Greater London · England
Sand mastic for sash & case windows in Bromley Common, Greater London
Sand mastic in Bromley Common from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Patchy fillers round a sash window
- Gaps round a timber door in stone or brick
- Failed mastic on an exposed elevation
Sand mastic for homes and businesses in Bromley Common
Sand mastic has long been used to fill the joint between timber frames and masonry. It’s made from sand and a linseed-oil-based binder, applied by hand. On older homes, it suits the building far better than silicone. We are often asked to deal with old cement repairs round a window that have failed and weathered mastic on the most exposed windows, across sash and case windows, stone surrounds and brick reveals.
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.
Each job carries a 12-month guarantee, large or small.
- Place
- Bromley Common (BR2, BR1)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Bromley Common questions
Is parking an issue for sand mastic in Bromley Common?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. That way the visit can be planned around it.
Can you do sand mastic in Bromley Common?
Yes, Bromley Common is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and tell us what needs doing, and we will give you a clear quote.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we’ll explain our choice.
Where is Mr Mastic based?
Mr Mastic is based in Crawley. We cover Bromley Common and the rest of Greater London, along with the rest of our area.
Do I need permission for sand mastic on a listed building?
Checking first is sensible. Ask your local planning authority whether consent is needed for listed or conservation-area properties.
Is it possible to paint over sand mastic?
Traditional guidance is not to paint over sand mastic. Ask us before you decorate around it and we will talk you through it.
Can you replace silicone on a period window with sand mastic?
Yes. The silicone is cut out and the joint cleaned, then point it with sand mastic.
What exactly is sand mastic?
Sand mastic is a traditional material for pointing round windows and doors. It combines sand with a linseed-oil-based binder.
What we do, step by step
At the end, we look at the finished work together. The work normally takes anything from a few hours to a full day, depending on how many windows, depending on the amount of work. Parking in much of London is by permit or pay-and-display, so it helps to know what’s near you in Bromley Common. A visitor permit or a nearby bay makes the visit run more smoothly.
- First, we look at the surrounds with you and agree what needs doing.
- We rake out the old mastic and clean the joint.
- We pack any deep gaps so the mastic sits at the right depth.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
How to prepare
- Mention any sign-in or site rules at work premises
- Where the joints are inside, avoid wetting them before we arrive
- Mention any parking rules near the property
Getting a quote
Want a quote for sand mastic? Please ring 0345 464 0079 or email us and tell us about the job. You’ll know what we plan to do, and what it will cost, before any work begins.
Related advice
Common problems we fix in Bromley Common
Over the years, sand mastic weathers. It dries out, cracks and loses its grip on the stone or timber.
Signs it’s time to call us include:
- Failed mastic on an exposed elevation
- Draughty sash windows at the surround
- Gaps between timber frames and stone or brick
- Tired mastic found when preparing windows for paint
Managing a site like Trinity Church of England Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Questions to ask before you book
- Is the old sealant removed completely?
- Is VAT in the price?
- Are they insured?
- Whether you can choose the colour
How the job changes by surface
Period and listed homes
Many older homes were built with sand mastic round the windows. If your home is listed, ask your local planning authority about consent.
Tenement and terrace windows
Upper-floor windows need access planning. Tell us the height and we’ll confirm what’s needed.
What sealant work can’t fix
Honest advice matters more to us than a booking, so here’s what sealant cannot fix:
- Putty and glazing repairs
- Timber that has rotted
- Masonry that needs repairing
If in doubt, ring 0345 464 0079 or drop us an email and we will say what we think before booking.
What we seal
- Tenement windows
- Timber door frames
- Period & listed homes
- Stone surrounds
- Sash and case windows
- Brick reveals
DIY versus a professional finish
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.
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.
Landlord and commercial work in Bromley Common
Mouldy or split sealant often shows up at the end of a tenancy. Several properties can be quoted together.
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a one-year guarantee.
Places near Bromley Common
Other services in Bromley Common
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Ask the planning authority about consent for listed or conservation-area homes
- Ask a joiner to look at soft timber first
- Keep modern sealant off the mastic
- Ask us before painting near the mastic
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look rather than patching it.
Small cracks are a sign the mastic is ageing. It’s easier to renew it before it drops out.
What sand mastic looks like in Bromley Common
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. In a converted house or block, who looks after the windows depends on the lease, so it’s worth checking before booking.
Rented homes near Bickley station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about. Homes close to Holy Trinity Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Bromley Common is about 2 miles south-east of Bromley, in Greater London. Bromley Common 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, Bromley Common among them. London is on our list too, about 10 miles from Bromley Common.
We cover every part of BR2 and BR1 for sand mastic and the streets around it. That includes homes and businesses on Pope Road, Crown Lane and Church Lane and the roads around them. If you’re just outside Bromley Common, we cover Southborough (1 mile north-east), Hayes (1 mile south-west), Locksbottom (1 mile south-east), Shortlands (2 miles north-west) and Keston (2 miles south). We also work in nearby towns such as London (10 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (13 miles north-west), St Pancras (12 miles north-west) and Shoreditch (11 miles north-west).
What’s near Bromley Common
Typical jobs here are in homes near Norman Park, The Chequers Public House and Bishop Justus CofE School and the streets around them. For rail, the closest station is Bickley station, about 1.2 miles north of the centre. Other landmarks nearby include Bridgeways Day Hospital (within half a mile east) and Bethlem Museum of the Mind (under half a mile south-west). The countryside around Bromley Common includes Summer Hill and Downham Woodland Walk.