Greater London · England
Forty Hill External Mastic
Problem with your movement joints in Forty Hill? We cut out the old, prepare the joints and apply the right sealant.
- Weathered mastic that no longer stretches
- Movement joints filled with mortar instead of sealant
- Leaking joints around cladding and façade panels
Aftercare tips
So the new joints stay in good condition:
- Get split or bare joints resealed while the damage is small
- Never let anyone fill a movement joint with mortar
- Keep high-pressure jets off the joints
- Check external joints each spring
Keep pressure washers away from the sealant. A strong jet can damage the edges of the bead.
Act while the splits are small. At that stage it’s a simple cut out and reseal with no damage behind it to deal with.
External mastic for homes and businesses in Forty Hill
External mastic is a job where short cuts show quickly. New sealant over old, joints packed with mortar and beads with no backing all tend to fail early. We take the old material out and do it properly. Common call-outs are for water getting into walls through failed joints and sealant pulling away from one side of the joint, on copings & trims, façade panels and render & cladding joints.
Working on the outside of a London home means planning access: shared paths, upper floors and parking. For a home in Forty Hill, tell us how high the joints are and how to reach the back of the building.
You are covered for a year from the day we finish. If anything is not right with it, ring 0345 464 0079 or drop us an email.
- Location
- Forty Hill (EN1, EN2)
- Region
- Greater London
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Nearby places to Forty Hill
What else we do in Forty Hill
Why deal with it now?
Mortar or ordinary filler might look like a quick way to close an open joint, but it stops the joint moving. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. 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 Forty Hill.
What it costs depends on the amount of work, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before any work starts.
Why choose Mr Mastic in Forty Hill
- 4.9 on Google from 180+ five-star reviews
- An ARBOMaster approved applicator
- Old sealant always removed completely
- 12-month guarantee on every job
Read what affects the cost and what customers say.
Landlords, agents and businesses in Forty Hill
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance that we can handle for you.
We regularly work with letting and managing agents. Tell us the address, the job and how access works and we will quote.
The process
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours for a handful of joints, longer for a whole elevation and we leave things clean and tidy. For a job in Forty Hill, parking and access are the things to plan: tell us about permits, visitor bays or off-street space, which floor we are 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.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- For business premises, tell us about site rules or sign-in
- Let us know about parking restrictions
- Keep pets and children clear of the area while we work
Get a quote
We do not publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or email us.
Read more
External mastic in Forty Hill: local notes
With historic houses such as Forty Hall (about 0.3 miles north) nearby, there’s older building stock in the area around Forty Hill as well as newer homes. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth. In terraces and conversions, gutters and walls are often shared with the neighbours, so check who is responsible for the outside before booking.
In the older streets around Jesus Church, the joints between older walls, newer extensions and the roofline need a sealant that can move. If you let a flat or house near Turkey Street station, outside joints that have cracked can let damp into a rental, so check them between lets.
Forty Hill is about 1 mile north-east of Enfield, in Greater London. Our applicators cover external mastic for homeowners, landlords and businesses in Forty Hill and the surrounding area, as part of our work across Greater London. Across Greater London, we cover 764 places, and Forty Hill is one of them. For nearby work, see our London page (12 miles or so).
We cover every part of the EN1 and EN2 postcode area for external mastic and the streets around it. Streets in the area include Goat Lane, Acacia Road and Willow Road, all of which we cover. We also cover the places around Forty Hill: Gordon Hill (1 mile west), Clay Hill (1 mile north-west), Bulls Cross (1 mile north), Enfield (1 mile south-west) and Bullsmoor (1 mile north-east). Further out, we also cover London (12 miles south), City of Westminster (11 miles south), Marylebone (11 miles south), Kensington (13 miles south-west), St Pancras (10 miles south) and Shoreditch (10 miles south).
Around Forty Hill
Typical jobs here are in homes near Chace Community School, Hop Poles pub and Russet House School. Forty Hill’s nearest station is Turkey Street station, about 1 mile north-east of the centre. Other landmarks nearby include Edmonton Green Shopping Centre (2.9 miles south) and Museum of Enfield (1.2 miles south-west). Green spaces nearby include Fir and Pond Woods and Pole Hill.
Forty Hill questions
I let a flat near Turkey Street station. Can you help?
Yes, we work for landlords and agents. You can ring 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before work begins.
Is Forty Hill in your area for external mastic?
Yes, Forty Hill is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
Do you do commercial work?
Yes. Larger jobs can be planned room by room or area by area to suit the site.
Do you seal joints where cladding meets other materials?
Yes. We cut out the old sealant, prepare both faces and reseal with a flexible exterior product. We pick a colour that works with both materials.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator, and we are fully insured.
Can you do several jobs on one visit?
Yes. Several rooms, windows or areas can go on one quote.
Do you take out the old sealant first?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It sets the sealant depth and prevents three-sided bonding so the bead can stretch.
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
What we’re called out for in Forty Hill
Sometimes a movement joint was filled with mortar or a rigid filler, often by someone who didn’t know what it was for. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
People usually contact us when they notice one of these:
- Damp patches traced to an open external joint
- Failed sealant between panels on a façade
- Failed seals between different materials
- Hard, crazed mastic that has stopped moving
Forty Hill is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
What your quote should include
- How long to leave it before use
- Whether they seal over old material or remove it
- What guarantee comes with the work
- How the joint is cleaned and prepared
Honest limits
We’d rather tell you now than do work that will not last, so here’s what sealant cannot put right:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Movement that’s more than a sealant joint can take
- 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.
Joints and surfaces we work on
- Brickwork movement joints
- Façade panels
- Concrete & block
- Joints between brick and frames
- Copings & trims
- Render & cladding joints