Greater London · England
External Mastic in Widmore
External mastic across Widmore and nearby, with old sealant always removed completely and a one-year guarantee.
- Joints pointed up with cement by mistake
- Cracked joints where brick meets render or frames
- Failed sealant between panels on a façade
External mastic in Widmore
We are ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Some surfaces need a primer before sealing, and we don’t skip that step. Typical jobs include sealant pulling away from one side of the joint and weathered mastic that no longer stretches, across joints between brick and frames, render & cladding joints and façade panels.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Widmore, tell us how high the joints are and how to reach the back of the building.
Whatever the size of the job, you get the same 12-month guarantee.
- Location
- Widmore (BR1, BR2, BR7)
- Region
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- 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 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 for homes in Widmore.
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please ring 0345 464 0079 or drop us an email.
Why Widmore clients choose us
- Anti-fungal sanitary silicone in wet areas
- Full insurance on every job
- Every job guaranteed for a year
- 20+ years of sealant experience
Also in Widmore
Looking after it afterwards
A little care helps the new joints last. We recommend:
- Never let anyone fill a movement joint with mortar
- Ask before painting over external sealant
- Keep high-pressure jets off the joints
- Point out the joints to other trades
Follow the cure time we give you before the joint is knocked or disturbed. Most exterior sealants skin fast but take longer to cure right through.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years.
When something else is needed
Sealant isn’t the answer to every problem, and we will tell you before work begins. It won’t solve:
- Walls that need new movement joints cut into them
- Movement that is more than a sealant joint can take
- Failed render or damaged cladding panels
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
Joints and surfaces we work on
- Copings & trims
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Concrete & block
- Brickwork movement joints
How it works
There is not much for you to do on the day. Show us the job and we’ll take it from there. The work itself takes a few hours for a handful of joints, longer for a whole elevation from start to finish. Many London jobs are in flats, so we come ready for stairs, narrow hallways and shared entrances. If the building has a concierge, managing agent or access rules, tell us when you book.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Let us know about parking restrictions
- Let us know about earlier repairs to the joints
Getting a quote
For a quote, phone 0345 464 0079 or email us and tell us where the job is and what the problem looks like. We’ll send you a clear quote before any work starts.
Related advice
Can I do it myself?
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it peels away and traps moisture behind it. All the old material has to come out first.
Work for landlords, hotels and businesses
Hotels need rooms back in use, so the work can be planned room by room. We’ve worked in hotels as well as homes and businesses.
Landlords and agents in Widmore can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
When to call us in Widmore
A lot of failed joints come down to preparation: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
These are the problems we’re asked about most:
- Brick movement joints where the sealant has split
- Rigid filler in a joint that should flex
- Plants rooting in failed movement joints
- Failed seals between different materials
If you live in an older home near Church of St George, older walls, gutters and the joints where extensions meet them need a flexible sealant.
What your quote should include
- How the surfaces are prepared before sealing
- Whether VAT is included
- Whether they’re fully insured
- Whether they seal over old material or remove it
Widmore buildings and the weather
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. With historic houses such as Bromley Palace (about 1.1 miles west) nearby, there’s older building stock in the area around Widmore as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
Letting a property close to Bickley station? Then failed wall and movement joints let damp in, so they’re worth checking between tenancies. If you look after a building such as Bullers Wood School for Boys, larger buildings have long runs of movement joint that eventually need resealing.
Widmore is about 1 mile east of Bromley, in Greater London. Homes, rented property, offices and hotels in Widmore is covered for external mastic. The work is guaranteed for a year. Our Greater London coverage runs to 764 places, Widmore among them. We also work in London, around 9 miles away.
We work across the BR1, BR2 and BR7 postcode area for external mastic and the streets around it. Whether your property is on Golf Road, The Avenue and Canon Road or anywhere close by, our applicators can take on the job. Close by, we work in Bickley (1 mile north), Elmstead (1 mile north), Chislehurst (1 mile north-east), Bromley (1 mile west) and Sundridge (1 mile north-west). Within a short drive, we also cover London (9 miles north-west), City of Westminster (12 miles north-west), Marylebone (12 miles north-west), Kensington (13 miles north-west), St Pancras (11 miles north-west) and Shoreditch (10 miles north-west).
Around Widmore
Locally, jobs take us to homes and businesses close to Bird In Hand Public House, St George's and Jubilee Country Park. Widmore has its own railway station: Bickley station. Nearby you will also find Bridgeways Day Hospital (1 mile south) and The Mall (1.3 miles west). For a walk, there’s Summer Hill and The Tarn.
Questions from Widmore
Can you do external mastic in Widmore?
Yes, Widmore is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or email us and let us know what needs doing.
Can you help a landlord with a rental near Bickley station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, so we never do it.
What colours does the sealant come in?
Exterior sealants are made in a range of colours, from greys and browns to whites and stone shades. We pick the one that suits your wall best so it doesn’t stand out.
Should I try DIY first?
Some simple jobs can be done by a careful DIYer. Most DIY failures come from sealing over old material, wet joints or too much sealant.
Is there a guarantee?
Yes, always. There’s a 12-month guarantee on every job.
What does external mastic cost?
We do not publish prices, because the cost depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
How long does external mastic take?
Typically it takes a few hours for a handful of joints, longer for a whole elevation. Larger jobs naturally take longer.