Greater London · England
Window & door mastic in Crofton, Greater London
Professional window mastic in and around Crofton, with old sealant always removed completely and a 12-month guarantee.
- White mastic on grey or black frames
- Leaking joints at the ends of sills
- Rain getting in at the frame or under the sill
About our window mastic in Crofton
Mr Mastic’s applicators have more than 20 years’ experience with window and door sealants. We’re ARBOMaster approved and fully insured, and every job is covered by a 12-month guarantee. If you have untidy mastic left by window fitters and old mastic that has gone black or come away, we can help, on patio & French doors, composite doors and uPVC windows 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 Crofton as anywhere.
Whatever the size of the job, you get the same 12-month guarantee.
- Where
- Crofton (BR6, BR5)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How it works
At the end, we look at the finished work together. The visit itself generally takes a few hours for a few frames, or a day or more for a whole house, depending on the size of the job. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- We check each frame and agree which ones need doing.
- 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.
- Every joint is checked before we leave.
Before we arrive
- Where the joints are inside, avoid wetting them before we arrive
- Clear the area around the work
- Let us know if you’ve seen damp or leaks
Ask for a quote
Want a quote for window mastic? Please call 0345 464 0079 or send us an email and tell us about the job. We will explain what we’d do and give you a clear price before work begins.
Related advice
Crofton questions
Can you do window mastic in Crofton?
Yes. We work across London and the South East, and Crofton is part of that. Just phone 0345 464 0079 or email us with a few details of the job.
Is parking an issue for window mastic in Crofton?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. The visit is then planned around what’s available.
Can you work on commercial sites?
Yes. Hotels, offices and other businesses use us.
Should I try DIY first?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Will resealing my frames help with draughts?
Yes, if the air is getting in around the frame. If it’s coming through the window seals, we’ll tell you.
How many windows can you do in a day?
Allow a few hours for a few frames, or a day or more for a whole house. Access and how stubborn the old mastic is affect the time most.
How long should I leave it?
It depends on the product and the temperature. Before we leave, we’ll tell you the cure time.
Does someone need to be in?
It depends on the job. For work indoors, someone needs to let us in, and for outside work we’ll agree access with you when we book.
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Paint up to the joint, not over it
- Clean frames with a soft cloth and soapy water
- Walk round the house once a year and look at the joints
- Avoid harsh chemicals near the mastic
Timber frames need their paint kept up, because bare, wet timber moves more and pulls at the joint. Keep paint off the silicone itself.
Signs to watch for: cracks in the mastic, gaps you can see light through, damp on the reveal or mould around the inside of the frame. If you notice one, it’s time to get the joint looked at.
Places near Crofton
Also in Crofton
What affects the quote in Crofton
For a quick quote, just ask. What matters most is:
- The type of sealant required
- When we can work, for business premises
- How easy the joints are to reach
- The number and length of the joints
The cost reflects the work involved, not guesswork. That’s why we ask about the job first.
Asking for a quote
The more you tell us, the more accurate the quote. When you get in contact, it helps to mention:
- The type of property
- If someone has resealed it before
- Any access issues, like height or stairs
- What the problem is, such as mould, gaps, leaks or cracking
To get a quote, call 0345 464 0079 or email us and tell us where the job is and what the problem looks like. You’ll have a clear quote before we start.
What happens if it’s left?
The work is quick compared with the damage it prevents: it takes a few hours for a handful of frames, longer for a whole house. Wait for damp to appear and there may be plaster and decorating to sort out too. In a flat in Crofton, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Homes and businesses are quoted the same way: the amount of work, how we reach it and what it needs, along with when we can work on site. Call for a quick quote and we’ll explain what it covers.
Why book with us
- We never seal over old sealant
- A sealant colour to suit the surroundings
- Full insurance on every job
- We leave the area clean and tidy
Take a look at how sealant jobs are priced or our reviews.
Windows and doors in Crofton
In London conversions and blocks, the lease decides who is responsible for the frames, so check that before booking. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you look after a building such as Crofton Infant School, the mastic around its windows and doors needs looking after like any other building’s. As a London address, Crofton can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Crofton is about 1 mile south-west of Orpington, in Greater London. Crofton gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Across Greater London, we cover 764 places, and Crofton is one of them. There’s also a page for London, about 11 miles away.
Postcode districts we cover here for window mastic: BR6 and BR5. We cover properties on Grange Road, Reed Avenue and Gumping Road and the roads around them. If you’re just outside Crofton, we cover Broom Hill (1 mile north-east), Locksbottom (1 mile west), Petts Wood (1 mile north), Farnborough (1 mile south) and Green Street Green (2 miles south). Within a short drive, we also cover London (11 miles north-west), City of Westminster (14 miles north-west), Marylebone (14 miles north-west), Kensington (15 miles north-west), St Pancras (14 miles north-west) and Shoreditch (12 miles north-west).
Around Crofton
Around Crofton, our work takes us to homes and buildings near The Priory School, Newstead Wood School and The Maxwell pub. Crofton has its own railway station: Orpington station. Other landmarks nearby include Orpington Hospital (1.1 miles south-east) and Crofton Roman Villa (under half a mile south-east). Open spaces near Crofton include Summer Hill and The Warren.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too in Crofton and across Greater London. Several sites can go on one quote, and we are fully insured.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Common problems we fix in Crofton
Water runs down the glass onto the sill, and the ends of the sill, where it meets the wall, are where it gets in. Failed sealant there lets rain into the wall or behind the frame.
It’s worth asking for a quote if you see:
- Gaps between the frame and the inside reveal
- Old mastic that has gone black or come away
- Mastic that has split away from the wall
- Rushed sealant from a window installation
If you live in an older home near Church of Jesus Christ of Latter-Day Saints, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Comparing quotes
- When the joint can take water or movement
- Which sealant they’ll use, and why
- Whether VAT is included
- How the colour is chosen
Can I do it myself?
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.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.