Greater London · England
External Mastic in Upper Edmonton
External mastic for Upper Edmonton, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Damp patches traced to an open external joint
- Sealant that has lost its bond to the brick or render
- Hard, crazed mastic that has stopped moving
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Clear growth from the base of walls and joints
- Act on the first splits you see
- Point out the joints to other trades
- Ask before painting over external sealant
Keep pressure washers away from the sealant. A strong jet can damage the edges of the bead over time.
Once a joint cannot move, the wall finds another way, often as cracks near the joint. Resealing it early helps prevent that.
How we handle external mastic in Upper Edmonton
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible exterior sealant takes up that movement where a rigid filler would soon crack. Common call-outs are for joints with sealant missing in places and weeds or debris growing in open joints, on joints between brick and frames, render & cladding joints and brickwork movement joints.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Period houses have different weak points, such as gutter joints, trims and the line where an extension meets the old wall.
The work is covered for a year after we finish. If anything is not right with it, ring 0345 464 0079 or send us an email.
- Place
- Upper Edmonton (N18, N9, N17)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Also near Upper Edmonton
More services for Upper Edmonton
Landlord and commercial work in Upper Edmonton
We also work for property managers and facilities teams in Upper Edmonton and across Greater London. Several sites can go on one quote, and we’re fully insured.
For anyone letting property in or around Upper Edmonton, several properties can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
How it works
On the day, we start by going over the job with you, so there are no surprises. Surfaces next to the work are protected before work begins. Most jobs take anything from a few hours to several days, depending on the building. For a job in Upper Edmonton, 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 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.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- Mention any tricky access
- Let us know about earlier repairs to the joints
- Move anything stored near the joints
Ask for a quote
To get a quote, ring 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You’ll have a clear quote before any work starts.
Read more
Do you need external mastic in Upper Edmonton?
If plants are growing out of a joint, the sealant has usually failed or was never there. Dirt and roots then trap moisture in the joint and make things worse.
Look out for these signs:
- Damp patches traced to an open external joint
- Hard, crazed mastic that has stopped moving
- Joints pointed up with cement by mistake
- Sealant that has lost its bond to the brick or render
If you live in an older home near St Mary's Church, the joints between older walls, newer extensions and the roofline need a sealant that can move.
What your quote should include
- Whether they’re fully insured
- Is the old sealant removed completely?
- How the surfaces are prepared before sealing
- Whether the sealant suits the joint
Walls and rooflines in Upper Edmonton
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Upper Edmonton is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. Schools such as St John and St James CofE Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Upper Edmonton is about 1 mile south of Edmonton, in Greater London. Whether you’re in the middle of Upper Edmonton or further out, external mastic is available for homes and businesses alike. Across Greater London, we cover 764 places, Upper Edmonton among them. London is on our list too, about 8 miles from Upper Edmonton.
Here we cover the N18, N9 and N17 postcode area for external mastic. Local streets include Bull Lane, Park Lane and York Road. If you are just outside Upper Edmonton, we cover Northumberland Park (1 mile south-east), Edmonton (1 mile north), Picketts Lock (2 miles north-east), South Chingford (2 miles east) and Winchmore Hill (2 miles north-west). Within a short drive, we also cover London (8 miles south), City of Westminster (8 miles south-west), Marylebone (8 miles south-west), Kensington (10 miles south-west), St Pancras (6 miles south) and Shoreditch (6 miles south).
Local landmarks in Upper Edmonton
Typical jobs here are in homes near Pymmes Park, Tottenham University Technical College and London Academy of Excellence Tottenham. There’s a railway station in Upper Edmonton itself: Silver Street station. Other landmarks nearby include North Middlesex University Hospital (under half a mile west) and Broomfield House Museum (2.2 miles west). Not far away are Pole Hill and Highams Park Lake.
DIY sealant or a professional job?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.
Some sealant jobs are within reach of a careful DIYer, 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.
How the job changes by surface
Copings and trims
Copings expand and contract through the day, so the joints need a sealant that stays flexible year round.
Brickwork movement joints
Brick movement joints are often mistaken for a missing mortar line. If that’s happened, we rake it out and reseal it properly.
Common questions in Upper Edmonton
Do you cover Upper Edmonton for external mastic?
Yes, Upper Edmonton 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.
Is parking an issue for external mastic in Upper Edmonton?
In much of London, parking needs planning: a visitor permit or a nearby bay makes the day run more smoothly, so mention what’s available when you book.
Are you ARBOMaster approved?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Do I have to be there?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
What information do you need?
Where the job is, what the problem is and roughly how big it is. Photos by email help too.
Can you seal joints between two different materials?
Yes. Materials like render, brick, metal and uPVC all move differently, so the joint between them must be flexible. We choose one that suits both surfaces.
Can you do several jobs on one visit?
Yes, we can. More than one area can go on one quote.
How do you reach high-level joints?
It depends on the height and the site. Low-level joints are straightforward; for higher work, tell us about the building and we’ll confirm what’s needed.
When it isn’t the sealant
We will always be straight with you, so here’s what sealant cannot fix:
- Cracking across the wall rather than at a joint
- Failed render or damaged cladding panels
- Rising or penetrating damp from elsewhere in the wall
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before you book.
Surfaces we seal
- Façade panels
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
- Render & cladding joints
- Copings & trims