West Sussex · England
External Mastic in Crawley Down
Our applicators work in Crawley Down on sealing brickwork movement joints, render, cladding and façade joints. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Failed sealant between panels on a façade
- Joints with sealant missing in places
- Cracked joints where brick meets render or frames
What we’re called out for in Crawley Down
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.
Most people get in touch after spotting something like this:
- Movement joints with cracked, split or missing sealant
- Sealant that has lost its bond to the brick or render
- Failed seals between different materials
- Weeds or debris growing in open joints
Rented homes near East Grinstead station change hands often, and outside joints that have cracked can let damp into a rental, so check them between lets.
Before booking anyone
- How hidden problems are handled
- Are they insured?
- Is the old sealant removed completely?
- What product goes in the joint
How we handle external mastic in Crawley Down
Joints between dissimilar materials, like brick against render or concrete against a steel frame, see movement from both sides. A flexible exterior sealant takes up that movement. If you’re dealing with plants rooting in failed movement joints and panel joints letting water in, we can put it right, on joints between brick and frames, concrete & block and façade panels alike.
In a smaller place like Crawley Down, some homes face open ground, so exposed walls and rooflines take more wind-driven rain. That is where gutter joints and wall joints tend to fail first.
You’re covered for a year from the day we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Location
- Crawley Down (RH10)
- Wider area
- West Sussex
- Cover
- A year, on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Also near Crawley Down
Other services in Crawley Down
Walls and rooflines in Crawley Down
With historic houses such as Saint Hill Manor (about 2.4 miles south-east) nearby, there’s older building stock in the area around Crawley Down as well as newer homes. Where a home is older, older walls and rooflines need a sealant that moves with them and suits the material. 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 an older house near a landmark such as All Saints Parish Church, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
Crawley Down is about 3 miles west of East Grinstead, in West Sussex. Homes, rented property, offices and hotels in Crawley Down is covered for external mastic. Every job comes with our one-year guarantee. Our West Sussex coverage runs to 371 places, Crawley Down among them.
Work in RH10 works the same way as everywhere else we cover. We cover properties on Station Road, Forest Close and Burleigh Way. Close by, we work in Furnace Wood (1 mile north), Snow Hill (1 mile north), Turners Hill (1 mile south), Domewood (1 mile north) and Felbridge (2 miles north-east). We also work in nearby towns such as Crawley (5 miles west), Horsham (11 miles west), Haywards Heath (9 miles south), Burgess Hill (12 miles south), East Grinstead (3 miles east) and Broadfield (6 miles west).
What’s near Crawley Down
Around Crawley Down, our work takes us to homes and buildings near Imberhorne School, among other places. The nearest railway station is East Grinstead station, about 2.5 miles east. A little further out are Queen Victoria Hospital (3.5 miles east) and Effingham Park Motor Museum (1.4 miles north-west). For a walk, there’s Hedgecourt Lake.
Landlords, agents and businesses in Crawley Down
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
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.
Common questions in Crawley Down
Can you help a landlord with a rental near East Grinstead station?
Yes, rental work is part of what we do. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before we start.
Will you come out to Crawley Down?
Yes. Crawley Down 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.
What is backing rod for?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only.
Why is there a gap in my brick wall?
Brickwork, render and cladding all move a little, so long walls have planned gaps to take that movement. It’s closed with backing rod and a flexible sealant.
How long does the job take?
It depends on the size of the job, but most jobs take anything from a few hours to several days, depending on the building. We will tell you when we quote.
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. The old sealant has to come out completely.
What does external mastic cost?
It depends on the job, so we quote each one individually. To get one, call 0345 464 0079 or send us an email and tell us what needs doing and where.
When will the joints need doing again?
It depends on the exposure, the movement and the product. Treat it as a maintenance item and look at it yearly and reseal when it splits.
What happens on the day
When we get to you, we compare the joints with what we discussed. If anything is different, we explain it before carrying on. Most jobs then take a few hours for a handful of joints, longer for a whole elevation. In a smaller place like Crawley Down, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- We inspect the joints and agree which need resealing and how they’ll be reached.
- Old sealant and any debris are cut and raked out.
- We clean both faces of the joint and prime them where the product calls for it.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- On commercial sites, let us know about site rules
- Mention if the joints have been sealed before
Getting a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints.
Related advice
What happens if it’s left?
Sealing over the top of old mastic does not hold for long. New sealant doesn’t bond well to old, weathered sealant, so the old joint is cut out fully first. In a smaller place like Crawley Down, wherever a wall is exposed, a failed outside joint is a real source of damp. Inside, a split seal lets water into floors and panels just as it would anywhere.
No two jobs are quite the same, so each one gets its own quote. The number of joints, how easy they are to reach and the sealant needed all make a difference, and we will explain the quote if you ask.
What you get with us
- We never seal over old sealant
- More than 20 years in sealant work
- 12-month guarantee on every job
- Experience in homes, commercial sites and hotels
Quotes for external mastic in Crawley Down
We don’t publish a price list, because no two jobs are the same. The quote depends on:
- The old material and how stubborn it is
- The product the joint needs
- Mould in or behind the old joints
- The size of the job
Combining jobs into one visit is normally more efficient than separate visits, so tell us about everything that needs sealing. We’ll give you a clear quote for the lot.
What to tell us for a quote
There’s no need for technical detail. It helps if you can tell us:
- Pictures of the joints, sent by email
- Access, such as stairs, a lift or height
- The rough size of the job
- Whether it has been sealed before
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, ring 0345 464 0079 or drop us an email.
Honest limits
A few problems are outside what sealant work can do:
- Cracked brickwork or render that needs a builder or plasterer
- Structural movement, which needs a surveyor or engineer
- Render that’s blown, hollow or coming away
If in doubt, phone 0345 464 0079 or drop us an email and we will say what we think.
Joints and surfaces we work on
- Brickwork movement joints
- Render & cladding joints
- Concrete & block
- Joints between brick and frames
- Façade panels
- Copings & trims
Keeping the joints in good condition
No joint lasts for ever, but care makes a real difference. A few tips:
- Never let anyone fill a movement joint with mortar
- Fix overflowing gutters above sealed joints
- Keep high-pressure jets off the joints
- Show decorators and builders where the movement joints are
Keep pressure washers away from the sealant. A strong jet can damage the edges of the bead and let water in behind.
A joint that has stopped moving pushes the movement elsewhere, generally as cracking in the brickwork or render nearby. Resealing it early helps prevent that.