Kent · England
External Mastic in Darenth
External mastic in Darenth from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Brick movement joints where the sealant has split
- Plants rooting in failed movement joints
- Joints where the bead has come unstuck
Outside joints around Darenth
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. Historic houses like Hall Place and Gardens (about 4.6 miles north-west) are a reminder that the area around Darenth has older buildings as well as new. In older buildings, older brick and stone need a sealant that suits them, at the right joint depth.
For landlords with property near Farningham Road station, split movement joints are easy to miss on a rental until damp shows inside. If you live in an older home near Church of St Margaret of Antioch, the joints between older walls, newer extensions and the roofline need a sealant that can move.
Darenth is about 2 miles south-east of Dartford, in Kent. Every kind of property in Darenth is covered for external mastic, old or new, large or small. The work is guaranteed for a year. Across Kent, we cover 922 places, Darenth among them. For nearby work, see our London page.
All of DA2 is covered for external mastic. Whether your property is on Hill Rise, Hillside and Moss Way or anywhere close by, we can help. If you’re just outside Darenth, we cover St Margarets (1 mile south), Green Street Green (1 mile south-east), Sutton at Hone (1 mile south-west), South Darenth (1 mile south) and Bean (1 mile east). We also work in nearby towns such as Sevenoaks (10 miles south), Gravesend (5 miles east), Tonbridge (15 miles south), Northfleet (4 miles east), Swanley (4 miles south-west) and Kings Hill (12 miles south-east).
What’s near Darenth
Around Darenth, our work takes us to homes and buildings near Fox & Hounds pub, Darenth Country Park and Leigh Academy. For rail, the closest station is Farningham Road station, about 1.6 miles south-west. Well-known places in the area include Bluewater (1.5 miles north-east) and Darenth Park Hospital (1 mile north). Green spaces nearby include Wansunt Pit and Sawyers Lake.
About our external mastic in Darenth
External mastic is a job where short cuts show quickly. Overfilled joints, missing backing rod and sealant laid over old sealant rarely last long. We strip the joint back and start again. We work on façade panels, concrete & block and joints between brick and frames, and the jobs we see most are water getting into walls through failed joints and joints where the bead has come unstuck.
External sealant needs dry, clean surfaces, so work around Darenth is planned for dry weather. Tell us about access to all sides of the building, including outbuildings and garages.
Every job is covered by our 12-month guarantee, wherever you are in Kent.
- Location
- Darenth (DA2)
- Wider area
- Kent
- Guarantee
- One year on every job
- Quote
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Nearby places to Darenth
Other services in Darenth
DIY versus a professional finish
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
Quotes for external mastic in Darenth
Some jobs are bigger than they look, and some smaller. The main factors:
- Any mould that needs treating
- Any working-time requirements on site
- The type of sealant required
- The number of rooms or windows
The cost depends on the size of the job, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts.
What we need to know
There’s no need for technical detail. It helps if you can tell us:
- Any previous sealing or DIY work
- A few pictures by email, if you can
- Access, such as stairs, a lift or height
- Roughly how big the job is
Want a quote for external mastic? Please call 0345 464 0079 or email us and tell us about the job. We will explain what we’d do and give you a clear quote before work begins.
When to call us in Darenth
Poor preparation causes many early failures: dusty or wet faces, no primer where one was needed, or old sealant left in. The sealant never bonds properly.
The problems people generally mention when they call include:
- Movement joints filled with mortar instead of sealant
- Plants rooting in failed movement joints
- Damp patches traced to an open external joint
- Sealant that has lost its bond to the brick or render
Managing a site like Greenlands Primary School? Then larger buildings have long runs of movement joint that eventually need resealing.
Before you book anyone
- How the surfaces are prepared before sealing
- What insurance they hold
- What the quote includes, VAT included or not
- Whether they seal over old material or remove it
Darenth questions
Can you do external mastic in Darenth?
Yes. Our work covers London and the South East, and Darenth is part of that. Just ring 0345 464 0079 or email us with a few details of the job, and we’ll give you a clear quote.
I let a flat near Farningham Road station. Can you help?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before work begins.
Do the sealants smell?
There can be a smell while the sealant cures. Opening a window helps.
Are you ARBOMaster approved?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Can you reach joints on upper floors?
It depends on the building. Tell us the height, the number of joints and what’s below them, and we’ll confirm what access is needed.
Do you take out the old sealant first?
Yes. All of the old material is cut out and the joint cleaned.
Where do you work from?
We work from Crawley. We cover Darenth and the rest of Kent, along with the rest of our area.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
How it works
We bring everything the job needs with us. After a quick look at the joints together, we protect the area and start. It normally takes anything from a few hours to several days, depending on the building. Somewhere as small as Darenth, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by walking round the building and agreeing the joints and the access.
- Every bit of old sealant and any mortar or debris is cut out.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Tell us if parking is tricky
- Clear the area around the work
Get a quote
Call for a quick quote, or email us if that’s easier. Describe what needs sealing and we’ll explain what’s involved and give you a clear price.
Read more
Work for landlords, hotels and businesses
Letting agents often deal with us directly. Tell us the address, the job and how access works.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
What we cannot put right
To be straight with you, there are a few things sealant won’t fix:
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Cracked brickwork or render that needs a builder or plasterer
- Render that’s blown, hollow or coming away
Not sure which it is? You can ring 0345 464 0079 or send us an email and we’ll tell you honestly.
Surfaces we seal
- Joints between brick and frames
- Brickwork movement joints
- Render & cladding joints
- Façade panels
- Copings & trims
- Concrete & block
Keeping the joints in good condition
Aftercare is simple:
- Point out the joints to other trades
- Wash walls gently around the sealant
- Have failed joints looked at early
- Deal with leaking gutters that soak the joints below
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.
Act while the splits are small. At that stage it’s a simple cut out and reseal.