Hampshire · England
Lockerley External Mastic
External mastic for Lockerley and the surrounding area: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Old sealant gone brittle and cracked
- Panel joints letting water in
- Movement joints filled with mortar instead of sealant
External mastic in Lockerley
A movement joint is only as good as its depth. Closed-cell backing rod sets the depth and stops the sealant sticking to the back, so it bonds to the two sides only and can stretch. If you’re dealing with joints pointed up with cement by mistake and movement joints with cracked, split or missing sealant, we can help, whatever the surface.
Outside joints can only be sealed when they’re dry, so work in Lockerley is booked around the forecast. Tell us about access to all sides of the building, including outbuildings and garages.
Our work is backed for twelve months, in Lockerley and everywhere else we cover.
- Where
- Lockerley (SO51)
- Wider area
- Hampshire
- Cover
- 12 months on all our work
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
How the job changes by surface
Render joints
Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.
Concrete and blockwork
Big joints in concrete need careful depth control. Backing rod sized to the joint sets it so the sealant isn’t too deep.
When to call us in Lockerley
Many joints fail because they were sealed too deep or with nothing behind them. If the sealant sticks to the back as well as the sides, it cannot stretch and tears as soon as the joint widens.
Look out for any of the following:
- Sealant pulling away from one side of the joint
- Movement joints filled with mortar instead of sealant
- Damp patches traced to an open external joint
- Movement joints with cracked, split or missing sealant
Schools such as Lockerley Church of England Endowed Primary School are buildings too, and movement joints, cladding joints and gutters on larger buildings need the same care as a house’s.
Questions to ask before booking
- Is the old sealant removed completely?
- How the joint is cleaned and prepared
- How the colour is chosen
- How long the guarantee is
Why deal with it now?
Sealing over the top of old mastic doesn’t hold for long. The new layer cannot bond properly to old, weathered material, so we always take the old sealant out. In a small place like Lockerley, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part.
Why Lockerley clients choose us
- Arbo and Everbuild products
- We are fully insured
- Colour picked to suit the job
- Every job guaranteed for a year
Take a look at our cost guide or customer reviews.
DIY versus a professional finish
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, then guaranteed for a year.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
What we cannot put right
Before you book, it’s worth knowing the limits:
- Cutting new joints into brickwork, which is building work rather than sealant work
- Subsidence or other structural problems
- Cracking across the wall rather than at a joint
Not sure which it is? You can ring 0345 464 0079 or send us an email and we will tell you honestly.
Joints and surfaces we work on
- Render & cladding joints
- Copings & trims
- Joints between brick and frames
- Façade panels
- Brickwork movement joints
- Concrete & block
Also near Lockerley
Other services in Lockerley
Looking after it afterwards
No joint lasts for ever, but care makes a real difference. Our tips:
- Tell anyone working on the walls about the movement joints
- Check external joints each spring
- Get split or bare joints resealed while the damage is small
- Clear growth from the base of walls and joints
Keep pressure washers away from the sealant. High-pressure water can lift the edges 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.
How the visit works
On the day, there’s very little for you to do. Point us to the joints and we will get on with it. The work itself takes a few hours to a few days, depending on the length of joint and the access from start to finish. In a small place like Lockerley, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- The faces are brushed clean and primed where the product requires it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Getting ready for the visit
- Move anything stored near the joints
- Let us know about earlier repairs to the joints
- Mention any tricky access
How to get a quote
We do not publish a price list. Instead, we give you a clear quote for your job. To arrange one, ring 0345 464 0079 or send us an email.
Related advice
Outside joints around Lockerley
Historic houses like Mottisfont Abbey (about 1.8 miles east) are a reminder that the area around Lockerley has older buildings as well as new. In older buildings, 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.
In the older streets around Church of St John, old and new materials meet at the roofline and walls, which is where sealant earns its keep. Rented homes near Mottisfont & Dunbridge station change hands often, and split movement joints are easy to miss on a rental until damp shows inside.
Lockerley is about 5 miles north-west of Romsey, in Hampshire. Every kind of property in Lockerley can book us for external mastic. The work is guaranteed for a year. 683 places in Hampshire are on our list, from the larger towns to small villages. There’s also a page for Southampton, about 11 miles away.
Jobs for external mastic in SO51 works the same way as everywhere else we cover. If you need external mastic at a property on Butlers Close, Oval Road and Clem's Way or a nearby road, we can help. If you’re just outside Lockerley, we cover Carter's Clay (1 mile south-east), Dunbridge (1 mile east), Mottisfont (2 miles east), Kimbridge (2 miles east) and Awbridge (2 miles south-east). Larger places within reach include Winchester (11 miles east), Eastleigh (11 miles south-east), Andover (13 miles north), Totton (8 miles south), Chandler's Ford (9 miles east) and Hedge End (14 miles south-east).
What’s near Lockerley
Around Lockerley, our work takes us to homes and buildings near Kings Arms Public House, among other places. The nearest railway station is Mottisfont & Dunbridge station, roughly 1.2 miles east. A little further out are Romsey Community Hospital (4.9 miles south-east).
Your questions about external mastic in Lockerley
Do you cover Lockerley for external mastic?
Yes. We work across London and the South East, and Lockerley is part of that. You can ring 0345 464 0079 or email us and tell us what needs doing, and we will give you a clear price.
Is Lockerley within the area you cover?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
Are you an approved applicator?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
Is it OK to seal over old sealant?
No, it will not last. It may look fine at first, but the new bead soon lifts. Removing the old sealant completely is the only lasting way.
Do you have insurance?
Yes. Mr Mastic is fully insured.
Is there any odour?
It depends on the product. Some smell for a while, some hardly at all, and any smell fades as they cure.
What is a movement joint?
A movement joint is a planned break in the wall that absorbs expansion and shrinkage. It should be filled with flexible sealant, never mortar.
Do I have to be there?
That depends on where the joints are. For work indoors, someone needs to let us in, while outside work can sometimes be arranged differently.