Greater London · England
Window Mastic in Bermondsey
Specialist window mastic for Bermondsey: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Cracked or shrunken mastic around the frame
- Rushed sealant from a window installation
- Old mastic that has gone black or come away
How we handle window mastic in Bermondsey
A cold draught around a closed window often comes from the frame edge. A new joint stops the air getting through. Where the air is getting in through the window itself, we’ll say so. We work on window sills, composite doors and aluminium frames, and common reasons people get in touch are mastic that’s falling out in pieces and cracked sealant at the sill ends.
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.
All our work comes with our one-year guarantee.
- Place
- Bermondsey (SE1, SE16, SE5)
- Region
- Greater London
- Cover
- A year, on every job
- Quotes
- A clear price before we start
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Windows and doors in 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 timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so it’s worth checking before booking.
Managing a site like Boutcher Church of England Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages. Bermondsey is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Bermondsey is about 1 mile east of London, in Greater London. Anywhere in SE1, we cover window mastic for homes and businesses. Our area takes in 764 places across Greater London.
Postcode districts we cover here for window mastic: SE1, SE16 and SE5. You will find streets such as Crown Square, Fire Station Square and Layard Square, all of which we cover. Main roads around Bermondsey include the A100 and B202, so getting to you is simple. We also cover 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).
What’s near Bermondsey
Locally, jobs take us to homes and businesses close to Asylum for the deaf and dumb, St Mary-at-Hill and Harris Academy Bermondsey, among other places. Also close by are Bishopsgate Institute Special Collections and Archives (1.5 miles north), Bermondsey Spa Gardens (less than half a mile south) and Simon the Tanner pub (less than half a mile west). Bermondsey’s nearest station is London Bridge station, about 0.7 miles north-west of the centre. Nearby you will also find Fashion and Textile Museum (under half a mile west) and Guy's Hospital (0.7 miles north-west). For a walk, there’s St. James's Park Lake and Bellenden Road Nature Garden.
Leave it or put it right?
Redecorating is a good moment to renew the mastic. A clean new bead makes new paint or render look finished. In a flat in Bermondsey, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
A failed joint rarely gets cheaper to fix by waiting. If you are not sure whether it needs doing, call 0345 464 0079 or email us and we will give you an honest view and a quote.
What you get with us
- Rated 4.9 stars on Google
- More than 20 years in sealant work
- Full insurance on every job
- A choice of colours where the product allows
Read what affects the cost or our reviews.
What we do, step by step
There’s no need to move everything out before we come, just the space around the work. We protect the rest, and the work takes a morning for a couple of windows and a door in most cases. In Bermondsey, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- We check each frame and agree which ones need doing.
- Next the failed sealant is cut away and the joint cleaned.
- Where gaps are deep, backing rod goes in first.
- New exterior sealant goes on in a matching colour and is tooled smooth.
- Every joint is checked before we leave.
Preparing for the visit
- On commercial sites, let us know about site rules
- Let us know about parking restrictions
- Let us know about earlier repairs to the joints
How to get a quote
If you are in Bermondsey and need window mastic, ring 0345 464 0079 or send us an email. Tell us what the problem is and where, and you’ll get a clear quote before work begins.
Advice
Also near Bermondsey
What else we do in Bermondsey
Bermondsey: your questions answered
Is parking an issue for window mastic in Bermondsey?
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.
Do you cover Bermondsey for window mastic?
Yes. Our work covers London and the South East, and Bermondsey is part of that. You can call 0345 464 0079 or send us an email and tell us what needs doing.
Can you seal over the old sealant?
No. Fresh sealant does not stick to old sealant, and anything trapped underneath, including mould and water, stays there. It all has to come out first.
Is the new sealant paintable?
That depends on the product. Some hybrid sealants can be painted; silicone cannot. Tell us if you are decorating and we’ll choose accordingly.
Can I do it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. The usual mistakes are sealing over old sealant, sealing a damp joint and using too much.
Do you seal inside as well as outside?
Yes. Plenty of draughts come through the inside joint as well as the outside, so sealing both is often worthwhile.
Do you guarantee window mastic?
Yes. Our 12-month guarantee covers every job, inside or out.
How long should I leave it?
It depends on the product and the conditions. We tell you how long to leave it before we go.
Aftercare tips
Simple care keeps the joints in good condition. We recommend:
- Keep timber frames painted
- Wipe condensation off the frames
- Look round the frames every year or so
- Keep jet washers away from the mastic
Wipe the frames with soapy water when you clean the windows, and keep solvents and harsh chemicals off the joint.
Leaks generally show up in wet, windy weather, but resealing works best in dry conditions. Dealing with it when you first notice a crack avoids chasing leaks through the wet months.
Landlord and commercial work in Bermondsey
Failed sealant is one of the commonest items on a check-out report, and it’s easy to sort out between tenants. Several properties can go on one quote.
If you manage several properties in or around Bermondsey, several properties can go on one quote. Send us the addresses and the work at each.
Should I try it myself first?
If you’ve already had a go yourself, that is fine. We remove it and do the joint properly, so tell us about it when you ask for a quote.
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.
When to call us in Bermondsey
Joints that are too thin or too deep fail early. A skim of sealant over a wide gap soon tears, while a joint packed solid cannot stretch. Backing rod sets the right depth.
These are the problems we’re asked about most:
- Leaking joints at the ends of sills
- Cracked internal joints between frame and plaster
- Mastic that’s falling out in pieces
- Draughts coming in around windows and doors
If you live in an older home near St Mary Magdalen Bermondsey, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What your quote should include
- What the quote includes, VAT included or not
- How long the guarantee is
- How the colour is chosen
- Which sealant they’ll use, and why
How the job changes by surface
uPVC windows
Plastic frames move a lot between a hot afternoon and a cold night, so we use a flexible, low-modulus sealant. White is the usual colour, with brown, anthracite grey and black for coloured frames.
Patio & French doors
Water at the foot of a door frame isn’t always the mastic: worn seals, blocked drainage slots or a poor threshold detail can be the cause. We look for the cause first.