Greater London · England
Sand mastic for sash & case windows in Bromley, Greater London
Specialist sand mastic for Bromley: careful preparation, the right product and tidy work. Call for a quick quote.
- Draughts and rain around sash boxes
- Tired mastic found when preparing windows for paint
- Weathered mastic on the most exposed windows
About our sand mastic in Bromley
For a listed home or one in a conservation area, ask your local planning authority whether consent is needed for work to windows. Sand mastic is often favoured as a like-for-like material. We work on period & listed homes, timber door frames and stone surrounds, and common reasons people get in touch are tired mastic found when preparing windows for paint and mastic round period door frames that has failed.
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 Bromley as anywhere.
Each job carries a 12-month guarantee, large or small.
- Where
- Bromley (E3, E14, E15)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
How the visit works
Most of a good job is in the preparation, and we don’t rush it. Joints are cleaned back and dried before anything new goes in. All told, the work takes anything from a few hours to a full day, depending on how many windows. In Bromley, 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 the surrounds with you and agree what needs doing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- 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.
Getting ready for the visit
- Mention if the joints have been sealed before
- For business premises, tell us about site rules or sign-in
- Mention any leaks or damp you’ve noticed
Get a quote
For a quick quote, get us on the phone, or email us if that is easier. Describe what needs sealing and we will explain what’s involved and send you a clear quote.
Related advice
Honest limits
To be straight with you, there are a few things sealant will not fix:
- Timber that has rotted
- Decisions on consent for listed homes
- Sashes that rattle, stick or will not open
If in doubt, phone 0345 464 0079 or drop us an email and we’ll say what we think.
Surfaces we seal
- Brick reveals
- Tenement windows
- Period & listed homes
- Sash and case windows
- Stone surrounds
- Timber door frames
When to call us in Bromley
Decorating can disturb tired mastic. It’s often found when windows are being prepared for paint.
The most common problems we see are:
- Gaps where the frame meets the masonry
- Mastic round period door frames that has failed
- Old cement repairs round a window that have failed
- Old sand mastic that has cracked, crumbled or fallen out
Schools such as St Agnes RC Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
What to look for in a quote
- What the cure time is
- What preparation is included
- Who does the work, and how experienced they are
- Is VAT in the price?
What sand mastic looks like in Bromley
Historic houses like Sutton House (about 2.2 miles north-west) are a reminder that the area around Bromley has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Bromley is in London, so parking needs planning: let us know about parking bays, permits or a driveway. Homes close to Bow Church include some older properties, and the joint between an old wall and a newer frame is usually the first place rain gets in.
Bromley is about 2 miles east of Whitechapel, in Greater London. Our applicators cover sand mastic for homes and businesses in Bromley, as part of our work across Greater London. 764 places in Greater London are on our list.
Here we cover the E3, E14 and E15 postcode area for sand mastic. Whether your property is on Bow Road, Bruce Road and Edgar Road or anywhere close by, we can help. We also cover the places around Bromley: Three Mills (1 mile north-east), Mill Meads (1 mile north-east), Bow Common (1 mile south-west), Mile End (1 mile west) and Bow (1 mile north-west). Within a short drive, we also cover London (4 miles south-west), City of Westminster (6 miles west), Marylebone (6 miles west), Kensington (8 miles west), St Pancras (4 miles west) and Shoreditch (3 miles west).
Local landmarks in Bromley
Locally, jobs take us to homes and businesses close to Bob's Park, East London Arts & Music and Bow School. For rail, the closest station is West Ham station, roughly 1 mile east. Other landmarks nearby include Tower of London (2.8 miles south-west) and Stratford Centre (1.4 miles north-east). For a walk, there’s Old Ford Island and Tower Hill.
Why it’s worth doing now in Bromley
An open joint round the frame lets weather in. Water can get to the frame and the masonry, so dealing with it now protects both. In a flat in Bromley, 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.
What you pay reflects the work, not a rough estimate. That’s why we ask a few questions first.
Why choose Mr Mastic in Bromley
- Neat joints and a tidy finish
- Experience in homes, commercial sites and hotels
- Over 20 years’ experience
- Trusted Arbo and Everbuild sealants
Take a look at how sealant jobs are priced or what customers say.
FAQs for Bromley
Is parking a problem for a job in Bromley?
It can be, so it helps to tell us about permits, visitor bays or off-street space when you book. That way the visit can be planned around it.
Do you cover Bromley for sand mastic?
Yes, Bromley is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and let us know what needs doing, and we’ll send you a clear quote.
How do I get a quote for sand mastic in Bromley?
Every job is different, so each one gets its own quote. For a quick quote, ring 0345 464 0079 or send us an email and let us know what needs doing and where.
When will the new mastic be hard?
The surface skins quite quickly and it hardens fully over a longer time. Timing depends on the weather and the joint.
Is it possible to take out silicone and use sand mastic instead?
Generally, yes. With the silicone removed and the joint cleaned, sand mastic is applied by hand.
Will there be a smell?
There can be a smell while the sealant cures, which fades as it sets. Opening a window helps.
Is it messy?
No. The area is protected while we work and cleaned up afterwards.
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.
Towns and villages near Bromley
What else we do in Bromley
Should I try it myself first?
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
What the job involves on each surface
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. Sand mastic seals the joint round it.
Period and listed homes
Materials matter on listed and conservation-area homes. Like-for-like sand mastic is usually favoured.
What affects the cost of sand mastic
You will get a clear quote before work begins. It’s based on:
- The number and length of the joints
- When we can work, for business premises
- Any mould that needs treating
- How many areas need sealing
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.
Asking for a quote
When you contact us, it’s useful to know:
- Access, such as stairs, a lift or height
- Whether it has been sealed before
- If it’s domestic, commercial or a hotel
- A few photos by email, if you can
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and email photos if that is easy.