Greater London · England
External Mastic in Roehampton
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Roehampton and across Greater London. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Weeds or debris growing in open joints
- Sealant pulling away from one side of the joint
- Weathered mastic that no longer stretches
External mastic in Roehampton, done properly
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. We pick a colour that sits well with the wall so the joint does not stand out. We work on façade panels, brickwork movement joints and joints between brick and frames, and people most often call us about brick movement joints where the sealant has split and moss and dirt in joints with no sealant left.
Modern London flats rely on sealed movement joints and cladding joints. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall.
A 12-month guarantee comes as standard, so you’re covered after we have gone.
- Location
- Roehampton (SW15, SW13)
- Region
- Greater London
- Cover
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
Roehampton buildings and the weather
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Fulham Palace (about 1.3 miles north-east) nearby, there’s older building stock in the area around Roehampton as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
For an older house near a landmark such as St Margaret's Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. As a London address, Roehampton can be tricky for parking: let us know about parking bays, permits or a driveway.
Roehampton is about 2 miles south-west of Fulham, in Greater London. Homes, rented property, offices and hotels in Roehampton is covered for external mastic. Every job comes with our 12-month guarantee. 764 places in Greater London are on our list. There’s also a page for London, about 7 miles away.
Jobs for external mastic in SW15 and SW13 works the same way as everywhere else we cover. Whether your property is on Rodway Road, Cortis Road and Torwood Road or a nearby road, we can help. Close by, we work in Putney (1 mile north-east), Barnes (1 mile north), Mortlake (1 mile north-west), East Sheen (1 mile north-west) and Putney Vale (2 miles south-west). We also work in nearby towns such as London (7 miles north-east), City of Westminster (5 miles north-east), Marylebone (6 miles north-east), Kensington (3 miles north-east), St Pancras (7 miles north-east) and Shoreditch (8 miles north-east).
Local landmarks in Roehampton
We work in homes and buildings around King's Head pub, The Falcons School for Girls and ARK Putney Academy. The nearest railway station is Barnes station, roughly 0.8 miles north. A little further out are Queen Mary's Hospital (less than half a mile west) and Putney Exchange (1 mile north-east). The countryside around Roehampton includes Kew Gardens Lake and Duke's Hollow.
How the visit works
We keep the work tidy and contained to the joints we are treating, so you can carry on as normal. The job normally takes anything from a few hours to several days, depending on the building. In a London area like Roehampton, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we are working on and whether there’s a lift.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- We cut out the failed sealant and rake out any dirt or growth.
- We clean both faces of the joint and prime them where the product calls for it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Before we arrive
- On commercial sites, let us know about site rules
- Clear items away from the joints we are working on
- Try not to wet indoor joints just before the visit
Get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that’s easy.
Advice
DIY sealant or a professional job?
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is.
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.
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Leave it or put it right?
The longer a joint stays open, the more water the wall takes in. Wet masonry is more easily damaged by frost around the joint, so the problem grows beyond the joint itself. In a flat in Roehampton, 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.
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you’re unsure, ring 0345 464 0079 or send us an email for an honest opinion and a quote.
Why book with us
- Old sealant always removed completely
- 180+ five-star Google reviews
- Full insurance on every job
- Colour agreed with you before we start
Honest limits
A few problems are outside what sealant work can do:
- Movement that’s more than a sealant joint can take
- Walls that need new movement joints cut into them
- Loose or hollow render, which needs re-rendering
If in doubt, ring 0345 464 0079 or email us and we’ll say what we think.
What we seal
- Brickwork movement joints
- Joints between brick and frames
- Copings & trims
- Render & cladding joints
- Concrete & block
- Façade panels
Roehampton: your questions answered
I let a flat near Barnes station. Can you help?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will send you a clear quote.
Can parking be tricky for a visit in Roehampton?
In much of London, parking needs planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Do you remove the old sealant?
Yes. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
How do I get a quote for external mastic in Roehampton?
It depends on the job, so we quote each one individually. For a quick quote, phone 0345 464 0079 or send us an email and tell us what needs doing and where.
How long does external mastic take?
That depends on the amount of work, but most jobs take a few hours to a few days, depending on the length of joint and the access. We’ll give you a better idea when we quote.
Which products do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Do I have to be there?
That depends on where the joints are. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
Why is there a gap in my brick wall?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It’s sealed with a flexible sealant, not mortar.
Different surfaces, different methods
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod in a colour to suit the brick.
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one.
Do you need external mastic in Roehampton?
Poor preparation causes many early failures: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
Signs it’s time to call us include:
- Rigid filler in a joint that should flex
- Weeds or debris growing in open joints
- Failed seals between different materials
- Old sealant gone brittle and cracked
If you look after a building such as Granard Primary School, larger buildings have long runs of movement joint that eventually need resealing.
What to look for in a quote
- Are they insured?
- Whether you can choose the colour
- What product goes in the joint
- What guarantee comes with the work
How to look after the new joints
A little care helps the new joints last. Our advice:
- Show decorators and builders where the movement joints are
- Wash walls gently around the sealant
- Keep movement joints as flexible joints, not mortar
- Look over the joints every year, ideally after winter
Follow the cure time we give you before the joint is knocked or disturbed. The surface skins over quickly, but full cure takes longer.
Small splits are the time to act. Then it’s a straightforward cut-out and reseal.