Greater London · England
Gospel Oak External Mastic
Movement joints in Gospel Oak need attention? We remove the old material, prepare the joints and seal them properly, and the work is guaranteed for a year.
- Movement joints with cracked, split or missing sealant
- Hard, crazed mastic that has stopped moving
- Failed sealant between panels on a façade
External mastic for homes and businesses in Gospel Oak
Ground-floor and low-level joints are straightforward to reach. Where joints are higher up, tell us about the building when you get in touch and we will confirm what’s needed to reach them safely. If you have sealant that has lost its bond to the brick or render and weeds or debris growing in open joints, we can put it right, whatever the surface.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. In Gospel Oak, joints up high may need ladders or other access, which is worth talking through when you book.
A one-year guarantee comes as standard, so you are not left on your own once the job is done.
- Where
- Gospel Oak (NW5, NW3, NW1)
- Wider area
- Greater London
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
How the visit works
Once we’re on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. Most jobs then take a few hours to a few days, depending on the length of joint and the access. In a London area like Gospel Oak, the main things to plan are parking and access: 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.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Let us know if you’ve seen damp or leaks
- Try not to wet indoor joints just before the visit
- Mention any parking rules near the property
Get a quote
Call for a quick quote, or send an email if you’d rather. Describe what needs sealing and we’ll explain what’s involved.
Related advice
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Gospel Oak: your questions answered
Can you help a landlord with a rental near Gospel Oak station?
Yes. We work for landlords and letting agents as well as householders. 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.
Is parking a problem for a job in Gospel Oak?
London parking needs a little planning, so let us know about permits, bays or a driveway when you book. The visit is then planned around what’s available.
How long does external mastic last?
That varies with the weather the wall faces, how much it moves and the sealant used. Treat it as a maintenance item and look at it yearly and renew it when it starts to fail.
Can you quote for more than one area?
Yes. Tell us about everything you’d like done and you will get one quote.
What’s an expansion joint in brickwork?
A vertical gap in a long brick wall is usually a movement joint. It lets the bricks expand without cracking and needs a flexible seal, not mortar.
How long should I leave it?
Cure times vary by product. Before we leave, we’ll tell you the cure time.
Will the new joint stand out?
We choose a sealant colour to suit the brick, stone or render. There’s a wide choice of exterior colours.
Do you use backing rod?
Backing rod controls the sealant depth and keeps it off the back of the joint. That way it bonds to the two sides only and can stretch.
Landlords, agents and businesses in Gospel Oak
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance that we can handle for you.
If you manage several properties in or around Gospel Oak, several properties can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
DIY versus a professional finish
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.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
What the job involves on each surface
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Cladding and façade panels
If the façade has a specified sealant, that is what we use, or one the system allows. Send us any details you have about the façade.
When to call us in Gospel Oak
Using the wrong sealant is another common reason. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
If you can see any of these, it’s time to have the joints looked at:
- Leaking joints around cladding and façade panels
- Hard, crazed mastic that has stopped moving
- Moss and dirt in joints with no sealant left
- Movement joints with cracked, split or missing sealant
For site and facilities teams at buildings such as Carlton Primary School, its movement joints, gutters and trims need looking after like any other building’s.
What to look for in a quote
- Whether you can choose the colour
- Whether the sealant suits the joint
- Whether they’re fully insured
- What the quote includes, VAT included or not
When something else is needed
Some problems need a builder, plumber or other trade rather than us:
- Rising or penetrating damp from elsewhere in the wall
- Cutting new joints into brickwork, which is building work rather than sealant work
- Movement that’s more than a sealant joint can take
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
What we seal
- Brickwork movement joints
- Joints between brick and frames
- Concrete & block
- Render & cladding joints
- Copings & trims
- Façade panels
Why deal with it now?
A failed movement joint lets water into the wall. Resealing early keeps the job to the joint itself, instead of the wall and finishes around it. Converted houses in London often have a bathroom above someone else’s living room, 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 Gospel Oak.
Leaving a failed joint normally makes the job bigger, not smaller. If you’re not sure whether it needs doing, phone 0345 464 0079 or send us an email for an honest opinion and a quote.
What you get with us
- Quality sealants from Arbo and Everbuild
- Neat joints and a tidy finish
- Colour agreed with you before we start
- Every job guaranteed for a year
See our cost guide and what customers say.
Outside joints around Gospel Oak
With historic houses such as Keats House (about 0.9 miles west) nearby, there’s older building stock in the area around Gospel Oak as well as newer homes. In older buildings, 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.
If you live in an older home near Highgate Road Chapel, the joints between older walls, newer extensions and the roofline need a sealant that can move. For landlords with property near Gospel Oak station, outside joints that have cracked can let damp into a rental, so check them between lets.
Gospel Oak is about 1 mile east of Hampstead, in Greater London. If you need external mastic in Gospel Oak, it’s easy to get a quote: please ring 0345 464 0079 or drop us an email. We cover Greater London from our Crawley base. Gospel Oak is one of 764 towns and villages in Greater London we cover.
We work across the NW5, NW3 and NW1 postcode area for external mastic and the streets around it. Whether your property is on Rona Road, Dale Road and Regis Road or anywhere close by, we can help. We also cover the places around Gospel Oak: Lissenden Gardens (1 mile north), Dartmouth Park (1 mile north-east), Kentish Town (1 mile south), Tufnell Park (1 mile east) and Chalk Farm (1 mile south). We also work in nearby towns such as London (4 miles south-east), City of Westminster (3 miles south), Kensington (4 miles south-west), Shoreditch (4 miles south-east), Walthamstow (6 miles north-east) and Hoxton (3 miles south-east).
Near you in Gospel Oak
Around Gospel Oak, our work takes us to homes and buildings near Vaughan Williams Memorial Library, St. Mary's Town and Country School and Bull and Gate pub and the streets around them. Nearby too are Parliament Hill (0.7 miles north-west) and Parliament Hill School (less than half a mile north). Gospel Oak has its own railway station: Gospel Oak station. Well-known places in the area include Royal Northern Hospital (1.2 miles north-east) and O2 Centre (1.5 miles west). Green spaces nearby include Belsize Wood and The Long Water.