Greater London · England
External Mastic in Hatch End
Professional external mastic in and around Hatch End, with every bit of old sealant taken out first and a 12-month guarantee.
- Joints with sealant missing in places
- Moss and dirt in joints with no sealant left
- Water getting into walls through failed joints
External mastic in Hatch End, done properly
We cut out failed sealant, set the joint depth with closed-cell backing rod and reseal with a low-modulus exterior sealant. We pick a colour that sits well with the wall. We work on brickwork movement joints, copings & trims and concrete & block, and the jobs we see most are damp patches traced to an open external joint and cracked joints where brick meets render or frames.
Newer London blocks are built with movement joints in brick and render, and with cladding joints sealed with mastic. Older terraces have their own weak points: gutter joints, roofline trims and the joint where an extension meets the original wall.
You’re covered for a year from the day we finish. If anything isn’t right with it, call 0345 464 0079 or drop us an email.
- Place
- Hatch End (HA5, HA2, HA3)
- Region
- Greater London
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Landlords, agents and businesses in Hatch End
Hotels need rooms back in use, so the work can be planned room by room around your bookings where we can. Hotel work is part of what we do, alongside homes and businesses.
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.
How the visit works
We keep the work tidy and contained to the joints we’re treating. Expect the work to take a few hours to a few days, depending on the length of joint and the access. In Hatch End, flats, stairs and shared entrances are part of the routine. Mention any building rules, key holders or managing agents when you book.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- 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.
How to prepare
- Mention any leaks or damp you’ve noticed
- Try not to wet indoor joints just before the visit
- Move anything stored near the joints
Getting a quote
To get a quote, phone 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. You’ll have a clear quote before work begins.
Related advice
Common problems we fix in Hatch End
The wrong product in a moving joint is a classic cause. A stiff, general-purpose sealant cannot cope with a joint that moves a lot, so it pulls away from the edges.
Signs it’s time to call us include:
- Movement joints with cracked, split or missing sealant
- Sealant that has lost its bond to the brick or render
- Weathered mastic that no longer stretches
- Failed seals between different materials
Hatch End is in London, so parking needs planning: tell us about permits, visitor bays or off-street space when you book.
Comparing quotes
- What the cure time is
- Whether all the old sealant comes out first
- How hidden problems are handled
- Which colour the sealant will be
What the job involves on each surface
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one.
Render joints
The face of render can be soft, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
Outside joints around Hatch End
London terraces and converted houses often share gutters, downpipes and walls, so check who is responsible for the outside before booking. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Managing a site like Pinner Park Primary School? Then its movement joints, gutters and trims need looking after like any other building’s. Rented homes near Hatch End station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Hatch End is about 4 miles south of Watford, in Greater London. From the centre of Hatch End to the outskirts, external mastic is available for homes and businesses alike, from flats and houses to offices and hotels. Our Greater London coverage runs to 764 places, Hatch End among them. Our London page covers work nearby (14 miles or so).
All of HA5, HA2 and HA3 is within our area for external mastic. External mastic is available to properties on Love Lane, Moss Lane and Tudor Road and the roads around them. We also cover the places around Hatch End: Headstone (1 mile east), South Oxhey (2 miles north-west), Harrow Weald (2 miles east), Carpenders Park (2 miles north) and Belmont (2 miles east). Within a short drive, we also cover 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 south-east) and Shoreditch (14 miles east).
Local landmarks in Hatch End
Typical jobs here are in homes near The Moon & Sixpence pub, Nower Hill High School and Headstone Manor Recreation Ground and the streets around them. Hatch End’s nearest station is Hatch End station, roughly 0.6 miles north of the centre. Nearby you’ll also find Heath Robinson Museum (0.8 miles south-west) and Hilfield Castle (4 miles north-east). Green spaces nearby include Harrow Weald Common and Northala Fields.
Questions from Hatch End
Is parking a problem for a job in Hatch End?
Parking in Hatch End, as in most of London, takes a little planning: a visitor permit or a bay close to the door helps a lot, so mention what’s available when you book.
Can you help a landlord with a rental near Hatch End station?
Yes, we work for letting agents and landlords. Just ring 0345 464 0079 or send us an email and tell us about the property, and we will give you a clear price.
What does external mastic cost?
There’s no set price, as it depends on the job: how much there is, what’s there now, how we reach it and what it needs. You’ll get a clear quote before we start.
How long before the joint can be used?
Many sealants skin over quickly but take longer to cure fully. We’ll give you the cure time for the product we used before we leave.
What do you put in the joint?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we will explain our choice.
What should I tell you?
Only a few details: the address or postcode, what’s wrong and any access issues. After that, simply phone 0345 464 0079 or drop us an email.
Do you work at height?
It depends on the height and the site. Low-level joints are straightforward; for higher ones, send details and we’ll confirm the access.
What’s an expansion joint in brickwork?
Walls move with heat, cold and moisture, and planned joints take up that movement. The gap is sealed with a flexible sealant over backing rod.
Leave it or put it right?
Resealing a run of joints in one go is generally better than patching one at a time. Joints of the same age tend to fail together, and access only has to be arranged once. Converted houses in London often have a bathroom above someone else’s living room, and a slow leak from a failed seal can end up in the flat below. Putting it right early is much less trouble.
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Ask us for a quote and we will explain what it covers.
Why us?
- Over 20 years’ experience
- Sanitary silicone with an anti-fungal additive in wet areas
- We leave the area clean and tidy
- Old sealant always removed completely
See what affects the cost and our reviews.
DIY versus a professional finish
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
A DIY attempt does not rule out a professional job. We cut it out and start again, so tell us about it when you ask for a quote.
Nearby places to Hatch End
Also in Hatch End
When something else is needed
Before you book, it’s worth knowing the limits too:
- Adding movement joints to masonry that has none
- Cracks in the bricks or render themselves, away from the joints
- Damp that is not coming from the joint
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we will tell you honestly.
Joints and surfaces we work on
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Render & cladding joints
- Joints between brick and frames
- Façade panels