Greater London · England
Dancers Hill External Mastic
Our applicators work in Dancers Hill on sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly and every job guaranteed for a year.
- Cracked joints where brick meets render or frames
- Joints with sealant missing in places
- Damp patches traced to an open external joint
Signs you need external mastic in Dancers Hill
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 cannot stretch and tears as soon as the joint widens.
Common reasons people contact us are:
- Sealant that has lost its bond to the brick or render
- Brick movement joints where the sealant has split
- Hard, crazed mastic that has stopped moving
- Joints pointed up with cement by mistake
If you look after a building such as Dame Alice Owen's School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What to look for in a quote
- What guarantee comes with the work
- How the joint is cleaned and prepared
- What happens if the job turns out different
- Which sealant they’ll use, and why
External mastic for homes and businesses in Dancers Hill
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we will confirm what access is needed. If you have joints pointed up with cement by mistake and weeds or debris growing in open joints, we can put it right.
Outside work in London starts with access: side passages, upper floors and where to park. For a home in Dancers 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, phone 0345 464 0079 or drop us an email.
- Location
- Dancers Hill (EN5)
- Region
- Greater London
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Should I try it myself first?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
What the job involves on each surface
Cladding and façade panels
Panels heat up and cool down quickly, so the joints work hard every day. We choose the product to suit.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. Their movement joints are sealed over backing rod with a flexible sealant.
Nearby places to Dancers Hill
What else we do in Dancers Hill
The process
The work is kept neat and contained to the area we are working on. Expect the work to take a few hours to a few days, depending on the length of joint and the access, and we tell you how long to leave it before we go. In a London area like Dancers Hill, 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 start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- 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.
Preparing for the visit
- Let us know if you’ve seen damp or leaks
- Mention if the joints have been sealed before
- Where the joints are inside, avoid wetting them before we arrive
Getting a quote
Getting a quote is simple: let us know the job and the location, and roughly how big it is. A few photos by email make the job easier to understand.
Advice
Aftercare tips
No joint lasts for ever, but care makes a real difference. Our tips:
- Point out the joints to other trades
- Keep movement joints as flexible joints, not mortar
- Get split or bare joints resealed while the damage is small
- Check external joints each spring
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
For landlords and businesses
We work for landlords and agents as well as homeowners. Resealing between tenancies keeps a property looking cared for before the next move-in.
We also work for property managers and facilities teams in Dancers Hill and across Greater London. We can quote a run of properties together, and we’re fully insured.
What affects the cost of external mastic
There’s no set price list, because no two jobs are the same. The quote depends on:
- The amount of work
- Whether the work is at height
- Which sealant suits the joint
- How much old sealant there is and how hard it is to remove
A failed joint rarely gets cheaper to fix by waiting, as water and mould keep getting in. 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.
Helping us quote
What to tell us when you ask for a quote:
- How we’d reach the joints
- The address or postcode of the job
- How many joints, rooms or windows are involved
- The problem you’ve noticed
If you’re in Dancers Hill and need external mastic, phone 0345 464 0079 or email us. A short description of the job and where it is helps us quote, and we will agree the price before any work begins.
What external mastic looks like in Dancers Hill
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
As a London address, Dancers Hill can be tricky for parking: tell us about permits, visitor bays or off-street space when you book. Wyllyotts Manor, about 1.5 miles north-east, is one of the historic houses in the wider area around Dancers Hill, and older homes nearby need a sealant that suits their walls.
Dancers Hill is about 2 miles south-west of Potters Bar, in Greater London. For external mastic in and around Dancers Hill, it’s easy to get a quote: please phone 0345 464 0079 or drop us an email. We’re based in Crawley and cover Greater London, Dancers Hill included. Dancers Hill is one of 764 places in Greater London where we work. For nearby work, see our London page.
Here we cover the EN5 postcode area for external mastic. We also cover the places around Dancers Hill: Kitts End (1 mile south-east), South Mimms (1 mile north-west), Ridge (1 mile north-west), High Barnet (2 miles south) and Hadley (2 miles south). Larger places within reach include London (14 miles south), City of Westminster (12 miles south), Marylebone (12 miles south), Kensington (12 miles south), St Pancras (11 miles south) and Shoreditch (12 miles south-east).
Near you in Dancers Hill
Around Dancers Hill, our work takes us to homes and buildings near King George's Fields (Monken Hadley), Pope Paul Catholic Primary School and The Green Dragon Public House and the streets around them. The nearest railway station is Potters Bar station, about 1.5 miles north-east of the centre. Nearby you will also find Barnet General Hospital (2.1 miles south) and Spires Shopping Centre (1.8 miles south). Not far away are Darland's Lake and Hadley Green.
Dancers Hill questions
Is parking an issue for external mastic in Dancers Hill?
Parking in Dancers Hill, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot.
Can you do external mastic in Dancers Hill?
Yes. We work across London and the South East, and Dancers Hill is part of that. Just call 0345 464 0079 or email us with a few details of the job.
Do you hold any approvals?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
How do you reach high-level joints?
It depends on the building. We work on joints that can be reached safely. Tell us about the building and we’ll confirm what access is needed.
What colours does the sealant come in?
We aim for a joint that suits the wall rather than one that jumps out. Colour is agreed with you before we begin from the range available.
What should I tell you?
The location, the problem and the rough size of the job. If you can, email a few photos.
Do you remove the old sealant?
Yes. We cut out all the old sealant and clean the joint before resealing.
Do you seal joints where cladding meets other materials?
Yes. Different materials move at different rates, so the joint between them must be flexible. We choose one that suits both surfaces.