Greater London · England
External Mastic in Haverstock
Professional external mastic in and around Haverstock, with every bit of old sealant taken out first and a 12-month guarantee.
- Panel joints letting water in
- Sealant pulling away from one side of the joint
- Movement joints with cracked, split or missing sealant
External mastic for homes and businesses in Haverstock
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, so once it splits or hardens, the joint stops working and water gets in. We work on render & cladding joints, concrete & block and copings & trims, and the jobs we see most are brick movement joints where the sealant has split and sealant pulling away from one side of the joint.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Haverstock, tell us how high the joints are and how to reach the back of the building.
A 12-month guarantee comes with the work, just as it does everywhere we cover.
- Place
- Haverstock (NW3, NW5, NW1)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Haverstock questions
Do you work for landlords with property near South Hampstead station?
Yes, we work for landlords and agents. Just call 0345 464 0079 or drop us an email and tell us about the property, and we will give you a clear price.
Is parking a problem for a job in Haverstock?
Parking in Haverstock, as in most of London, takes a little planning: a visitor permit or a nearby bay makes the day run more smoothly.
Are you fully insured?
Yes. We’re fully insured, and we have been doing sealant work for more than 20 years.
Where is Mr Mastic based?
Our base is Crawley. Our area covers South East England, London and Scotland.
Can you do several jobs on one visit?
Yes. More than one area can be quoted together.
Is the work guaranteed?
Yes, always. Each job is guaranteed for twelve months.
Do you take out the old sealant first?
Yes, every time. New silicone does not stick to old silicone, so any old material comes out before anything new goes in.
What sealant do you use?
Each joint gets the product that suits it. Movement, water and weather all affect the choice.
DIY versus a professional 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 does not work out, we can still put it right.
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Different surfaces, different methods
Brickwork movement joints
People sometimes point up a brick movement joint by mistake. Where one has been mortared, we cut it out and reseal it with sealant if the joint can be cleared.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. We choose the product to suit.
Nearby places to Haverstock
More services for Haverstock
When something else is needed
It helps to know what we can’t do too:
- Damp that isn’t coming from the joint
- Subsidence or other structural problems
- Render that’s blown, hollow or coming away
If you’re not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer.
What we seal
- Façade panels
- Copings & trims
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
Common problems we fix in Haverstock
Many joints fail because they were sealed too deep or with nothing behind them. If the sealant sticks to the back as well as the sides, it can’t stretch and rips as the joint opens.
The problems people usually mention when they call include:
- Old sealant gone brittle and cracked
- Brick movement joints where the sealant has split
- Joints where the bead has come unstuck
- Plants rooting in failed movement joints
Haverstock is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What to look for in a quote
- The length of the guarantee
- Whether VAT is included
- Which colour the sealant will be
- Whether all the old sealant comes out first
Why deal with it now?
Sealing over the top of old mastic doesn’t hold for long. New sealant does not bond well to old, weathered sealant, 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. Putting it right early is much less trouble for homes in Haverstock.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. Your quote takes all of that into account.
What you get with us
- We are fully insured
- 20+ years of sealant experience
- Anti-fungal silicone where joints get wet
- 180+ five-star Google reviews
Take a look at our cost guide or our reviews.
Outside joints around Haverstock
In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Managing a site like Fine Arts College? Then larger buildings have long runs of movement joint that eventually need resealing. Letting a property close to South Hampstead station? Then outside joints that have cracked can let damp into a rental, so check them between lets.
Haverstock is about 1 mile south-east of Hampstead, in Greater London. From the centre of Haverstock to the outskirts, external mastic is available for homes and businesses alike. Haverstock is one of 764 towns and villages in Greater London where we work for external mastic.
We cover every part of NW3, NW5 and NW1 for external mastic. Streets in the area include Eton Road, Lawn Road and Ornan Road. Nearby, we also carry out external mastic in Belsize Park (1 mile north), Primrose Hill (1 mile south), South Hampstead (1 mile west), Swiss Cottage (1 mile west) and Chalk Farm (1 mile east). Larger places within reach include London (4 miles south-east), Kensington (4 miles south-west), Shoreditch (4 miles east), Walthamstow (7 miles north-east), Hoxton (3 miles east) and Whitechapel (4 miles south-east).
Landmarks near Haverstock
Locally, jobs take us to homes and businesses close to Cecil Sharp House, Primrose Hill and St. Mary's Town and Country School. Other local landmarks include St Paul's Church of England Primary School (within half a mile south) and The Washington pub (less than half a mile north). Haverstock’s nearest station is South Hampstead station, about 0.7 miles west of the centre. Nearby you will also find Wellington Hospital (0.9 miles south-west) and Isokon Gallery (0.5 miles north). Open spaces near Haverstock include Adelaide Nature Reserve and Primrose Hill.
How the visit works
A visit follows a simple pattern: we look at the joints together, mask and protect the surrounding surfaces, carry out the job and tidy away. Most jobs take anything from a few hours to several days, depending on the building. In a London area like Haverstock, the main things to plan are parking and access: tell us about permits, visitor bays or off-street space, which floor we’re working on and whether there’s a lift.
- 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.
Getting ready for the visit
- Mention any parking rules near the property
- Clear the area around the work
- Keep children and pets away from the work area
Get a quote
Call for a quick quote, or email us if that’s easier. Tell us about the joints that need doing and we will explain what’s involved.
Advice
Landlords, agents and businesses in Haverstock
We also work for property managers and facilities teams. Several sites can be quoted together.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.