Hampshire · England
Bishop's Waltham External Mastic
Sealing brickwork movement joints, render, cladding and façade joints for homes and businesses in Bishop's Waltham and across Hampshire. Fully insured, ARBOMaster approved and guaranteed for a year.
- Sealant pulling away from one side of the joint
- Joints with sealant missing in places
- Failed seals between different materials
External mastic for homes and businesses in Bishop's Waltham
Joints in render and cladding are easy to overlook until a damp patch appears. We inspect them, agree which need doing and reseal with a weatherproof, flexible sealant. Typical jobs include joints with sealant missing in places and sealant that has lost its bond to the brick or render, across concrete & block, brickwork movement joints and copings & trims.
Around Bishop's Waltham, garages, outbuildings and extensions all add to the joints on the outside of a home. Gutter ends, garage door frames and the joints where an extension meets the house are typical spots for leaks.
We stand behind the work with a one-year guarantee.
- Where
- Bishop's Waltham (SO32)
- Wider area
- Hampshire
- Cover
- 12 months on all our work
- Price
- A clear price before work begins
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
What the job involves on each surface
Joints between dissimilar materials
Different materials may need different primers. Both surfaces are cleaned and primed as the product requires.
Render joints
The face of render can be soft, so a low-modulus sealant is kinder to the joint edges. We prime where the product needs it.
Looking after it afterwards
Once the sealant has cured, a few habits help it last:
- Point out the joints to other trades
- Never let anyone fill a movement joint with mortar
- Do not let climbing plants root in the sealant
- Wash walls gently around the sealant
Have a quick look at the joints each spring. Watch for splits, edges coming away or growth in the joint.
If you can see gaps, plants or bare sections in a joint, have it checked. Early work is quicker and leaves a better finish.
When something else is needed
A few problems are outside what sealant work can do:
- Cracks in the bricks or render themselves, away from the joints
- 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 will say what we think before you book.
What we seal
- Façade panels
- Render & cladding joints
- Concrete & block
- Brickwork movement joints
- Copings & trims
- Joints between brick and frames
Work for landlords, hotels and businesses
A neglected joint can let water reach the structure, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
What affects the cost of external mastic
Some jobs are bigger than they look, and some smaller. What affects the quote:
- Which sealant suits the joint
- Working hours on commercial sites
- The size of the job
- Access and height
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
Helping us quote
When you call or email, it’s useful to know:
- Any access issues, like height or stairs
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that’s easy
- How many joints, rooms or windows are involved
There’s no standard price list. Instead, we give you a clear quote for your job. To arrange one, phone 0345 464 0079 or send us an email.
What we do, step by step
Good joint work is mostly preparation, so that’s where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes a few hours to a few days, depending on the length of joint and the access. Parking around Bishop's Waltham is usually easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- First we look over the joints with you, agree which to renew and talk through access.
- 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.
- Closed-cell backing rod is fitted to set the depth and stop three-sided bonding.
- A flexible exterior sealant is applied and tooled in a colour to suit the wall.
Getting ready for the visit
- Tell us about any water getting in
- Keep children and pets away from the work area
- On commercial sites, let us know about site rules
Get a quote
We quote each job on its own, so the first step is telling us about yours. Simply phone 0345 464 0079 or email us and describe the job, and photos are welcome.
Read more
Bishop's Waltham 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.
If you let a flat or house near Botley station, split movement joints are easy to miss on a rental until damp shows inside. For site and facilities teams at buildings such as Bishop's Waltham Junior School, larger buildings have long runs of movement joint that eventually need resealing. In the older streets around Church of St Peter, an extension built onto an older house moves differently, and the joint between them takes the strain.
Bishop's Waltham is about 5 miles north-east of Hedge End, in Hampshire. Homes, rented property, offices and hotels in Bishop's Waltham is covered for external mastic, old or new, large or small. The work is guaranteed for a year. Bishop's Waltham is one of 683 towns and villages in Hampshire we cover. We also work in Southampton, about 8 miles from Bishop's Waltham.
Every address in SO32 is within our area for external mastic, from the main roads to the quietest streets. You’ll find streets such as High Street, St Georges's Square and Station Road, and we cover them all. With the B2177 and B3035 close by, Bishop's Waltham is simple for us to get to. We also cover the places around Bishop's Waltham: Ashton (1 mile north), Waltham Chase (2 miles south), Durley Street (2 miles west), Wintershill (2 miles west) and Upham (2 miles north-west). We also work in nearby towns such as Winchester (8 miles north-west), Gosport (11 miles south), Havant (12 miles south-east), Eastleigh (6 miles west), Fareham (7 miles south) and Horndean (9 miles east).
Landmarks near Bishop's Waltham
In Bishop's Waltham, that means homes and buildings near Swanmore College of Technology and The Crown Hotel and the streets around them. The nearest railway station is Botley station, about 3.3 miles south-west. Other landmarks nearby include Bishop's Waltham Museum (within half a mile south-west) and Moorgreen Hospital (5.1 miles west). The countryside around Bishop's Waltham includes Bishops Waltham Branch LNR and Beacon Hill.
Nearby places to Bishop's Waltham
What else we do in Bishop's Waltham
Why it’s worth doing now in Bishop's Waltham
Mortar or ordinary filler might look like a quick way to close an open joint, but it stops the joint moving. The movement then cracks the brickwork or render nearby. The correct repair is a flexible sealant with the right backing. In a smaller place like Bishop's Waltham, wherever a wall is exposed, a failed outside joint is a real source of damp. Indoors, a failed seal lets water into floors and panels as it would anywhere.
Combining jobs into one visit generally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Why Bishop's Waltham customers choose us
- An ARBOMaster approved applicator
- Sanitary silicone with an anti-fungal additive in wet areas
- We agree the colour with you first
- Quality sealants from Arbo and Everbuild
Bishop's Waltham: your questions answered
Do you cover Bishop's Waltham for external mastic?
Yes, Bishop's Waltham is within the area we cover. We work across London and the South East. Just phone 0345 464 0079 or drop us an email with a few details of the job, and we will give you a clear price.
I let a flat near Botley station. Can you help?
Yes, we work for landlords and letting agents. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Do you use backing rod?
That’s backing rod, a closed-cell foam. It keeps the sealant at the right depth and bonded to the sides only.
How do I get a quote for external mastic in Bishop's Waltham?
Size, access and the old material all affect the cost. Ask us for a quote.
What is a movement joint?
It’s a deliberate gap that lets the wall expand and contract without cracking. It should be filled with flexible sealant, never mortar.
Can new sealant go over the old?
No, because it fails. The old sealant always comes out first.
Where are you based?
Our base is Crawley. Our area covers South East England, London and Scotland.
Can I do it myself?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.