Kent · England
External Mastic in Underling Green
Sealing brickwork movement joints, render, cladding and façade joints for Underling Green, backed by a one-year guarantee. Ask us for a quote.
- Failed sealant between panels on a façade
- Moss and dirt in joints with no sealant left
- Joints with sealant missing in places
External mastic for homes and businesses in Underling Green
We’re ARBOMaster approved applicators, and each external joint gets a sealant suited to it. Porous or awkward surfaces are primed where the sealant needs it and we use one wherever it does. If you have rigid filler in a joint that should flex and movement joints with cracked, split or missing sealant, we can put it right.
Older homes in small places like Underling Green may be stone, brick or timber-framed, often with later extensions. Where one material meets another is where water usually gets in.
Each job carries a 12-month guarantee.
- Where
- Underling Green (TN12)
- Wider area
- Kent
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
For landlords and businesses
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Landlords and letting agents in Underling Green can book us as well as householders. Sealant work between tenants keeps a property looking cared for.
When it isn’t the sealant
To be straight with you, some problems need a different trade:
- Cracking across the wall rather than at a joint
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Failed render or damaged cladding panels
Not sure which it is? You can ring 0345 464 0079 or email us and we’ll tell you honestly.
Where we work in Underling Green
- Brickwork movement joints
- Façade panels
- Render & cladding joints
- Copings & trims
- Joints between brick and frames
- Concrete & block
Aftercare tips
After the cure time, these simple habits help:
- Fix overflowing gutters above sealed joints
- Tell anyone working on the walls about the movement joints
- Wash walls gently around the sealant
- Ask before painting over external sealant
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.
Leaks behind façade panels and render often go unseen. When it finally shows inside, the joint may have been open for years.
Different surfaces, different methods
Render joints
Render is weaker at the surface than brick, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
Joints between dissimilar materials
Brick against render, concrete against metal, stone against timber: every change of material is a joint. We seal the joint with a flexible exterior sealant so neither cracks the other.
Signs you need external mastic in Underling Green
Sometimes a movement joint was filled with mortar or a rigid filler by mistake. The joint cannot move, so the wall cracks somewhere else instead.
These are the problems we’re asked about most:
- Leaking joints around cladding and façade panels
- Damp patches traced to an open external joint
- Hard, crazed mastic that has stopped moving
- Brick movement joints where the sealant has split
For landlords with property near Marden station, split movement joints are easy to miss on a rental until damp shows inside.
Questions to ask before booking
- When the joint can take water or movement
- Which colour the sealant will be
- How hidden problems are handled
- Which sealant they’ll use, and why
Places near Underling Green
Other services in Underling Green
How it works
Most of a good job is in the preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. In total, it generally takes a few hours for a handful of joints, longer for a whole elevation. Somewhere as small as Underling Green, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, the joints are inspected and the access agreed.
- 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.
- We fit closed-cell backing rod to control the depth.
- We apply the sealant, tool it and check the whole run.
Before we arrive
- Let us know about parking restrictions
- For indoor joints, keep the area dry beforehand if you can
- Mention any tricky access
Getting a quote
If you’re in Underling Green and need external mastic, call 0345 464 0079 or drop us an email. Tell us what the problem is and where, and we will agree the price before any work begins.
Related advice
Walls and rooflines in Underling Green
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Stoneacre (about 5 miles north-east) nearby, there’s older building stock in the area around Underling Green as well as newer homes. In older buildings, older walls and rooflines need a sealant that moves with them and suits the material.
Stoneacre, about 5 miles north-east, is one of the historic houses in the wider area around Underling Green, and older homes nearby need a sealant that suits their walls.
Underling Green is about 5 miles south of Maidstone, in Kent. From the centre of Underling Green to the outskirts, external mastic is available for homes and businesses alike. We cover 922 towns and villages across Kent. For nearby work, see our Crawley page.
Jobs for external mastic in TN12 is quoted and booked the same way as anywhere else. We also cover Milebush (1 mile south-west), St Ann's Green (1 mile south), Wanshurst Green (1 mile south), Cross-at-Hand (1 mile east) and Rabbit's Cross (2 miles east). Further out, we also cover Maidstone (5 miles north), Sittingbourne (14 miles north-east), Sevenoaks (15 miles north-west), Royal Tunbridge Wells (11 miles west), Tonbridge (10 miles west) and Kings Hill (7 miles north-west).
Near you in Underling Green
Underling Green’s nearest station is Marden station, about 1.5 miles south-west of the centre. Well-known places in the area include Oakwood Hospital (5.5 miles north) and South East Romany Museum (1.3 miles south).
Questions from Underling Green
Can you do external mastic in Underling Green?
Yes, Underling Green is within the area we cover. We work across London and the South East. You can call 0345 464 0079 or send us an email and let us know what needs doing.
Is Underling Green within the area you cover?
Yes. Underling Green is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do I have to be there?
We need access to the joints, so we’ll agree that with you when we book. For inside work, that normally means someone being in.
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.
What does external mastic cost?
The cost depends on the size of the job, access and how much old sealant has to come out. Ask us for a quote.
Why is there a gap in my brick wall?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It’s sealed with a flexible sealant, not mortar.
What colours does the sealant come in?
There’s a good range of exterior colours, including greys, browns, whites and stone tones. We pick the one that suits your wall best so it does not stand out.
Is the work guaranteed?
Yes: twelve months. If there’s a problem with our work in that time, tell us and we will put it right.
Why act early in Underling Green
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Where a wall is exposed, as many are in small places like Underling Green, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
What you get with us
- We never seal over old sealant
- White, clear, grey or coloured to suit, where the product allows
- Sealant colour chosen to suit
- An ARBOMaster approved applicator
Read how sealant jobs are priced and our reviews.