Hampshire · England
Ossemsley External Mastic
Professional external mastic in and around Ossemsley, with old sealant always removed completely and a 12-month guarantee.
- Hard, crazed mastic that has stopped moving
- Sealant that has lost its bond to the brick or render
- Water getting into walls through failed joints
How we handle external mastic in Ossemsley
As ARBOMaster approved applicators, we choose exterior sealants to suit the joint and the surfaces. Porous or awkward surfaces are primed where the sealant needs it and we use one wherever it does. Typical jobs include sealant that has lost its bond to the brick or render and movement joints filled with mortar instead of sealant, on render & cladding joints, copings & trims and concrete & block.
External sealant needs dry, clean surfaces, so work around Ossemsley is planned for dry weather. Let us know about access to every wall, plus any garages or outbuildings.
All our work comes with a 12-month guarantee.
- Location
- Ossemsley (BH25)
- Wider area
- Hampshire
- Guarantee
- 12 months on all our work
- Price
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Ossemsley buildings and the weather
Ossemsley is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. 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.
In the older streets around St John, the joints between older walls, newer extensions and the roofline need a sealant that can move. Managing a site like Ballard School? Then its movement joints, gutters and trims need looking after like any other building’s.
Ossemsley is about 2 miles north of New Milton, in Hampshire. Across the BH25 area, we cover external mastic for homes and businesses. Ossemsley is one of 683 places in Hampshire we cover. Our Southampton page covers work nearby.
Postcode districts we cover here for external mastic: BH25. We cover properties on Green Lane and Ossemsley South Drive. We also cover the places around Ossemsley: Bashley (1 mile south-east), Wootton (1 mile north), Tiptoe (2 miles east), Mead End (2 miles east) and Ashley (2 miles south-east). We also work in nearby towns such as Totton (12 miles north-east), Lymington (5 miles east), Hythe (13 miles north-east), Ringwood (7 miles north-west), Barton on Sea (3 miles south) and Dibden Purlieu (12 miles north-east).
What’s near Ossemsley
Around Ossemsley, our work takes us to homes and buildings near The Arnewood School and The Rising Sun pub. The closest station to Ossemsley is New Milton station, about 1.7 miles south of the centre. Nearby you will also find Highcliffe Castle (3.5 miles south-west) and Sammy Miller Motorcycle Museum (1 mile south). Open spaces near Ossemsley include Milford on Sea LNR.
For landlords and businesses
We work for landlords and letting agents as well as homeowners. Sealant work between tenants keeps a property looking cared for.
Housing providers, facilities teams and property managers book us too. Several sites can go on one quote, and we are fully insured.
Can I do it myself?
A DIY attempt does not rule out a professional job. We cut it out and start again, so just mention it when you contact us.
Sealing over old silicone is the commonest DIY error. New silicone will not bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
How the job changes by surface
Cladding and façade panels
Cladding and façade panels are normally separated by sealed joints. We reseal them with a sealant suited to the panel material.
Concrete and blockwork
Blockwork and concrete shrink over time and move with the seasons. We reseal their joints with backing rod and a flexible product.
Honest limits
It helps to know what we can’t do too:
- Cracked brickwork or render that needs a builder or plasterer
- Loose or hollow render, which needs re-rendering
- Adding movement joints to masonry that has none
If in doubt, call 0345 464 0079 or email us and we’ll say what we think before you book.
Joints and surfaces we work on
- Render & cladding joints
- Brickwork movement joints
- Concrete & block
- Copings & trims
- Joints between brick and frames
- Façade panels
Also in Ossemsley
How to look after the new joints
Looking after new joints is easy, and it makes a real difference:
- Deal with leaking gutters that soak the joints below
- Leave the joints unpainted unless we’ve said otherwise
- Keep soil, plants and ivy away from the joints
- Show decorators and builders where the movement joints are
Give the sealant the cure time we tell you before anything rubs against it. Most exterior sealants skin fast but take longer to cure right through.
Leave a failed movement joint and water keeps getting into the wall. That can lead to damp patches, staining and frost damage which cost more to put right than the joint.
Signs you need external mastic in Ossemsley
Joints sealed without backing rod, or far too deep, rarely last. If the sealant sticks to the back as well as the sides, it cannot stretch and tears as soon as the joint widens.
It’s worth asking for a quote if you see:
- Joints where the bead has come unstuck
- Old sealant gone brittle and cracked
- Leaking joints around cladding and façade panels
- Rigid filler in a joint that should flex
If you let a flat or house near New Milton station, split movement joints are easy to miss on a rental until damp shows inside.
Comparing quotes
- What happens if they find a problem under the old sealant
- Whether the sealant suits the joint
- What the quote includes, VAT included or not
- Is the old sealant removed completely?
What happens on the day
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, carry out the job and clear up. It usually takes anything from a few hours to several days, depending on the building. Somewhere as small as Ossemsley, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- 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.
- We gun in a flexible exterior sealant in a colour that suits the wall and tool it neatly.
Preparing for the visit
- For indoor joints, keep the area dry beforehand if you can
- Mention if the joints have been sealed before
- Let us know about stairs, lifts or work at height
Getting a quote
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 will explain what’s involved and give you a clear price.
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Questions from Ossemsley
Do you cover smaller places like Ossemsley?
Yes, we do. Our work covers London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Does living near the coast affect external mastic in Ossemsley?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
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.
Will you leave a mess?
No. We work neatly, protect the area around the joints and tidy up afterwards.
Do you have insurance?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Do you use backing rod?
The foam is closed-cell backing rod. It keeps the sealant at the right depth and bonded to the sides only so it can flex with the joint.
How long does the job take?
That depends on how much there is to do, but most jobs take a few hours to a few days, depending on the length of joint and the access. We will give you a better idea when we quote.
Should I point up the gap in my brickwork?
No. Rigid materials can’t move with the wall and the joint fails. If it has already been filled, we can usually cut it out and reseal it.