East Sussex · England
External Mastic in Blacklands
Specialist external mastic for Blacklands: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Gaps where render, brick and frames meet
- Failed sealant between panels on a façade
- Joints with sealant missing in places
What we do, step by step
When we arrive, we look over the joints with you first. Surfaces next to the work are protected before any work begins. The work normally takes a few hours to a few days, depending on the length of joint and the access. A visit to Blacklands is planned like any other: the time, the access and where to park are agreed in advance. Outdoor jobs depend on a dry day, since 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.
- Primer is applied wherever the sealant needs it.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- For indoor joints, keep the area dry beforehand if you can
- For business premises, tell us about site rules or sign-in
- Keep pets and children clear of the area while we work
Getting a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll explain how we’d tackle it. Whenever you’re ready, phone 0345 464 0079 or email us.
Advice
External mastic for homes and businesses in Blacklands
Movement joints let brickwork, render and cladding expand and shrink without cracking. The sealant in it has to stretch and squeeze for years, and when it fails, the wall takes the strain and water finds a way in. We work on concrete & block, façade panels and joints between brick and frames, and the jobs we see most are cracked joints where brick meets render or frames and sealant pulling away from one side of the joint.
Homes around Blacklands range from older cottages to newer houses, with walls and rooflines of every type. Older homes need their gutter and trim joints kept tight, newer ones their movement joints.
There’s a 12-month guarantee on every job.
- Place
- Blacklands (TN34, TN37, TN35)
- Region
- East Sussex
- Cover
- A year, on every job
- Quote
- A clear price before any work starts
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What happens if it’s left?
A failed movement joint lets water into the wall, behind render and cladding. Resealing early keeps the job to the joint itself, rather than the wall around it. In an older home around Blacklands, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you are not sure whether it needs doing, ring 0345 464 0079 or drop us an email for an honest opinion and a quote.
Why Blacklands customers choose us
- You choose the colour before work begins
- Approved under the ARBOMaster scheme
- Fully insured
- Over 20 years’ experience
See our cost guide and our reviews.
Landlord and commercial work in Blacklands
We also work for property managers and facilities teams in Blacklands and across East Sussex. We can quote a run of properties together.
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.
Signs you need external mastic in Blacklands
Every building moves. Clay bricks expand slightly over their life, concrete and block shrink, and everything moves with temperature and wet. The sealant in the movement joints takes that strain.
Look out for these signs:
- Gaps where render, brick and frames meet
- Rigid filler in a joint that should flex
- Plants rooting in failed movement joints
- Sealant that has lost its bond to the brick or render
If you live in an older home near Christ Church, older walls, gutters and the joints where extensions meet them need a flexible sealant.
Questions to ask before you book
- Who turns up on the day
- Which colour the sealant will be
- Which sealant they’ll use, and why
- Whether they’re fully insured
Blacklands: your questions answered
Is external mastic in a coastal place like Blacklands any different?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. The right product, a clean joint and the right depth all help it cope.
Do you work for landlords with property near Ore station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or send us an email and tell us about the property, and we’ll send you a clear quote.
Where is Mr Mastic based?
We’re a Crawley-based firm, with over 20 years’ experience. Our area covers South East England, London and Scotland.
Can you seal joints between render and window frames?
Yes. The old joint is removed, both surfaces cleaned and primed where needed, and a flexible sealant applied. We pick a colour that works with both materials.
Is it OK to fill a movement joint with cement?
No. Mortar locks the joint solid, so the wall cracks somewhere else instead. It needs a flexible sealant over backing rod.
Do you work at height?
That depends on the building and the joints. We work on joints that can be reached safely. Give us some details and we will confirm the access.
Are you ARBOMaster approved?
Yes. We hold ARBOMaster approved applicator status and we’re fully insured too.
Can you match the colour of my brickwork?
We aim for a joint that suits the wall rather than one that jumps out. Colour is agreed with you before we begin from the range available.
DIY sealant or a professional job?
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Quotes for external mastic in Blacklands
Every job gets its own quote. This is what makes a difference:
- Any working-time requirements on site
- Whether the work is at height
- Whether there’s mould to deal with
- How much there is to do
We do not show prices on the website, because the cost depends so much on the job itself. Call for a quick quote and we will talk you through it.
Asking for a quote
To help us quote quickly, let us know:
- Where the property is
- How we’d reach the joints
- If someone has resealed it before
- Roughly how big the job is
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, and email photos if that’s easy.
Outside joints around Blacklands
Blacklands is within about 1 mile of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That is hard on movement joints and outside wall joints, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
Schools such as Ark Blacklands Primary Academy are buildings too, and larger buildings have long runs of movement joint that eventually need resealing. If you let a flat or house near Ore station, failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Blacklands is about 1 mile east of Hastings, in East Sussex. Jobs in Blacklands get the same care as everywhere else we work: old sealant removed completely, careful preparation and a one-year guarantee. Blacklands is one of 289 places in East Sussex we cover. We also work in Brighton, around 31 miles away.
All of TN34, TN37 and TN35 is within our area for external mastic, from the main roads to the quietest streets. Whether your property is on Laton Road, Manor Road and Park Avenue or a nearby road, we can help. With the A2101 close by, Blacklands is simple for us to get to. We also cover the places around Blacklands: St Helen's (1 mile north), Hastings (1 mile west), Belmont (1 mile south-east), America Ground (1 mile south) and Hastings Old Town (1 mile south-east). Within a short drive, we also cover Eastbourne (14 miles south-west), Bexhill-on-Sea (5 miles west), Hailsham (14 miles west), Polegate (15 miles west), Old Town (15 miles south-west) and Upper Horsebridge (14 miles west).
Local landmarks in Blacklands
We work in homes and buildings around William Parker Sports College, Roman Catholic Church of St Mary Star of the Sea and Alexandra Park. Other local landmarks include University School (0.8 miles south) and Crowleys Bar (0.7 miles south). The closest station to Blacklands is Ore station, roughly 0.6 miles east of the centre. Well-known places in the area include The True Crime Museum (0.9 miles south) and Priory Meadow Shopping Centre (0.7 miles south). Not far away are Church Wood and Robsack Wood.
Surface by surface
Render joints
Render is weaker at the surface than brick, so a sealant that stretches easily protects the edges. We prime where the product needs it.
Copings and trims
Copings expand and contract through the day, so the joints need a sealant that stays flexible in all weathers.