West Sussex · England
External & façade joints in Horsham, West Sussex
Specialist external mastic for Horsham: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Rigid filler in a joint that should flex
- Cracked joints where brick meets render or frames
- Movement joints with cracked, split or missing sealant
External mastic in Horsham
Failed sealant is cut out, the depth set with closed-cell backing rod, and the joint resealed with a low-modulus sealant made for outside. The colour is chosen to suit the brick or render so the joint doesn’t stand out. Typical jobs include cracked joints where brick meets render or frames and rain getting behind render or cladding at a joint, across copings & trims, concrete & block and façade panels.
Landlords and managing agents in Horsham have plenty of walls and rooflines to keep an eye on. The first sign is usually a dripping gutter end or a stain below a failed joint.
You are covered for a year from the day we finish. If anything is not right with it, phone 0345 464 0079 or send us an email.
- Place
- Horsham (RH12, RH13, RH20, BN44)
- Region
- West Sussex
- Cover
- One year on every job
- Quote
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What affects the quote in Horsham
The price is agreed before any work begins. It takes into account:
- When we can work, for business premises
- Mould in or behind the old joints
- Whether old sealant or filler has to be cut out
- The amount of work
The cost depends on the size of the job, how hard the old material is to remove and access to the work. We give a clear quote before work begins, so you know where you stand.
Helping us quote
To make quoting easier, let us know:
- The problem you’ve noticed
- Any access issues, like height or stairs
- Where the job is, and your postcode
- Photos by email, if that’s easy
Want a quote for external mastic? Please ring 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Nearby places to Horsham
Other services in Horsham
When to call us in Horsham
If plants are growing out of a joint, the sealant has usually failed or was never there. Roots and dirt hold water against the wall and speed up the damage.
People usually contact us after spotting one of these:
- Panel joints letting water in
- Weeds or debris growing in open joints
- Rain getting behind render or cladding at a joint
- Movement joints with cracked, split or missing sealant
In the older streets around Hope Chapel, an extension built onto an older house moves differently, and the joint between them takes the strain.
Questions to ask before you book
- Whether the sealant suits the joint
- What guarantee comes with the work
- How much experience the applicator has
- What the quote includes, VAT included or not
What we do, step by step
We keep the work tidy and contained to the joints we are treating, so you can get on with your day. The job generally takes a few hours for a handful of joints, longer for a whole elevation. Commercial jobs in Horsham can be planned out of hours where a building cannot close, while home visits are arranged within our normal working hours, Monday to Saturday.
- We look at every joint and agree a colour to suit the wall.
- Failed sealant is removed back to clean, sound faces.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
How to prepare
- Clear items away from the joints we are working on
- Let us know about stairs, lifts or work at height
- Keep pets and children clear of the area while we work
Getting a quote
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.
Related advice
What external mastic looks like in Horsham
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.
For landlords with property near Horsham station, split movement joints are easy to miss on a rental until damp shows inside.
Horsham is about 31 miles south of London, in West Sussex. For external mastic in and around Horsham, it’s easy to get a quote: please call 0345 464 0079 or drop us an email. We cover West Sussex from our Crawley base. Across West Sussex, we cover 371 places, and Horsham is one of them. We also work in Crawley, about 7 miles from Horsham.
Work in RH12, RH13, RH20 and BN44 is quoted and booked the same way as anywhere else. Streets in the area include Station Road, London Road and Market Square. Horsham is on the A24 and A29, which makes it straightforward to reach. Neighbouring places we cover for external mastic include Tower Hill (1 mile south-west), Broadbridge Heath (2 miles west), Holbrook (2 miles north), Warnham (2 miles north-west) and Southwater (3 miles south). Larger places within reach include Crawley (7 miles north-east), Haywards Heath (11 miles south-east), Burgess Hill (11 miles south-east), East Grinstead (14 miles east), Broadfield (5 miles east) and Storrington (11 miles south-west). As one of the bigger places in West Sussex, Horsham has homes, rented property and businesses of every kind.
Landmarks near Horsham
Locally, jobs take us to homes and businesses close to Millais School, Warnham Park and Kingslea Primary School, among other places. Horsham has its own railway station: Horsham station. Well-known places in the area include Christs Hospital School Museum (2.4 miles south-west) and Horsham Hospital (within half a mile north-west). For a walk, there’s Warnham LNR.
How the job changes by surface
Cladding and façade panels
If the façade has a specified sealant, that’s what we use. Send us any details you have about the façade.
Concrete and blockwork
The face of concrete or block is often dusty, so preparation is key. A primer goes on where the product requires one before sealing.
What happens if it’s left?
Resealing a run of joints in one go is generally better than patching one at a time. They’ve weathered the same way. Busy buildings in Horsham, from hotels to offices, cannot afford rooms out of use for leaks or mould, so failing joints are best replaced on a planned basis.
Doing several joints on one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Why book with us
- Approved under the ARBOMaster scheme
- Arbo and Everbuild products
- We never seal over old sealant
- Anti-fungal silicone where joints get wet
When something else is needed
Some problems need a builder, plumber or other trade rather than us:
- Loose or hollow render, which needs re-rendering
- Cutting new joints into brickwork, which is building work rather than sealant work
- Cracked brickwork or render that needs a builder or plasterer
If in doubt, phone 0345 464 0079 or send us an email and we’ll say what we think.
Where we work in Horsham
- Joints between brick and frames
- Brickwork movement joints
- Façade panels
- Render & cladding joints
- Copings & trims
- Concrete & block
Landlords, agents and businesses in Horsham
For anyone letting property in or around Horsham, several properties can be quoted together. Just tell us the addresses and what each one needs.
Housing providers, facilities teams and property managers book us too in Horsham and across West Sussex. Several sites can be quoted together, and we’re fully insured.
Questions from Horsham
What guarantee comes with external mastic in Horsham?
All our work, in Horsham and everywhere else, comes with a 12-month guarantee. We’re fully insured, and an ARBOMaster approved applicator.
Is Horsham in your area for external mastic?
Yes. Our work covers London and the South East, and Horsham is part of that. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we will send you a clear quote.
Do you work for landlords and businesses?
Yes, we do. Domestic, commercial and hotel work are all part of what we do.
Will there be a smell?
It depends on the product. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Is it OK to fill a movement joint with cement?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose, and the wall may crack nearby. A flexible sealant is the right fill.
How long does external mastic last?
That varies with the weather the wall faces, how much it moves and the sealant used. Sealant is a maintenance item, so check the joints once a year and reseal when it splits.
Can you seal over the old sealant?
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.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.