Greater London · England
Sand mastic for sash & case windows in Bermondsey, Greater London
Problem with your window and door surrounds in Bermondsey? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Cracked mastic round a front door frame
- Mastic worn away on windows facing the weather
- Open joints round the window box
How we handle sand mastic in Bermondsey
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. We work on stone surrounds, timber door frames and sash and case windows, and people most often call us about mastic dropping out of the joint and tired mastic found when preparing windows for paint.
London has a lot of flats and conversions, where windows are often on upper floors. In a converted house or block, the lease usually says who is responsible for the windows, so it’s worth checking before booking, and access in Bermondsey is something to talk through when you book.
You’re covered for a year from the day we finish. If anything is not right with it, call 0345 464 0079 or send us an email.
- Place
- Bermondsey (SE1, SE16, SE5)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
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.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Different surfaces, different methods
Brick reveals
Gaps between frame and brick let in rain and draughts. Renewing the mastic closes it.
Tenement and terrace windows
Upper-floor windows need access planning. Let us know the floor and we’ll confirm access.
Do you need sand mastic in Bermondsey?
Some old mastic was never deep enough. Mastic that’s too thin cracks and drops out so we make sure the new mastic is the right thickness.
If you can see any of these, it’s time to have the joints looked at:
- Gaps round a timber door in stone or brick
- Mastic that needs renewing before redecorating
- Gaps where the frame meets the masonry
- Old cement repairs round a window that have failed
Managing a site like Boutcher Church of England Primary School? Then its window and door frames need their mastic kept sound, just like a home’s.
What to look for in a quote
- How long the guarantee is
- Who turns up on the day
- What product goes in the joint
- When the joint can take water or movement
DIY sealant or a professional job?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
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.
Common questions in Bermondsey
Can you do sand mastic in Bermondsey?
Yes, Bermondsey is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we’ll give you a clear price.
Do you work for landlords with property near London Bridge station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. You can ring 0345 464 0079 or send us an email with the details for a clear quote.
How long does sand mastic take to harden?
It takes a while. The skin forms first, and the full set comes later, and we will tell you what to expect.
Can I paint the new mastic?
Traditional guidance is not to paint over sand mastic. Ask us before you decorate around it and we’ll talk you through it.
Do you have insurance?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
What does sand mastic cost?
We don’t publish prices, because the cost depends on the job: its size, the old material, access and the product needed. You will get a clear quote before work begins.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What information do you need?
A short description and the location, plus pictures if you have them. If we need more, we’ll ask.
What happens on the day
Our applicators work methodically: protect, prepare, seal, tidy. For most jobs that takes anything from a few hours to a full day, depending on how many windows and we leave things clean and tidy. In a London area like Bermondsey, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Mention any leaks or damp you’ve noticed
- Tell us about access, such as stairs, a lift or high-level joints
- For business premises, tell us about site rules or sign-in
Ask for a quote
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To get started, ring 0345 464 0079 or send us an email.
Related advice
Aftercare tips
To keep the joints looking good and working properly:
- Ask the planning authority about consent for listed or conservation-area homes
- Ask a joiner to look at soft timber first
- Plan mastic work ahead of painting
- Avoid heavy scraping on the mastic joint
Make sure water drains away from the window surround. Constant wetting wears the mastic faster.
Renewing mastic before redecorating saves doing it twice. Paint over cracked mastic only covers it up.
Places near Bermondsey
More services for Bermondsey
Frames and glazing around Bermondsey
Historic houses like Mansion House (about 1.3 miles north-west) are a reminder that the area around Bermondsey has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Homes close to St Mary Magdalen Bermondsey include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. As a London address, Bermondsey can be tricky for parking: tell us about permits, visitor bays or off-street space when you book.
Bermondsey is about 1 mile east of London, in Greater London. From the centre of Bermondsey to the outskirts, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Our Greater London coverage runs to 764 places, and Bermondsey is one of them.
Postcode districts we cover here for sand mastic: SE1, SE16 and SE5. Whether your property is on Crown Square, Fire Station Square and Layard Square or anywhere close by, we can help. Main roads around Bermondsey include the A100 and B202, which makes travel easy. We also cover the places around Bermondsey: Walworth (1 mile south-west), London (1 mile west), South Bermondsey (1 mile south-east), Surrey Canal (1 mile south-east) and Surrey Quays (1 mile east). We also work in nearby towns such as City of Westminster (4 miles west), Marylebone (3 miles north-west), Kensington (5 miles west), St Pancras (3 miles north-west), Walthamstow (7 miles north) and Hoxton (3 miles north).
Landmarks near Bermondsey
Around Bermondsey, our work takes us to homes and buildings near Asylum for the deaf and dumb, St Mary-at-Hill and Harris Academy Bermondsey and the streets around them. Other local landmarks include Bishopsgate Institute Special Collections and Archives (1.5 miles north), Bermondsey Spa Gardens (under half a mile south) and Simon the Tanner pub (within half a mile west). For rail, the closest station is London Bridge station, about 0.7 miles north-west. Well-known places in the area include Fashion and Textile Museum (within half a mile west) and Guy's Hospital (0.7 miles north-west). Open spaces near Bermondsey include St. James's Park Lake and Bellenden Road Nature Garden.
Leave it or put it right?
Replacing sash windows is a big decision for a period home, and in listed buildings it may need consent. If the frames are sound, renewing the mastic deals with gaps and draughts at the surround. In London conversions, one flat’s bathroom is often above another flat’s ceiling, so a small leak from tired sealant can mean a neighbour’s ceiling and a lot of disruption. Dealing with it early is far simpler.
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we’ll go through it with you.
What you get with us
- We never seal over old sealant
- Every job guaranteed for a year
- 4.9 on Google from 180+ five-star reviews
- Arbo and Everbuild products
Read our cost guide or our reviews.