Greater London · England
External Mastic in Arkley
We cover Arkley for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly.
- Rigid filler in a joint that should flex
- Hard, crazed mastic that has stopped moving
- Moss and dirt in joints with no sealant left
External mastic for homes and businesses in Arkley
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, leaving it bonded to two faces so it can move with the wall. We are often asked to deal with joints where the bead has come unstuck and weathered mastic that no longer stretches, on joints between brick and frames, render & cladding joints and copings & trims.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so a leaking gutter joint or failed wall joint can affect more than one home. In a converted house in Arkley, it’s worth checking who is responsible for the outside before booking.
You are covered for a year from the day we finish. If there’s a problem with it, please ring 0345 464 0079 or send us an email.
- Where
- Arkley (EN5, NW7)
- Region
- Greater London
- Guarantee
- A year, on every job
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
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 matched to the joint and its conditions.
When to call us in Arkley
UV, rain and frost all age exterior sealant. Over the years it hardens, cracks on the surface and loses its give, so the next time the wall moves, it splits or pulls away.
Common reasons people contact us include:
- Gaps where render, brick and frames meet
- Rigid filler in a joint that should flex
- Sealant that has lost its bond to the brick or render
- Weeds or debris growing in open joints
Arkley is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Questions to ask before you book
- Is VAT in the price?
- Whether you can choose the colour
- When the joint can take water or movement
- How much experience the applicator has
What sealant work cannot fix
New sealant cannot fix everything, and we will tell you before any work starts. Sealant won’t put right:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Movement that’s more than a sealant joint can take
- Loose or hollow render, which needs re-rendering
If in doubt, call 0345 464 0079 or drop us an email and we will say what we think.
What we seal
- Render & cladding joints
- Façade panels
- Joints between brick and frames
- Copings & trims
- Brickwork movement joints
- Concrete & block
Leave it or put it right?
Low-modulus sealants stretch easily, so they put less strain on the joint edges. That protects surfaces like brick, render and concrete. Too stiff a sealant can pull at the edges and break them. In older London homes, water behind a failed joint soaks into brick and timber without much sign, and by the time it shows on a wall or ceiling in Arkley, the repair is bigger than the sealant job would have been.
The cost reflects the work involved, not a rough estimate. That is why we ask a few questions first.
Why book with us
- More than 20 years in sealant work
- Domestic, commercial and hotel work
- Anti-fungal silicone where joints get wet
- Arbo and Everbuild products
Questions from Arkley
Do you cover Arkley for external mastic?
Yes. Our work covers London and the South East, and Arkley is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
Do you work for landlords with property near Elstree & Borehamwood station?
Yes. We work for landlords and letting agents as well as homeowners. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear quote.
When will the joints need doing again?
It varies from wall to wall: joints on exposed walls or with a lot of movement age sooner. Check them each year and reseal when they split or harden. Every job carries our one-year guarantee.
Do you seal joints where cladding meets other materials?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. The colour is chosen to suit.
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 will confirm what’s needed.
Are you fully insured?
Yes. We’re fully insured, with over 20 years’ experience in sealant work.
What should I tell you?
Tell us what needs doing and where. If we need more, we’ll ask.
Can you work on commercial sites?
Yes. We work in offices, washrooms, hotels and other commercial premises, as well as homes. We can talk about working times when we quote.
Nearby places to Arkley
Other services in Arkley
Landlords, agents and businesses in Arkley
From a single let to a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
We also work for property managers and facilities teams in Arkley and across Greater London. Several sites can go on one quote, and we’re fully insured.
Outside joints around Arkley
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Wyllyotts Manor (about 3.7 miles north-east) are a reminder that the area around Arkley has older buildings as well as new. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
For site and facilities teams at buildings such as Whitings Hill Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. Rented homes near Elstree & Borehamwood station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Arkley is about 2 miles west of Barnet, in Greater London. Arkley gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Arkley is one of 764 towns and villages in Greater London where we work for external mastic. You can also see our page for London, roughly 12 miles from Arkley.
Every address in EN5 and NW7 is within our area for external mastic. Whether your property is on Well Road, Glebe Lane and Brett Road or anywhere close by, we can help. Arkley sits on or near the A411, so getting to you is simple. Nearby, we also carry out external mastic in Rowley Green (1 mile north-west), High Barnet (1 mile north-east), Hadley (1 mile north-east), Totteridge (2 miles south-east) and Well End (2 miles north-west). We also work in nearby towns such as London (12 miles south-east), City of Westminster (10 miles south), Marylebone (10 miles south), Kensington (10 miles south), St Pancras (10 miles south-east) and Shoreditch (11 miles south-east).
What’s near Arkley
Locally, jobs take us to homes and businesses close to Susi Earnshaw Theatre School, Whitings Hill Open Space and Queen Elizabeth's School and the streets around them. Arkley’s nearest station is Elstree & Borehamwood station, roughly 2.1 miles west. Other landmarks nearby include Hilfield Castle (4.5 miles west) and Hertfordshire Scout Museum (1.9 miles north-west). Not far away are Glebe Lane Pastures and Darland's Lake.
The process
We keep the work tidy and contained to the joints we are treating, so you can get on with your day. Expect the work to take anything from a few hours to several days, depending on the building, and we tell you how long to leave it before we go. In Arkley, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- 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 tricky access
- Tell us about any previous sealing or DIY attempts
- Mention any sign-in or site rules at work premises
Ask for a quote
If you are in Arkley and need external mastic, call 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before work begins.
Related advice
How the job changes by surface
Copings and trims
A failed coping joint lets water into the top of the wall. Resealing them is a small job that protects a lot.
Render joints
Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.