Greater London · England
Sand mastic for sash & case windows in Coombe, Greater London
We cover Coombe for traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Tired mastic found when preparing windows for paint
- Cement or filler used on old window joints that has cracked
- Wind and rain getting in round a sash window
Why it’s worth doing now in Coombe
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic is the like-for-like choice and that can be important for listed homes. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Coombe, the repair is bigger than the sealant job would have been.
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
Why choose Mr Mastic in Coombe
- Rated 4.9 stars on Google
- Anti-fungal silicone where joints get wet
- Approved under the ARBOMaster scheme
- Every job guaranteed for a year
See our cost guide or our reviews.
Sand mastic in Coombe, done properly
On many period windows, sand mastic looks right and suits the building. On modern frames we’d normally use a flexible sealant and we’ll explain which is best for yours. We work on stone surrounds, timber door frames and brick reveals, and common reasons people get in touch are modern sealant on a period surround and mastic round period door frames that has failed.
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, which is when draughts and damp patches appear in homes in Coombe.
Whatever the size of the job, you get the same one-year guarantee in Coombe and across Greater London.
- Where
- Coombe (CR0, CR2, CR9)
- Wider area
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Should I try it myself first?
A careful DIYer can reseal a simple joint, 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.
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.
How the visit works
There’s no need to move everything out, just the space around the work. Everything nearby is protected, and the job takes anything from a few hours to a full day, depending on how many windows for a typical 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 the window surrounds and agree which joints need renewing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic isn’t too thick.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- We dress the surface so it sits neatly against the masonry.
Getting ready for the visit
- For indoor joints, keep the area dry beforehand if you can
- Clear the area around the work
- Tell us about any water getting in
Ask for a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job.
Related advice
Coombe: your questions answered
Can parking be tricky for a visit in Coombe?
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.
Do you cover Coombe for sand mastic?
Yes. Our work covers London and the South East, and Coombe is part of that. Just call 0345 464 0079 or email us with a few details of the job.
Do the sealants smell?
Some sealants have a smell while they cure, which fades as it sets. Opening a window helps.
Which products do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We explain the product when we quote.
Do I need to be at home?
We need access to the joints, so we will agree that with you when we book. For inside work, that normally means someone being in.
Is it possible to take out silicone and use sand mastic instead?
In most cases. We remove the silicone and clean the joint before the sand mastic goes in.
Is it OK to seal over old sealant?
No. We remove every bit of old sealant first, so the new sealant bonds properly.
Can I choose the sealant colour?
Yes. White, clear and grey are common, and other colours are available for many products, and we agree the colour with you before work begins.
How we quote for sand mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The number of rooms or windows
- When we can work, for business premises
- The size of the job
- The old material and how stubborn it is
The cost depends on the size of the job, how hard the old material is to remove and access to the work. You’ll have a clear quote before any work starts, so you know where you stand.
What to tell us for a quote
Before you ask for a quote, have a think about:
- Where the job is, and your postcode
- Any access issues, like height or stairs
- If someone has resealed it before
- The problem you’ve noticed
For sand mastic in Coombe, ring 0345 464 0079 or drop us an email. Tell us what the problem is and where, and you will get a clear quote before work begins.
What sealant work can’t fix
Some problems need a builder, plumber or other trade rather than us:
- Sash cords, weights and draught-proofing of the sashes
- Planning or listed building consent (your local planning authority decides)
- Cracked or broken glass
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly.
Joints and surfaces we work on
- Timber door frames
- Period & listed homes
- Stone surrounds
- Tenement windows
- Sash and case windows
- Brick reveals
Windows and doors in Coombe
In a converted house or block, who looks after the windows depends on the lease, 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 live in an older home near Church Hall United Reformed Church Of St Paul, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Coombe is in London, so parking needs planning: let us know about parking bays, permits or a driveway. Letting a property close to South Croydon station? Then any sash windows need sound mastic to keep draughts and rain out.
Coombe is about 1 mile east of Croydon, in Greater London. Wherever you are in the CR0 postcode area, our applicators can take on sand mastic. 764 places in Greater London are on our list, large and small. We also work in London, around 9 miles away.
Here we cover the CR0, CR2 and CR9 postcode area for sand mastic. You’ll find streets such as Oaks Road, Coombe Road and Coombe Lane, all of which we cover. If you are just outside Coombe, we cover Croydon (1 mile west), Addiscombe (1 mile north), South Croydon (1 mile south-west), Shirley Oaks (1 mile north-east) and Shirley (1 mile north-east). We also work in nearby towns such as London (9 miles north), City of Westminster (11 miles north), Marylebone (11 miles north), Kensington (11 miles north-west), St Pancras (11 miles north) and Shoreditch (11 miles north).
Landmarks near Coombe
We work in homes and buildings around Coombe Lodge pub, Royal Russell School and St Peter's Primary School. The closest station to Coombe is South Croydon station, about 1 mile west. Other landmarks nearby include St George's Walk (1.4 miles north-west) and Croydon Airport Visitor Centre (2.1 miles west). Open spaces near Coombe include Bramley Bank and Duppas Hill.
Nearby places to Coombe
Also in Coombe
For landlords 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.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
What the job involves on each surface
Timber door frames
Door frames get knocked and soaked and the mastic can crack early. We rake it out and renew it.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.