Greater London · England
External Mastic in Foxbury
External mastic for Foxbury and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Moss and dirt in joints with no sealant left
- Brick movement joints where the sealant has split
- Gaps where render, brick and frames meet
How we handle external mastic in Foxbury
A movement joint is only as good as its depth. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. Typical jobs include joints where the bead has come unstuck and damp patches traced to an open external joint, on joints between brick and frames, copings & trims and concrete & block.
Modern London flats rely on sealed movement joints and cladding joints. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Place
- Foxbury (DA14, BR7, DA15)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
What happens if it’s left?
Running new sealant over the old bead rarely lasts. The new layer can’t bond properly to old, weathered material, so the old joint is cut out fully first. In a flat in Foxbury, 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.
Doing several joints on one visit is usually more efficient than separate visits, so tell us about everything that needs sealing. We’ll send you a clear quote for the lot.
Why book with us
- Approved under the ARBOMaster scheme
- We agree the colour with you first
- Colour picked to suit the job
- White, clear, grey or coloured to suit, where the product allows
How the job changes by surface
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joint sealant has to cope with frequent movement. We choose the product to suit.
Render joints
Rendered walls have joints at beads, openings and changes of material. They’re resealed in a sealant that suits the render.
Towns and villages near Foxbury
More services for Foxbury
Should I try it myself first?
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
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 doesn’t work out, we can still put it right.
How it works
There is not much for you to do on the day. Point us to the joints and we’ll get on with it. The work itself takes a few hours to a few days, depending on the length of joint and the access. For a job in Foxbury, parking and access are the things to plan: let us know about parking, the floor we’ll be working on and any lift or shared entrance.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Try not to wet indoor joints just before the visit
- Mention any tricky access
- Mention any sign-in or site rules at work premises
Getting a quote
For a quote, phone 0345 464 0079 or send us an email with the location and a short description of the problem. You’ll have a clear quote before we start.
Advice
What external mastic looks like in Foxbury
Historic houses like Eltham Palace (about 2.6 miles north-west) are a reminder that the area around Foxbury has older buildings as well as new. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
As a London address, Foxbury can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Managing a site like Chislehurst School for Girls? Then larger buildings have long runs of movement joint that eventually need resealing. For an older house near a landmark such as Christ Church, an extension built onto an older house moves differently, and the joint between them takes the strain.
Foxbury is about 1 mile east of Chislehurst, in Greater London. Anywhere in DA14, we can carry out external mastic at your property. Our Greater London coverage runs to 764 places, Foxbury among them. London is on our list too, around 10 miles away.
We work across DA14, BR7 and DA15 for external mastic. You will find streets such as Kemnal Road, Sydney Road and Carlton Road, all of which we cover. If you’re just outside Foxbury, we cover Longlands (1 mile north), Chislehurst (1 mile west), New Eltham (1 mile north-west), Elmstead (2 miles west) and Coldharbour (2 miles north-west). Within a short drive, we also cover London (10 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (14 miles north-west), St Pancras (12 miles north-west) and Shoreditch (10 miles north-west).
What’s near Foxbury
We work in homes and buildings around Chislehurst Common, Mead Road Infant School and The Bulls Head Public House, among other places. The nearest railway station is Sidcup station, about 1.2 miles north-east of the centre. Other landmarks nearby include The Glades (3.3 miles west) and Queen Mary's Hospital (0.6 miles east). For a walk, there’s Summer Hill and The Tarn.
Foxbury questions
Do you work for landlords with property near Sidcup station?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. Just phone 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Can you do external mastic in Foxbury?
Yes, Foxbury is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job, and we’ll send you a clear quote.
Is it OK to fill a movement joint with cement?
No, not if it’s a movement joint. Pointing it stops it working. We’ll reseal it with a flexible sealant.
Is the work guaranteed?
Yes, for a year. If anything is not right with the work within the year, let us know and we will sort it.
What should I tell you?
A short description and the location. We will ask anything else we need to know.
Do you seal joints where cladding meets other materials?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
Do you take out the old sealant first?
Yes, always, and completely. New silicone does not stick to old silicone, so the joint is cleaned back first.
Can you reach joints on upper floors?
It depends on the building. Tell us the height, the number of joints and what’s below them, and we will confirm what access is needed.
What we cannot put right
We’d rather tell you now than do work that will not last, so these are the limits:
- Movement that’s more than a sealant joint can take
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Render that is blown, hollow or coming away
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly before booking.
Joints and surfaces we work on
- Render & cladding joints
- Concrete & block
- Façade panels
- Joints between brick and frames
- Copings & trims
- Brickwork movement joints
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Check the sealant is paintable before painting near it
- Never let anyone fill a movement joint with mortar
- Don’t let climbing plants root in the sealant
- Point out the joints to other trades
Keep the joints clear of soil, plants and climbing growth. Anything that holds water against the joint wears it out sooner.
Small splits are the time to act. At that stage it’s a simple cut out and reseal before water has had years to get in.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.