Kent · England
Clement Street External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Clement Street and across Kent. Fully insured, ARBOMaster approved and guaranteed for a year.
- Plants rooting in failed movement joints
- Movement joints filled with mortar instead of sealant
- Movement joints with cracked, split or missing sealant
External mastic for homes and businesses in Clement Street
A movement joint is only as good as its depth. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, so it bonds to the two sides only and can stretch. If you have water getting into walls through failed joints and leaking joints around cladding and façade panels, we can help, on render & cladding joints, concrete & block and copings & trims alike.
Somewhere as small as Clement Street, homes and farm buildings often face open ground, so walls and rooflines take the full force of wind and rain. Gutter joints and wall joints there need a sealant that can flex and stay put.
Our work is backed for twelve months.
- Location
- Clement Street (BR8)
- Wider area
- Kent
- Guarantee
- A year, on every job
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
What external mastic looks like in Clement Street
Historic houses like Hall Place and Gardens (about 3.3 miles north-west) are a reminder that the area around Clement Street has older buildings as well as new. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For an older house near a landmark such as Church of Saint Paul, older walls, gutters and the joints where extensions meet them need a flexible sealant. Rented homes near Farningham Road station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Clement Street is about 2 miles south of Dartford, in Kent. Whether you’re in the middle of Clement Street or further out, we cover external mastic for every kind of property, from flats and houses to offices and hotels. Our area takes in 922 places across Kent, large and small. There’s also a page for London, about 14 miles away.
Here we cover the BR8 postcode area for external mastic. We also cover the places around Clement Street: Hawley (1 mile north-east), Sutton at Hone (1 mile east), South Darenth (2 miles south-east), Darenth (2 miles east) and St Margarets (2 miles east). We also work in nearby towns such as Sevenoaks (9 miles south), Gravesend (7 miles east), Tonbridge (15 miles south), Northfleet (6 miles east), Kings Hill (13 miles south-east) and Swanscombe (4 miles north-east).
Landmarks near Clement Street
Locally, jobs take us to homes and businesses close to Dartford Heath, Wilmington Academy and The Plough pub and the streets around them. The closest station to Clement Street is Farningham Road station, about 1.3 miles south-east of the centre. Well-known places in the area include Eynsford Castle (3 miles south) and West Hill Hospital (2.2 miles north). Not far away are Wansunt Pit.
Quotes for external mastic in Clement Street
Call for a quick quote. The main things that affect it are:
- Working hours on commercial sites
- Any mould that needs treating
- How many rooms, windows or areas are involved
- The type of sealant required
Leaving a failed joint usually makes the job bigger, not smaller, because water and mould keep working on it. If you’re not sure whether it needs doing, call 0345 464 0079 or drop us an email for an honest opinion and a quote.
What we need to know
Photos by email are helpful but not essential. Try to tell us:
- What the problem is, such as mould, gaps, leaks or cracking
- How many joints, rooms or windows are involved
- Whether it has been sealed before
- A few photos by email, if you can
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. Whenever you are ready, call 0345 464 0079 or email us.
Work for landlords, hotels and businesses
Hotels need rooms back in use, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
For anyone letting property in or around Clement Street, jobs at different addresses can go on one quote. Just tell us the addresses and what each one needs, and photos by email help.
Towns and villages near Clement Street
What else we do in Clement Street
What happens on the day
Once we are on site, 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. For a village or hamlet like Clement Street, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each joint, agreeing the ones to redo and how we will reach them.
- Old sealant and any debris are cut and raked out.
- The joint faces are cleaned and primed where the sealant needs it.
- We push in closed-cell backing rod so the sealant is the right depth and bonds to the sides only.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Before we arrive
- Move anything stored near the joints
- Let us know about parking restrictions
- Plan for the work area to be out of bounds to pets and children
Getting a quote
Want a quote for external mastic? Please ring 0345 464 0079 or drop us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Read more
Do you need external mastic in Clement Street?
Some movement joints have been pointed up with mortar, often by someone who didn’t know what it was for. The joint can’t move, so the wall cracks somewhere else instead.
People normally contact us after spotting something like this:
- Joints pointed up with cement by mistake
- Panel joints letting water in
- Sealant that has lost its bond to the brick or render
- Moss and dirt in joints with no sealant left
Schools such as Sutton-At-Hone Church of England Primary School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
Before booking anyone
- What preparation is included
- How long to leave it before use
- Whether the sealant suits the joint
- Which colour the sealant will be
What we can’t put right
New sealant can’t fix everything, and we’d rather say so up front. Sealant will not put right:
- Cracked brickwork or render that needs a builder or plasterer
- Failed render or damaged cladding panels
- Movement that’s more than a sealant joint can take
Not sure which it is? You can phone 0345 464 0079 or send us an email and we will tell you honestly before booking.
What we seal
- Brickwork movement joints
- Joints between brick and frames
- Render & cladding joints
- Concrete & block
- Copings & trims
- Façade panels
Clement Street: your questions answered
Can you do external mastic in Clement Street?
Yes, Clement Street is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and let us know what needs doing.
Is Clement Street within the area you cover?
Yes. Clement Street is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.
Do you work for hotels and businesses?
Yes. We have worked for hotels, offices and other businesses.
Should I point up the gap in my brickwork?
No. Cement or mortar can’t stretch and the joint fails. If it has already been filled, we can usually cut it out and reseal it.
Where are you based?
We are based in Crawley, West Sussex, and we work across South East England, London and Scotland.
Will the new joint stand out?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We choose the closest to your brick or render.
Can you seal over the old sealant?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. We remove it all first.
DIY sealant or a professional job?
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
How the job changes by surface
Joints between dissimilar materials
Where a frame or panel meets masonry, water often finds a way in. The old joint is removed and a sealant that bonds to both sides goes in.
Brickwork movement joints
Vertical joints in long brick walls let the brickwork expand without cracking. They’re resealed over backing rod with a low-modulus sealant in a colour to suit the brick.