Greater London · England
External Mastic in Eastcote
Problem with your movement joints in Eastcote? We cut out the old, prepare the joints and apply the right sealant.
- Hard, crazed mastic that has stopped moving
- Sealant pulling away from one side of the joint
- Joints with sealant missing in places
Do you need external mastic in Eastcote?
A lot of failed joints come down to preparation: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The new sealant then lets go long before it should.
If you can see any of these, it’s time to have the joints looked at:
- Failed sealant between panels on a façade
- Hard, crazed mastic that has stopped moving
- Damp patches traced to an open external joint
- Sealant that has lost its bond to the brick or render
If you let a flat or house near Headstone Lane station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Before you book anyone
- Who turns up on the day
- The length of the guarantee
- Are they insured?
- When the joint can take water or movement
How we handle external mastic in Eastcote
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. We work on joints between brick and frames, façade panels and render & cladding joints, and people most often call us about leaking joints around cladding and façade panels and movement joints with cracked, split or missing sealant.
London’s terraces and conversions often share walls, gutters and downpipes with their neighbours, so one failed joint can cause damp for more than one household. In a converted house in Eastcote, it’s worth checking who is responsible for the outside before booking.
All our work is covered by a 12-month guarantee.
- Location
- Eastcote (HA5, HA4, HA2)
- Wider area
- Greater London
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
What affects the cost of external mastic
We don’t publish a price list. The quote depends on:
- Mould in or behind the old joints
- Which sealant suits the joint
- How much old sealant there is and how hard it is to remove
- When we can work, for business premises
We don’t show prices on the website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or drop us an email.
Asking for a quote
To help us quote quickly, let us know:
- Where the property is
- The problem you’ve noticed
- Whether it’s a home or a business
- Roughly how big the job is
There’s no standard price list. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or drop us an email.
For landlords and businesses
Housing providers, facilities teams and property managers book us too. We can quote a run of properties together.
Letting agents often deal with us directly. Tell us the address, the job and how access works and we will give you a quote.
Towns and villages near Eastcote
Other services in Eastcote
When it is not the sealant
We will always be straight with you, so here’s what new sealant will not do:
- Cracks in the bricks or render themselves, away from the joints
- Adding movement joints to masonry that has none
- Failed render or damaged cladding panels
If in doubt, ring 0345 464 0079 or send us an email and we will say what we think before you book.
What we seal
- Joints between brick and frames
- Brickwork movement joints
- Render & cladding joints
- Copings & trims
- Concrete & block
- Façade panels
How the job changes by surface
Concrete and blockwork
Concrete faces can be dusty and porous, so preparation is key. A primer goes on where the product requires one.
Copings and trims
Coping and trim joints face rain and sun head on. Each is resealed with a weatherproof, flexible sealant.
Your questions about external mastic in Eastcote
I let a flat near Headstone Lane station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before work begins.
Can you do external mastic in Eastcote?
Yes, Eastcote is within the area we cover. Our work covers London and the South East. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
Will the old sealant be removed?
Yes, always, and completely. New silicone doesn’t stick to old silicone, so any old material comes out before anything new goes in.
When will the joints need doing again?
It varies with how exposed the wall is and how much the joint moves. Look for splits, hardening or edges coming away.
Are you an approved applicator?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We’ll tell you what we’re using and why.
Do you do commercial work?
Yes. We can plan bigger jobs in stages.
How long does external mastic take?
A typical job takes a few hours for a handful of joints, longer for a whole elevation. Your quote will say how long we expect yours to take.
External mastic in Eastcote: local notes
London terraces and converted houses often share gutters, downpipes and walls, so it’s worth agreeing who is responsible before work starts. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
In the older streets around St Lawrence, the joints between older walls, newer extensions and the roofline need a sealant that can move. Eastcote is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Eastcote is about 1 mile north-east of Ruislip, in Greater London. Across the HA5 area, we can carry out external mastic at your property. Our area takes in 764 places across Greater London, large and small. For nearby work, see our London page.
Postcode districts we cover here for external mastic: HA5, HA4 and HA2. That includes homes and businesses on Hill Road, Bridle Road and Cannon Lane and the roads around them. Nearby, we also carry out external mastic in Pinner (1 mile north), Roxbourne (1 mile south-east), Pinner Green (1 mile north), Rayners Lane (1 mile south-east) and North Harrow (1 mile east). Larger places within reach include London (14 miles south-east), City of Westminster (11 miles south-east), Marylebone (11 miles south-east), Kensington (10 miles south-east), St Pancras (12 miles east) and Shoreditch (14 miles east).
What’s near Eastcote
We work in homes and buildings around Pinner High School, The Whittington pub and Heathfield School, among other places. The nearest railway station is Headstone Lane station, roughly 1.9 miles north-east. Well-known places in the area include Northwood and Pinner Cottage Hospital (1.7 miles north-west) and St. George's Shopping Centre (2.2 miles east). Not far away are Horse Shoe Bay and Islip Manor Meadows.
What happens if it’s left?
Running new sealant over the old bead rarely lasts. New sealant does not bond well to old, weathered sealant, so we always take the old sealant out. In a London flat, a failed joint rarely stays your problem alone: water from a shower or window joint can reach the flat below, and gaps in fire-stopping matter to everyone in the building.
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in Eastcote
- Trusted Arbo and Everbuild sealants
- Neat joints and a tidy finish
- Approved under the ARBOMaster scheme
- 20+ years of sealant experience
Take a look at what affects the cost and customer reviews.
How the visit works
When we get to you, we compare the joints with what we discussed. If we find something unexpected, we talk it through with you first. Most jobs then take anything from a few hours to several days, depending on the building. In a London area like Eastcote, the main things to plan are parking and access: let us know about parking, the floor we will be working on and any lift or shared entrance.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- Primer is applied wherever the sealant needs it.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- For business premises, tell us about site rules or sign-in
- Mention if the joints have been sealed before
- Try not to wet indoor joints just before the visit
Ask for a quote
Call for a quick quote, or email us if that is easier. Tell us about the joints that need doing and we’ll talk you through the work.