East Sussex · England
External Mastic in Blackboys
External mastic in Blackboys from a team with over 20 years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Leaking joints around cladding and façade panels
- Hard, crazed mastic that has stopped moving
- Weeds or debris growing in open joints
How to look after the new joints
After the cure time, these simple habits help:
- Never let anyone fill a movement joint with mortar
- Look over the joints every year, ideally after winter
- Deal with leaking gutters that soak the joints below
- Keep soil, plants and ivy away from the joints
Look over the joints once a year, ideally after winter. Splits, gaps at the edges or plants in the joint are early warning signs.
Once a joint can’t move, the wall finds another way, normally as cracking in the brickwork or render nearby. Catch it early and you reduce the risk.
External mastic in Blackboys, done properly
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Some surfaces need a primer before sealing. We work on render & cladding joints, brickwork movement joints and joints between brick and frames, and the jobs we see most are brick movement joints where the sealant has split and leaking joints around cladding and façade panels.
Outside joints can only be sealed when they’re dry, so work in Blackboys is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
A one-year guarantee comes with the work, just as it does everywhere we cover.
- Where
- Blackboys (TN22)
- Region
- East Sussex
- Cover
- A year, on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Also near Blackboys
More services for Blackboys
Work for landlords, hotels and businesses
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance that we can handle for you.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can be quoted together.
External mastic in Blackboys: local notes
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Rented homes near Buxted station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies.
Blackboys is about 3 miles east of Uckfield, in East Sussex. If you need external mastic in Blackboys, please ring 0345 464 0079 or send us an email for a quick quote. We’re based in Crawley and cover East Sussex, Blackboys included. Blackboys is one of 289 places in East Sussex where we work for external mastic. Our Brighton page covers work nearby.
Work in TN22 works the same way as everywhere else we cover. That includes homes and businesses on High Street, Mount Pleasant and Gun Road and the roads around them. Blackboys is on the B2102, so it’s easy for us to get to with everything needed for external mastic. Neighbouring places we cover for external mastic include Etchingwood (1 mile north-west), Framfield (1 mile west), Potter's Green (2 miles north-west), Buxted (2 miles north-west) and Hadlow Down (2 miles north). Larger places within reach include Eastbourne (13 miles south-east), Bexhill-on-Sea (15 miles south-east), Seaford (13 miles south), Lewes (9 miles south-west), Hailsham (8 miles south-east) and Crowborough (6 miles north).
Around Blackboys
In Blackboys, that means homes and buildings near Blackboys Inn and Passingworth Park and the streets around them. The nearest railway station is Buxted station, about 2.3 miles north-west. A little further out are Uckfield Community Hospital (2.6 miles west) and Sussex Farm Museum (3.9 miles south-east). For a walk, there’s Selwyns Wood.
What sealant work can’t fix
It helps to know what we can’t do:
- Damp that isn’t coming from the joint
- Subsidence or other structural problems
- Cracked brickwork or render that needs a builder or plasterer
If you are not sure, just call 0345 464 0079 or drop us an email and we will give you a straight answer before booking.
Surfaces we seal
- Render & cladding joints
- Joints between brick and frames
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Façade panels
Questions from Blackboys
Do you cover Blackboys for external mastic?
Yes, Blackboys is within the area we cover. We work across London and the South East. You can ring 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear quote.
I let a flat near Buxted station. Can you help?
Yes, we work for landlords and agents. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Do you do commercial work?
Yes. We work in offices, washrooms, hotels and other commercial premises. Working times can be discussed when we quote.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Can you seal joints between render and window frames?
Yes. Materials like render, brick, metal and uPVC all move differently, so a flexible sealant is needed where they meet. We choose one that suits both surfaces.
When is the sealant fully cured?
Different products cure at different speeds, so follow the cure time we give you when we finish.
Can I do it myself?
For a simple, easy-to-reach joint, a careful DIYer can do a reasonable job. Most DIY failures come from sealing over old material, wet joints or too much sealant.
How much does external mastic cost in Blackboys?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote.
What we do, step by step
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours for a handful of joints, longer for a whole elevation, and the area is left clean. Somewhere like Blackboys needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- 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.
Preparing for the visit
- Move anything stored near the joints
- Keep children and pets away from the work area
- Tell us if parking is tricky
Ask for a quote
We quote each job on its own. Just phone 0345 464 0079 or email us with the details, and pictures are welcome.
Advice
Signs you need external mastic in Blackboys
Some movement joints have been pointed up with mortar. With the joint locked solid, the movement turns into cracks elsewhere in the wall.
Look out for these signs:
- Joints with sealant missing in places
- Moss and dirt in joints with no sealant left
- Leaking joints around cladding and façade panels
- Gaps where render, brick and frames meet
Managing a site like Blackboys Church of England Primary School? Then its movement joints, gutters and trims need looking after like any other building’s.
What to look for in a quote
- How hidden problems are handled
- What the quote includes, VAT included or not
- Whether you can choose the colour
- Whether all the old sealant comes out first
Can I do it myself?
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. All the old material has to come out first.
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 does not work out, we can still put it right.
What the job involves on each surface
Brickwork movement joints
Brick movement joints are often mistaken for a missing mortar line. If that’s happened, we rake it out and reseal it properly if the joint can be cleared.
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.