West Sussex · England
The Haven External Mastic
External mastic in The Haven from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Movement joints with cracked, split or missing sealant
- Gaps where render, brick and frames meet
- Sealant that has lost its bond to the brick or render
Common questions in The Haven
Can you do external mastic in The Haven?
Yes, The Haven is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or email us with a few details of the job, and we will give you a clear quote.
Do you work for landlords with property near Billingshurst station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Do you work at height?
That depends on the building and the joints. Where joints can be reached safely, we’ll do them. Tell us about the building and we will confirm what access is needed.
Do you have insurance?
Yes. We are fully insured.
What should I tell you?
Let us know what needs doing and where, plus photos if you have them. We’ll ask anything else we need to know.
How long does external mastic last?
That varies with the weather the wall faces, how much it moves and the sealant used. Treat it as a maintenance item and look at it yearly and reseal when it splits.
Should I point up the gap in my brickwork?
No. Rigid materials can’t move with the wall and the joint fails. Where a joint has been mortared, it can often be raked out and sealed properly.
What is backing rod for?
Closed-cell backing rod sets the depth of the sealant and stops it sticking to the back of the joint. Then the sealant bonds to two faces and can move.
External mastic in The Haven, done properly
Where two different materials meet, such as brick and render or blockwork and metal, they move at different rates. A flexible sealant bridges the two. We’re often asked to deal with old sealant gone brittle and cracked and movement joints with cracked, split or missing sealant, across render & cladding joints, concrete & block and façade panels.
Somewhere as small as The Haven, homes and farm buildings often face open ground, where walls and rooflines take the weather head on. Gutter joints and wall joints there need a sealant that can flex and stay put.
Whatever the size of the job, you get the same one-year guarantee.
- Where
- The Haven (RH14)
- Region
- West Sussex
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Updated
- 26 October 2026
How the visit works
We keep the work tidy and contained to the joints we’re treating. The job normally takes a few hours to a few days, depending on the length of joint and the access, and we tell you how long to leave it before we go. Somewhere as small as The Haven, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First we look over the joints with you, agree which to renew and talk through access.
- The old mastic and anything lodged in the joint is removed.
- Both sides are cleaned back to sound material and primed if needed.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- Tell us about any water getting in
- Plan for the work area to be out of bounds to pets and children
Get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we’ll talk you through what we’d do. Whenever you are ready, call 0345 464 0079 or email us.
Related advice
What affects the quote in The Haven
We quote each job individually. These are the things that affect it:
- How easy the joints are to reach
- How much old sealant there is and how hard it is to remove
- The product the joint needs
- The size of the job
Leaving a failed joint normally makes the job bigger, not smaller. If you’re not sure whether it needs doing, ring 0345 464 0079 or email us for an honest opinion and a quote.
What we need to know
When you call or email, it’s useful to know:
- What’s wrong with the joints now
- If it’s domestic, commercial or a hotel
- How many joints, rooms or windows are involved
- How we’d reach the joints
For a quick quote, get us on the phone, or send an email if you’d rather. Tell us about the joints that need doing and we’ll explain what’s involved.
Leave it or put it right?
An open joint keeps letting water into the wall with every downpour. Wet masonry is more easily damaged by frost around the joint, so the damage spreads beyond the joint. Older cottages and farmhouses around The Haven can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
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 play a part, and we will explain the quote if you ask.
Why choose Mr Mastic in The Haven
- 12-month guarantee on every job
- Fully insured
- Colour agreed with you before any work starts
- Tidy, careful work
Towns and villages near The Haven
Also in The Haven
DIY sealant or a professional job?
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
How to look after the new joints
Aftercare is simple:
- Keep movement joints as flexible joints, not mortar
- Deal with leaking gutters that soak the joints below
- Act on the first splits you see
- Look over the joints every year, ideally after winter
Don’t let soil, plants or ivy build up against the new joints. Damp material against the sealant shortens its life.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established, so it’s worth resealing at the first signs.
The Haven buildings and the weather
Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
Rented homes near Billingshurst station change hands often, and failed wall and movement joints let damp in, so they’re worth checking between tenancies. In and around The Haven, as anywhere, good external mastic starts with a clean, dry, properly prepared joint.
The Haven is about 3 miles north of Billingshurst, in West Sussex. If you need external mastic in The Haven, it’s easy to get a quote: please call 0345 464 0079 or email us. We cover West Sussex from our Crawley base. Across West Sussex, we cover 371 places, The Haven among them. We also work in Crawley, about 12 miles from The Haven.
Every address in RH14 is covered for external mastic, from the main roads to the quietest streets. Other places close to The Haven include Five Oaks (1 mile south-east), Bucks Green (2 miles north), Slinfold (2 miles east), Rudgwick (2 miles north) and Tisman's Common (2 miles north-west). We also work in nearby towns such as Crawley (12 miles east), Horsham (5 miles east), Broadfield (11 miles east), Storrington (10 miles south), Billingshurst (3 miles south) and Bewbush (10 miles east).
What’s near The Haven
We work in homes and buildings around The Blue Ship Public House. For rail, the closest station is Billingshurst station, about 3.4 miles south. Well-known places in the area include Horsham Hospital (5.3 miles east) and Christs Hospital School Museum (3.9 miles east).
How the job changes by surface
Brickwork movement joints
Brick moves with heat and moisture, and grows a little over time. The movement joint takes that up, so its sealant has to stay flexible.
Copings and trims
Copings expand and contract through the day, so the joints need a sealant that stays flexible.
Landlords, agents and businesses in The Haven
For anyone letting property in or around The Haven, several properties can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
Whether it’s one flat or a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.