Kent · England
Greenhithe External Mastic
Sealing brickwork movement joints, render, cladding and façade joints in Greenhithe, with a one-year guarantee on every job. Ask us for a quote.
- Movement joints with cracked, split or missing sealant
- Old sealant gone brittle and cracked
- Joints where the bead has come unstuck
How we handle external mastic in Greenhithe
A movement joint is a deliberate break that lets a wall expand and contract. 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 are often asked to deal with panel joints letting water in and failed seals between different materials, on brickwork movement joints, façade panels and joints between brick and frames.
Around Greenhithe, garages, outbuildings and extensions all add to the joints on the outside of a home. Leaks normally start at a gutter end, a garage door frame or where an extension meets the house.
All our work comes with our one-year guarantee, wherever you are in Kent.
- Place
- Greenhithe (DA9, DA10)
- Region
- Kent
- Cover
- A year, on every job
- Price
- A clear price before we start
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Landlords, agents and businesses in Greenhithe
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together.
From a single let to a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
Places near Greenhithe
More services for Greenhithe
What affects the quote in Greenhithe
Your quote is based on your job. We look at:
- The number of rooms or windows
- Any working-time requirements on site
- How much old sealant there is and how hard it is to remove
- The size of the job
Some things make a job bigger or smaller: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
What we need to know
You don’t need to know the technical terms. Just tell us:
- How many joints, rooms or windows are involved
- Where the job is, and your postcode
- Whether it’s a home or a business
- Whether it has been sealed before
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is.
DIY sealant or a professional job?
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. Everything old must be removed first.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Outside joints around Greenhithe
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Schools such as Knockhall Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s. In the older streets around Church of St Mary, the joints between older walls, newer extensions and the roofline need a sealant that can move. If you let a flat or house near Greenhithe for Bluewater station, outside joints that have cracked can let damp into a rental, so check them between lets.
Greenhithe is about 3 miles east of Dartford, in Kent. Anywhere in DA9, we can carry out external mastic at your property. Greenhithe is one of 922 towns and villages in Kent where we work. London is on our list too, around 17 miles away.
Work in DA9 and DA10 is quoted and booked the same way as anywhere else. You will find streets such as Bean Road, The Avenue and Abbey Road. Greenhithe sits on or near the A206, which makes travel easy. If you’re just outside Greenhithe, we cover Swanscombe (1 mile south-east), Stone (1 mile south-west), Bean (2 miles south), West Thurrock (2 miles north) and Darenth (2 miles south-west). Larger places within reach include Dartford (3 miles west), Sevenoaks (12 miles south), Gravesend (4 miles east), Northfleet (3 miles south-east), Swanley (6 miles south-west) and Kings Hill (13 miles south-east).
What’s near Greenhithe
Locally, jobs take us to homes and businesses close to Castle Hill Park, The Ebbsfleet Academy and The White Hart Public House, among other places. Greenhithe has its own railway station: Greenhithe for Bluewater station. A little further out are Darent Valley Hospital (1.5 miles south-west) and Stone Museum of Geology (1.8 miles west). Open spaces near Greenhithe include Chafford Gorges Nature Park and Sawyers Lake.
What we can’t put right
We won’t take on work that will not last, so these are the limits:
- Rising or penetrating damp from elsewhere in the wall
- Cracking across the wall rather than at a joint
- Render that’s blown, hollow or coming away
If you’re not sure, just ring 0345 464 0079 or send us an email and we’ll give you a straight answer before you book.
Where we work in Greenhithe
- Copings & trims
- Façade panels
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Joints between brick and frames
Questions from Greenhithe
Can you do external mastic in Greenhithe?
Yes. We work across London and the South East, and Greenhithe is part of that. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear price.
Can you help a landlord with a rental near Greenhithe for Bluewater station?
Yes. We work for letting agents and landlords as well as homeowners. Just ring 0345 464 0079 or send us an email with the address and what needs doing, and we’ll give you a clear quote.
Where do you work from?
Mr Mastic is based in Crawley. Our applicators cover Greenhithe.
Will it make a mess?
No. We work neatly, protect the area around the joints and tidy up afterwards.
What colours does the sealant come in?
The aim is a neat, even joint in a colour that suits the wall. Colour is agreed with you before we begin, matched as closely as the range allows.
Can new sealant go over the old?
No. The old sealant always comes out first, so the new sealant bonds properly.
Can you reach joints on upper floors?
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.
When is the sealant fully cured?
It depends on the product. We tell you how long to leave it before we go.
Why act early in Greenhithe
It often makes sense to reseal all the failing joints on an elevation together. They’ve weathered the same way. In a smaller place like Greenhithe, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please ring 0345 464 0079 or drop us an email and we will talk you through it.
Why Greenhithe customers choose us
- Neat joints and a tidy finish
- More than 20 years in sealant work
- Trusted Arbo and Everbuild sealants
- An ARBOMaster approved applicator
Take a look at what affects the cost or customer reviews.
What happens on the day
Before we leave, we go over the finished joints with you and tell you how long to leave it. The work normally takes anything from a few hours to several days, depending on the building, depending on the size of the job. A visit to Greenhithe is planned like any other: the time, the access and where to park are agreed in advance. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
How to prepare
- Keep children and pets away from the work area
- Tell us about any previous sealing or DIY attempts
- For business premises, tell us about site rules or sign-in
How to get a quote
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll explain how we’d tackle it. When it suits you, ring 0345 464 0079 or email us.
Read more
Surface by surface
Render joints
Cracks along render joints let water in behind the coat. Resealing the joints early keeps water out.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. A flexible sealant bridges the two so the movement is taken up.