Greater London · England
Ashburton Window Mastic
Mastic around window and door frames, sills and patio doors for homeowners, landlords and businesses in Ashburton. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Gaps left after new windows were fitted
- Cracked sealant at the sill ends
- Draughts coming in around windows and doors
Different surfaces, different methods
Timber windows & doors
Soft or rotten wood can’t be sealed successfully. We will point out any rot we find, as a joiner will need to deal with it.
Patio & French doors
Not every patio door leak is a mastic problem: worn seals, blocked drainage slots or a poor threshold detail can be the cause. We look for the cause first.
Window mastic in Ashburton
From a single sill to a whole house of windows, the work is priced before anything is done. Just phone 0345 464 0079 or email us and tell us how many frames there are and how they’re reached for window mastic in Ashburton. If you’re dealing with black, perished sealant on frames and cracked or shrunken mastic around the frame, we can help.
Many London homes are flats, with windows high above the street. Who looks after the outside of the frames can depend on the lease, so check that first, and access in Ashburton is something to talk through when you book.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Ashburton (CR0, SE25, CR9)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Towns and villages near Ashburton
Also in Ashburton
How we quote for window mastic
Your quote is based on your job. We take into account:
- The product the joint needs
- The old material and how stubborn it is
- The size of the job
- How many rooms, windows or areas are involved
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
What to tell us for a quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Photos by email, if that is easy
- Any access issues, like height or stairs
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we’ll talk you through the work.
What we’re called out for in Ashburton
Plenty of failed mastic was poorly applied in the first place. Sealant run over dust, wet brick or loose mortar didn’t grip properly, so it comes away long before its time.
The most common problems we see are:
- Gaps left after new windows were fitted
- Draughty joints inside around the window
- Gaps where the sill meets the wall
- Cracked or shrunken mastic around the frame
For an older house near a landmark such as Church of St Luke, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Questions to ask before you book
- Who does the work, and how experienced they are
- How hidden problems are handled
- Whether they’re fully insured
- How the joint is cleaned and prepared
What happens if it’s left?
Once mastic fails, rain can get between the frame and the wall. Left long enough, it can stain inside walls, spoil plaster and rot wooden frames. Resealing now is a small job by comparison. In a flat in Ashburton, failed sealant seldom stays inside your own four walls: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
No two jobs are quite the same, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Why book with us
- Anti-fungal sanitary silicone in wet areas
- 180+ five-star Google reviews
- Sealant colour chosen to suit
- Approved under the ARBOMaster scheme
Take a look at our cost guide or what customers say.
DIY versus a professional finish
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.
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Aftercare tips
To keep the joints looking good and working properly:
- Do not aim a pressure washer at the joints
- Paint up to the joint, not over it
- Clean frames with a soft cloth and soapy water
- Look round the frames every year or so
Keep sill grooves and drainage slots clear, so water can run away instead of sitting against the joint.
A small gap around a frame only grows. As the old mastic shrinks further, more air gets through, and a cold room gets colder. Resealing closes it.
What window mastic looks like in Ashburton
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. In a converted house or block, who looks after the windows depends on the lease, so check that before booking.
Rented homes near Norwood Junction station change hands often, and sound mastic around windows and doors keeps out the draughts and damp that tenants notice first. Schools such as St Thomas Becket Catholic Primary School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
Ashburton is about 6 miles south of New Cross, in Greater London. Our applicators cover window mastic for householders, landlords and businesses in Ashburton. Our area takes in 764 places across Greater London, from the larger towns to small villages. London is on our list too, around 8 miles away.
Jobs for window mastic in CR0, SE25 and CR9 works the same way as everywhere else we cover. If you need window mastic at a property on Long Lane, Tudor Road and Coe Avenue or a nearby road, our applicators can take on the job. We also cover Woodside (1 mile north), Addiscombe (1 mile south), Shirley Oaks (1 mile south-east), Monks Orchard (1 mile south-east) and Shirley (1 mile south-east). Larger places within reach include London (8 miles north), City of Westminster (9 miles north-west), Marylebone (10 miles north), Kensington (10 miles north-west), St Pancras (10 miles north) and Shoreditch (10 miles north).
Around Ashburton
Typical jobs here are in homes near Oasis Academy Shirley Park, Ashburton Park and The Beehive pub, among other places. Ashburton’s nearest station is Norwood Junction station, about 0.7 miles north-west of the centre. Nearby you will also find National Psychosis Unit (1.7 miles east) and Whitgift Centre (1.6 miles south-west). Open spaces near Ashburton include Duppas Hill and Bramley Bank.
What we do, step by step
There is not much for you to do on the day. Show us the job and we will take it from there. The job generally takes most of a day for a typical house, less for a few frames. In Ashburton, 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.
- First we look at every frame and agree the list.
- Next the failed sealant is cut away and the joint cleaned.
- Deep gaps are filled with backing rod to set the depth.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Finally we tidy up and check each joint.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- Keep children and pets away from the work area
- Mention any sign-in or site rules at work premises
Getting a quote
For a quote, call 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We will send you a clear quote before any work starts.
Related advice
Ashburton questions
Do you work for landlords with property near Norwood Junction station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. You can phone 0345 464 0079 or send us an email with the details for a clear quote.
Is Ashburton in your area for window mastic?
Yes, Ashburton is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or email us and let us know what needs doing, and we’ll give you a clear quote.
Can new window sealant be painted?
It depends on the sealant. Some hybrid sealants can be painted; silicone can’t. Tell us if you are decorating and we will choose accordingly.
Do you have insurance?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Do I have to be there?
It depends on the job. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.
What sealant do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. Brands we use include Arbo and Everbuild.
Can I do it myself?
Some simple jobs can be done by a careful DIYer. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Where is Mr Mastic based?
We’re based in Crawley, and we cover South East England, London and all of Scotland.