Hampshire · England
External & façade joints in St Leonards, Hampshire
External mastic for St Leonards, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Hard, crazed mastic that has stopped moving
- Water getting into walls through failed joints
- Movement joints with cracked, split or missing sealant
External mastic for homes and businesses in St Leonards
Ground-floor and low-level joints are straightforward to reach. For joints higher up, give us some details of the building and we’ll confirm what access is needed. If you are dealing with rigid filler in a joint that should flex and rain getting behind render or cladding at a joint, we can help, whatever the surface.
Homes around St Leonards range from older cottages to newer houses, with walls and rooflines of every type. Older gutters and trims need their joints resealed; newer brick and render need their movement joints kept sound.
Your job is guaranteed for a year, as with all our work.
- Place
- St Leonards (BH24)
- Region
- Hampshire
- Cover
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
How we quote for external mastic
For a quick quote, just ask. The main things that affect it are:
- Which sealant suits the joint
- Access and height
- The amount of work
- Whether there’s mould to deal with
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
What to tell us for a quote
The more you tell us, the more accurate the quote. When you ask for a quote, tell us:
- Where the property is
- A few photos by email, if you can
- The problem you’ve noticed
- The rough size of the job
There’s no standard price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To get started, call 0345 464 0079 or send us an email.
DIY sealant or a professional job?
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 doesn’t work out, we can still put it right.
A careful DIYer can reseal a simple joint, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
How the job changes by surface
Cladding and façade panels
Cladding and façade panels are usually separated by sealed joints. We reseal them with a sealant suited to the panel material.
Joints between dissimilar materials
Joints where frames, sills or panels meet the wall are common leak points. We cut out the old sealant and reseal with a product suited to both surfaces.
Common questions in St Leonards
Is external mastic in St Leonards guaranteed?
All our work, in St Leonards and everywhere else, comes with a 12-month guarantee. We are fully insured, and an ARBOMaster approved applicator.
Will you come out to St Leonards?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Do you work at height?
It depends on the building. Tell us the height, the number of joints and what’s below them and we’ll confirm how they can be reached safely.
Are you fully insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Can you do several jobs on one visit?
Yes. Tell us about everything you’d like done and we will quote it together.
Can tenants book the work?
Yes. Ask your landlord first, and we can send them the quote if that helps.
What do you put in the joint?
Products from Arbo and Everbuild, among others, picked for each joint. We explain the product when we quote.
What colours does the sealant come in?
We aim for a joint that suits the wall rather than one that jumps out. We’ll talk through colour options before any work starts.
Walls and rooflines in St Leonards
Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you live in an older home near All Saints, old and new materials meet at the roofline and walls, which is where sealant earns its keep.
St Leonards is in Hampshire. St Leonards gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Our Hampshire coverage runs to 683 places, and St Leonards is one of them. There’s also a page for Southampton, roughly 21 miles from St Leonards.
Every address in BH24 is covered for external mastic, from the main roads to the quietest streets. Whether your property is on Cedar Avenue, Birch Close and Malmesbury Road or anywhere close by, our applicators can take on the job. If you’re just outside St Leonards, we cover Ashley Heath (1 mile north), St Ives (1 mile north-east), Matchams (1 mile south-east) and Avon Castle (2 miles east). Larger places within reach include Lymington (14 miles east), New Milton (10 miles south-east), Ringwood (3 miles north-east), Barton on Sea (10 miles south-east), Ashley (10 miles south-east) and Milford on Sea (13 miles south-east).
Near you in St Leonards
Typical jobs here are in homes near Avon Heath Country Park. A little further out are St Leonard's Hospital (0.9 miles south-west) and Stapehill Abbey (3.9 miles south-west). Open spaces near St Leonards include Linbrook Lake and Blashford Lakes.
Why deal with it now?
It often makes sense to reseal all the failing joints on an elevation together. Joints of the same age tend to fail together, and access only has to be arranged once. In a smaller place like St Leonards, 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.
A failed joint rarely gets cheaper to fix by waiting. If you’re unsure, call 0345 464 0079 or email us for an honest opinion and a quote.
Why St Leonards customers choose us
- Anti-fungal silicone where joints get wet
- 20+ years of sealant experience
- Experience in homes, commercial sites and hotels
- We agree the colour with you first
How to look after the new joints
After the cure time, these simple habits help:
- Deal with leaking gutters that soak the joints below
- Show decorators and builders where the movement joints are
- Walk round the building once a year and look at the joints
- Check the sealant is paintable before painting near it
Do not let soil, plants or ivy build up against the new joints. Anything that holds water against the joint wears it out sooner.
Small splits are the time to act. At that stage it’s a simple cut out and reseal before water has had years to get in.
Also near St Leonards
Other services in St Leonards
The process
The work is kept neat and contained to the area we’re working on. Expect the work to take a few hours for a handful of joints, longer for a whole elevation, and we tell you how long to leave it before we go. For a job in St Leonards, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- Each joint is checked and the colour of the new sealant agreed.
- Failed sealant is removed back to clean, sound faces.
- Closed-cell backing rod is pushed in so the sealant bonds to two sides only.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Before we arrive
- Mention any tricky access
- Mention any sign-in or site rules at work premises
- Try not to wet indoor joints just before the visit
Get a quote
Getting a quote is simple: let us know the job and the location. A few photos by email make the job easier to understand, and we will take it from there.
Read more
What we’re called out for in St Leonards
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it can’t stretch and tears as soon as the joint widens.
Signs it’s time to call us include:
- Sealant pulling away from one side of the joint
- Rigid filler in a joint that should flex
- Brick movement joints where the sealant has split
- Weeds or debris growing in open joints
For site and facilities teams at buildings such as St Ives Primary & Nursery School, movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
What to look for in a quote
- Who turns up on the day
- Whether VAT is included
- Whether you can choose the colour
- What preparation is included