Greater London · England
Window Mastic in South Croydon
Window and door frames in South Croydon need attention? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Black, perished sealant on frames
- Whistling draughts around closed windows
- Gaps between the frame and the inside reveal
About our window mastic in South Croydon
Around South Croydon we seal all kinds of frames: uPVC, aluminium, timber and composite, along with patio doors, French doors and sills. The sealant is chosen to suit the frame material and the wall. If you have gaps where the sill meets the wall and untidy mastic left by window fitters, we can help, on timber windows & doors, patio & French doors and window sills alike.
Much of London’s older housing was built with timber sash windows, some still in place and some long since replaced. Either way, the mastic between frame and brickwork is what stops draughts and rain getting in, in South Croydon as anywhere.
Every job comes with our one-year guarantee.
- Where
- South Croydon (CR2, CR8, CR0)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Your questions about window mastic in South Croydon
Can you help a landlord with a rental near Sanderstead station?
Yes, we work for landlords and letting agents. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Do you cover South Croydon for window mastic?
Yes, South Croydon is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What sealant do you use?
It depends on the joint: sanitary silicone where it gets wet, and sealants suited to movement or weather elsewhere. Brands we use include Arbo and Everbuild.
Does the work come with a guarantee?
Yes. Our 12-month guarantee covers every job.
What information do you need?
The location, the problem and the rough size of the job. If you can, email a few pictures.
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.
Is it OK to seal over old sealant?
No. New silicone will not bond to old silicone, and it traps any mould or water underneath. It all has to come out first.
Should I try it myself first?
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
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 does not work out, we can still put it right.
Why deal with it now?
Getting a straight, even bead on an outside frame takes practice, especially on upper floors. We cut out properly, back deep gaps and tool every joint neatly, using a product chosen for the frame and wall. 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.
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you’re not sure whether it needs doing, ring 0345 464 0079 or drop us an email and we’ll give you an honest view and a quote.
What you get with us
- A 12-month guarantee on all work
- An ARBOMaster approved applicator
- Sealant colour chosen to suit
- Anti-fungal silicone where joints get wet
Read what affects the cost or what customers say.
What sealant work cannot fix
New sealant can’t fix everything, and we’ll tell you before we start. It will not solve:
- Condensation trapped between the panes
- Worn gaskets, brush seals or a door that has dropped
- A sash or casement that won’t close properly
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly before you book.
Joints and surfaces we work on
- uPVC windows
- Composite doors
- Window sills
- Patio & French doors
- Timber windows & doors
- Aluminium frames
Quotes for window mastic in South Croydon
There’s no set price list. The quote depends on:
- Any working-time requirements on site
- The number and length of the joints
- Mould in or behind the old joints
- How easy the joints are to reach
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first.
Helping us quote
Photos help, but a description is a good start. Try to tell us:
- If someone has resealed it before
- How many joints, rooms or windows are involved
- If it’s domestic, commercial or a hotel
- Where the property is
Every job is quoted individually. Simply call 0345 464 0079 or email us and describe the job and send pictures if you have them.
Do you need window mastic in South Croydon?
A lot of older mastic was never designed to stay flexible. Once it has hardened, the frame’s movement tears it from the wall, and a gap opens along one edge.
It’s worth asking for a quote if you see:
- Water coming in at the bottom corners of a door
- Mastic that is falling out in pieces
- Cracked internal joints between frame and plaster
- Gaps where the sill meets the wall
For an older house near a landmark such as Church of St Augustine, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Before you book anyone
- Are they insured?
- What preparation is included
- How long to leave it before use
- What guarantee comes with the work
Aftercare tips
So the new joints stay in good condition:
- Keep drainage slots and sill grooves clear
- Keep paint off silicone joints
- Walk round the house once a year and look at the joints
- Keep timber frames painted
Keep sill grooves and drainage slots clear, so rain drains out rather than building up at the sealant.
Water trapped behind a failed joint can start rot in timber frames and sills. Once wood has rotted, it needs repair before it can be sealed, so early resealing is worth it.
Towns and villages near South Croydon
Also in South Croydon
Windows and doors in South Croydon
Historic houses like Addington Palace (about 2.4 miles east) are a reminder that the area around South Croydon has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
As a London address, South Croydon can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. If you look after a building such as Purley Oaks Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
South Croydon is about 1 mile south of Croydon, in Greater London. Across the CR2 area, our applicators can take on window mastic. South Croydon is one of 764 places in Greater London we cover for window mastic. There’s also a page for London, roughly 10 miles from South Croydon.
Our applicators cover all of the CR2, CR8 and CR0 postcode area for window mastic and the streets around it. Local streets include Edgar Road, Bynes Road and Grange Road, all of which we cover. We also cover Croydon (1 mile north), Coombe (1 mile north-east), Sanderstead (1 mile south-east), Riddlesdown (2 miles south) and Selsdon (2 miles east). Further out, we also cover London (10 miles north), City of Westminster (11 miles north), Marylebone (12 miles north), Kensington (11 miles north-west), St Pancras (12 miles north) and Shoreditch (12 miles north).
Near you in South Croydon
Locally, jobs take us to homes and businesses close to The Purley Arms, Harris Academy Purley and Duppas Hill, among other places. South Croydon has its own railway station: Sanderstead station. Well-known places in the area include Purley War Memorial Hospital (1.2 miles south-west) and Croydon Airport Visitor Centre (1 mile west). Open spaces near South Croydon include Roundshaw Downs and Duppas Hill.
What we do, step by step
Good joint work is mostly preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes most of a day for a typical house, less for a few frames. In South Croydon, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- We start by checking each window and door with you.
- The old mastic is cut out and the surfaces cleaned back.
- Where gaps are deep, backing rod goes in first.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- We clear up and check every joint is fully closed.
Before we arrive
- Tell us about access, such as stairs, a lift or high-level joints
- On commercial sites, let us know about site rules
- Clear items away from the joints we’re working on
Ask for a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email photos if that’s easy.