosen for the frame and wall. Converted houses in London often have a bathroom above someone else’s living room, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Putting it right early is much less trouble.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed. Call for a quick quote and we will go through it with you.
What you get with us
- White, clear, grey or coloured to suit, where the product allows
- Approved under the ARBOMaster scheme
- 12-month guarantee on every job
- Trusted Arbo and Everbuild sealants
Your questions about window mastic in West Dulwich
Can you help a landlord with a rental near Sydenham Hill station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we’ll give you a clear price.
Is parking an issue for window mastic in West Dulwich?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Is it messy?
Not at all. The area is protected while we work and cleaned up afterwards.
Can you do upstairs windows?
Usually, yes. We plan safe access before the job, so mention the height and anything in the way.
Do the sealants smell?
There can be a smell while the sealant cures, which fades as it sets. Opening a window helps.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we are part of it.
Will the old sealant be removed?
Yes, always, and completely. New sealant won’t bond properly to old, so any old material comes out before anything new goes in.
Does someone need to be in?
For indoor joints, yes, someone needs to let us in. Once we’ve agreed the job, you don’t need to watch us work.
How the visit works
All our tools and materials come with us in the van, so there’s nothing for you to buy. After a quick look at the joints together, we protect the area and start. Most jobs take a morning for a couple of windows and a door. In West Dulwich, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We check each frame and agree which ones need doing.
- We remove the old mastic and clean the frame and the wall.
- Where gaps are deep, backing rod goes in first.
- A flexible, weatherproof sealant is applied in a colour to suit the frame.
- Finally we tidy up and check each joint.
Getting ready for the visit
- Keep pets and children clear of the area while we work
- Try not to wet indoor joints just before the visit
- Clear items away from the joints we’re working on
Ask for a quote
For window mastic in West Dulwich, phone 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we will agree the price before any work begins.
Advice
Common problems we fix in West Dulwich
Older frames were often sealed with products that set hard. Once it’s rigid, every bit of frame movement pulls at it, leaving a hairline gap down one side.
The problems people normally mention when they call include:
- Cold air getting in at the frame edge
- Draughty joints inside around the window
- Gaps left after new windows were fitted
- Cracked sealant at the sill ends
West Dulwich is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Before you book anyone
- How hidden problems are handled
- What the quote includes, VAT included or not
- Whether they’re fully insured
- What preparation is included
Windows and doors in West Dulwich
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. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book.
If you let a flat or house near Sydenham Hill station, renewing tired window mastic between tenants heads off draught and damp complaints. If you look after a building such as Dulwich Wood Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
West Dulwich is about 1 mile north-east of West Norwood, in Greater London. If you need window mastic in West Dulwich, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover Greater London, West Dulwich included. Our Greater London coverage runs to 764 places, West Dulwich among them.
All of SE21, SE27 and SE19 is covered for window mastic, from the main roads to the quietest streets. You will find streets such as Berry Lane, Clive Road and Myton Road, and we cover them all. Main roads around West Dulwich include the A2199, so getting to you is simple. Neighbouring places we cover for window mastic include Sydenham Hill (1 mile east), West Norwood (1 mile south-west), Gipsy Hill (1 mile south), Dulwich (1 mile north) and Upper Norwood (1 mile south). Further out, we also cover London (5 miles north), City of Westminster (6 miles north-west), Marylebone (6 miles north-west), Kensington (7 miles north-west), St Pancras (7 miles north) and Shoreditch (6 miles north).
Around West Dulwich
Typical jobs here are in homes near The Wood House, Dulwich Prep & Senior and Kingsdale Foundation School and the streets around them. There’s a railway station in West Dulwich itself: Sydenham Hill station. Nearby you will also find British Vintage Wireless And Television Museum (under half a mile west) and St Christopher's Hospice (1.3 miles south-east). Open spaces near West Dulwich include Battersea Park Lake and Dulwich Upper Wood.
Towns and villages near West Dulwich
Also in West Dulwich
Looking after it afterwards
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Make sure the drainage slots are not blocked
- Air rooms to keep condensation down around windows
- Repaint timber before it’s bare
- Paint up to the joint, not over it
On timber frames, keep the paintwork in good order, since wood that gets wet swells and shrinks more. Keep paint off the silicone itself.
On timber windows, water behind the joint can lead to rot. Rotten timber needs a joiner, not a sealant, so early resealing is worth it.
What affects the cost of window mastic
For a quick quote, just ask. The main things that affect it are:
- The number and length of the joints
- Access and height
- Any working-time requirements on site
- Whether there’s mould to deal with
The cost depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start.
Asking for a quote
A few details help us give you an accurate quote. When you ask for a quote, tell us:
- The address or postcode of the job
- Access, such as stairs, a lift or height
- How many joints, rooms or windows are involved
- What’s wrong with the joints now
Getting a quote is simple: let us know the job and the location. A few pictures by email make the job easier to understand.