Greater London · England
Bentley Heath External Mastic
Specialist external mastic for Bentley Heath: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Damp patches traced to an open external joint
- Movement joints with cracked, split or missing sealant
- Rigid filler in a joint that should flex
External mastic for homes and businesses in Bentley Heath
We’re ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Some surfaces need a primer before sealing. If you’re dealing with cracked joints where brick meets render or frames and leaking joints around cladding and façade panels, we can help.
In London terraces and converted houses, gutters and walls are often shared with the house next door, so one failed joint can cause damp for more than one household. For a flat in Bentley Heath, check the lease for who looks after the outside.
Big or small, it’s backed by our one-year guarantee.
- Location
- Bentley Heath (EN5)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Quote
- A clear price before work begins
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Questions from Bentley Heath
Do you cover Bentley Heath for external mastic?
Yes, Bentley Heath is within the area we cover. Our work covers London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job.
Can you help a landlord with a rental near Potters Bar station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear quote.
Is there any odour?
There can be a smell while the sealant cures, but it fades. Opening a window helps.
What should I tell you?
Tell us what needs doing and where, with pictures by email if possible. If we need more, we will ask.
Do you remove the old sealant?
Yes, every time. New sealant won’t bond properly to old, so the joint is cleaned back first.
Can you do several jobs on one visit?
Of course. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Can you seal joints between render and window frames?
Yes. Different materials move at different rates, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We explain the product when we quote.
Also near Bentley Heath
Also in Bentley Heath
Bentley Heath buildings and the weather
Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts.
If you look after a building such as Pope Paul Catholic Primary School, larger buildings have long runs of movement joint that eventually need resealing. Bentley Heath is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book. For landlords with property near Potters Bar station, split movement joints are easy to miss on a rental until damp shows inside.
Bentley Heath is about 1 mile south-west of Potters Bar, in Greater London. Homes, rented property, offices and hotels in Bentley Heath can book us for external mastic. The work is guaranteed for a year. Our area takes in 764 places across Greater London, from the larger towns to small villages. London is on our list too, about 13 miles from Bentley Heath.
Postcode districts we cover here for external mastic: EN5. We also cover the places around Bentley Heath: Potters Bar (1 mile north-east), Monken Hadley (1 mile south), Hadley Wood (2 miles south-east), Underhill (3 miles south) and Northaw Valley (3 miles east). Larger places within reach include London (13 miles south), City of Westminster (12 miles south), Marylebone (12 miles south), Kensington (13 miles south), St Pancras (11 miles south) and Shoreditch (12 miles south-east).
Landmarks near Bentley Heath
Around Bentley Heath, our work takes us to homes and buildings near King George's Fields (Monken Hadley), Dame Alice Owen's School and Duke of York pub, among other places. The closest station to Bentley Heath is Potters Bar station, roughly 1 mile north of the centre. Well-known places in the area include Barnet General Hospital (2.4 miles south) and Potters Bar Museum (0.9 miles north). Green spaces nearby include Furzefield Wood and Lower Halfpenny and Darland's Lake.
What we cannot put right
New sealant cannot fix everything, and we will tell you before we start. Sealant will not put right:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracks in the bricks or render themselves, away from the joints
- Movement that is more than a sealant joint can take
Not sure which it is? You can call 0345 464 0079 or drop us an email and we’ll tell you honestly before you book.
Surfaces we seal
- Façade panels
- Joints between brick and frames
- Concrete & block
- Brickwork movement joints
- Render & cladding joints
- Copings & trims
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Avoid pressure-washing directly into sealant joints
- Show decorators and builders where the movement joints are
- Don’t let climbing plants root in the sealant
- Walk round the building once a year and look at the joints
Make sure anyone working on the wall later knows where the movement joints are. They must stay as flexible joints, never rendered or pointed over.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
For landlords and businesses
Whether it’s one flat or a portfolio, you get the same standard of work: old sealant fully removed, joints prepared properly and a 12-month guarantee.
We work for landlords and agents as well as householders. Sealant work between tenants keeps a property looking cared for.
Leave it or put it right?
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That matters on brick, render and concrete, which can be weaker at the face. Too stiff a sealant can pull at the edges and break them. In a flat in Bentley Heath, failed sealant seldom stays inside your own four walls: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
Every job is a little different, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference.
Why Bentley Heath clients choose us
- ARBOMaster approved applicator
- Colour picked to suit the job
- Rated 4.9 stars on Google
- We leave the area clean and tidy
Take a look at how sealant jobs are priced and customer reviews.
What the job involves on each surface
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. We reseal them with a low-modulus sealant over backing rod coloured to suit the wall.
Copings and trims
A failed coping joint lets water into the top of the wall. Sealing them early saves the wall below.
DIY sealant or a professional job?
The biggest DIY mistake is sealing over old sealant. New silicone will not bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
If you are 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.
How the visit works
We keep the work tidy and contained to the area we are working on. Expect the work to take a few hours for a handful of joints, longer for a whole elevation, and we explain the cure time before we leave. In Bentley Heath, flats, stairs and shared entrances are part of the routine. If the building has a concierge, managing agent or access rules, tell us when you book.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- We clean both faces of the joint and prime them where the product calls for it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Plan for the work area to be out of bounds to pets and children
- Let us know about parking restrictions
Ask for a quote
Every job is quoted individually, so start by telling us what you need. Just phone 0345 464 0079 or send us an email with the details and send pictures if you have them.