East Sussex · England
Northiam External Mastic
Movement joints in Northiam need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Water getting into walls through failed joints
- Hard, crazed mastic that has stopped moving
- Rigid filler in a joint that should flex
About our external mastic in Northiam
Movement joints let brickwork, render and cladding expand and shrink without cracking. 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. If you have sealant pulling away from one side of the joint and panel joints letting water in, we can put it right, whatever the surface.
In a village or hamlet like Northiam, older cottages and farm buildings often stand in the open, 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.
We guarantee the work for a year. If there’s a problem with our work within the year, let us know and we’ll sort it.
- Location
- Northiam (TN31)
- Wider area
- East Sussex
- Cover
- One year on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Common questions in Northiam
Is Northiam in your area for external mastic?
Yes. Our work covers London and the South East, and Northiam is part of that. Just ring 0345 464 0079 or email us with a few details of the job.
Is there a guarantee on external mastic in Northiam?
All our work, in Northiam and everywhere else, comes with a 12-month guarantee. We are also fully insured and ARBOMaster approved.
How do you reach high-level joints?
That depends on the building and the joints. Where joints can be reached safely, we’ll do them. Give us some details and we will confirm the access.
Do you work for hotels and businesses?
Yes, regularly. Larger jobs can be planned room by room or area by area.
Why do you put foam in the joint first?
We fit closed-cell backing rod wherever the joint depth needs controlling. It controls the depth and stops the sealant bonding to the back so the bead can stretch.
Do the sealants smell?
Sometimes, a little. It fades as the sealant cures.
Can new sealant go over the old?
No, it will not last. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
Can landlords and businesses book you?
Yes, we do. Domestic, commercial and hotel work are all part of what we do, and we are fully insured.
Outside joints around Northiam
With historic houses such as Great Dixter (about 0.5 miles west) nearby, there’s older building stock in the area around Northiam as well as newer homes. Where a home is older, older brick and stone need a sealant that suits them, at the right joint depth. The South East is one of the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you look after a building such as Northiam Church of England Primary School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Northiam is about 9 miles north of Hastings, in East Sussex. Anywhere in TN31, we can carry out external mastic at your property. Northiam is one of 289 towns and villages in East Sussex where we work. Our Brighton page covers work nearby, about 34 miles away.
Jobs for external mastic in TN31 is quoted and booked the same way as anywhere else. You will find streets such as Station Road, Main Street and Elizabeth Gardens. Main roads around Northiam include the A268. If you’re just outside Northiam, we cover Beckley (2 miles south-east), Beckley Furnace (3 miles south), Broad Oak (3 miles south), Flackley Ash (3 miles east) and Broadland Row (4 miles south). Further out, we also cover Hastings (9 miles south), Bexhill-on-Sea (12 miles south-west), St Leonards (10 miles south), Hastings Old Town (10 miles south), Belmont (10 miles south) and Heathfield (15 miles west).
Landmarks near Northiam
Around Northiam, our work takes us to homes and buildings near Hayes Arms Hotel and the streets around them. Well-known places in the area include The C.M Booth Collection (4 miles north). The countryside around Northiam includes Flatropers Wood.
What we can’t put right
Sealant is not the answer to every problem, and we’ll tell you before we start. It won’t solve:
- Cracked brickwork or render that needs a builder or plasterer
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Walls that need new movement joints cut into them
If in doubt, ring 0345 464 0079 or send us an email and we will say what we think.
Where we work in Northiam
- Joints between brick and frames
- Brickwork movement joints
- Copings & trims
- Concrete & block
- Render & cladding joints
- Façade panels
Leave it or put it right?
It often makes sense to reseal all the failing joints on an elevation together. They’ve weathered the same way, and access only has to be arranged once. Around Northiam, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
The cost depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts.
Why choose Mr Mastic in Northiam
- ARBOMaster approved applicator
- Anti-fungal silicone where joints get wet
- More than 20 years in sealant work
- Quality sealants from Arbo and Everbuild
Read our cost guide or customer reviews.
How the visit works
A visit follows a simple pattern: we look at the joints together, protect the area around them, carry out the job and clear up. It usually takes a few hours for a handful of joints, longer for a whole elevation. Somewhere like Northiam needs a little journey planning: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- We start by walking round the building and agreeing the joints and the access.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Preparing for the visit
- Mention any tricky access
- Tell us about any previous sealing or DIY attempts
- For business premises, tell us about site rules or sign-in
Getting a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and email pictures if that is easy.
Advice
Aftercare tips
Good habits help new joints last longer. Our tips:
- Keep movement joints as flexible joints, not mortar
- Do not let climbing plants root in the sealant
- Fix overflowing gutters above sealed joints
- Avoid pressure-washing directly into sealant joints
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Water getting behind cladding or render can go unnoticed for a long time. When it finally shows inside, the joint may have been open for years, so it’s worth resealing at the first signs.
How the job changes by surface
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. The old joint is removed and a sealant that bonds to both sides goes in.
Concrete and blockwork
Big joints in concrete need careful depth control. Backing rod sized to the joint sets it.
Towns and villages near Northiam
What else we do in Northiam
What we are called out for in Northiam
Sunlight, wet weather and frost wear exterior sealant down. In time it goes hard, crazes on the surface and stops stretching, so the joint eventually tears or comes away from one side.
People normally contact us when they notice something like this:
- Sealant pulling away from one side of the joint
- Joints pointed up with cement by mistake
- Water getting into walls through failed joints
- Leaking joints around cladding and façade panels
Great Dixter, about 0.5 miles west, is one of the historic houses in the wider area around Northiam, and older homes nearby need a sealant that suits their walls.
What your quote should include
- How the surfaces are prepared before sealing
- Are they insured?
- Whether the sealant suits the joint
- Whether VAT is included
DIY versus a professional finish
Some jobs are best left to a professional: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
If you do try it yourself, take your time over the preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.