Hampshire · England
External Mastic in Selborne
Professional external mastic in and around Selborne, with old sealant always removed completely and a 12-month guarantee.
- Weathered mastic that no longer stretches
- Weeds or debris growing in open joints
- Damp patches traced to an open external joint
External mastic in Selborne
Getting the depth right is half the job. Backing rod controls how deep the sealant goes and keeps it off the back of the joint, so it bonds to the two sides only and can stretch. Typical jobs include leaking joints around cladding and façade panels and weathered mastic that no longer stretches, across concrete & block, copings & trims and joints between brick and frames.
External sealant needs dry, clean surfaces, so work around Selborne is planned for dry weather. Let us know about access to every wall, plus any garages or outbuildings.
Our work is backed for twelve months, in Selborne and everywhere else we cover.
- Place
- Selborne (GU34)
- Wider area
- Hampshire
- Cover
- One year on every job
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Walls and rooflines in Selborne
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 look after a building such as Selborne Church of England Primary School, its movement joints, gutters and trims need looking after like any other building’s. For landlords with property near Alton station, split movement joints are easy to miss on a rental until damp shows inside. Homes close to Church of St Mary include some older properties, and an extension built onto an older house moves differently, and the joint between them takes the strain.
Selborne is about 4 miles south of Alton, in Hampshire. For external mastic in and around Selborne, it’s easy to get a quote: please phone 0345 464 0079 or email us. We cover Hampshire from our Crawley base, Selborne included. Our area takes in 683 places across Hampshire, large and small. Our Portsmouth page covers work nearby.
All of GU34 is within our area for external mastic. We cover properties on Huckers Lane, Ganders Close and Selborne Road. We also cover the places around Selborne: Newton Valence (1 mile west), Empshott (2 miles south-east), Lower Green (3 miles south), Hawkley (3 miles south) and Oakshott (4 miles south). Within a short drive, we also cover Basingstoke (13 miles north-west), Fleet (13 miles north), Horndean (14 miles south), Aldershot (13 miles north-east), Alton (4 miles north) and Waterlooville (15 miles south).
Near you in Selborne
Locally, jobs take us to homes and businesses close to The Jubilee Tap, among other places. The nearest railway station is Alton station, about 3.8 miles north of the centre. Other landmarks nearby include The Romany Museum (within half a mile south-east) and Alton Community Hospital (3.5 miles north-west). Green spaces nearby include Selborne Hill and Deadwater Valley.
How to look after the new joints
Joint life depends on how it’s used and looked after. Here’s what we suggest:
- Never let anyone fill a movement joint with mortar
- Have failed joints looked at early
- Show decorators and builders where the movement joints are
- Check external joints each spring
Give the sealant the cure time we tell you before anything rubs against it. The surface skins over quickly, but full cure takes longer.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established so early resealing is worth it.
Landlords, agents and businesses in Selborne
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. We can quote for more than one property at once.
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a one-year guarantee.
How we quote for external mastic
Jobs vary more than people expect. What affects the quote:
- How easy the joints are to reach
- How many areas need sealing
- Whether old sealant or filler has to be cut out
- Working hours on commercial sites
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
Asking for a quote
Photos help, but a description is a good start. Try to tell us:
- Any previous sealing or DIY work
- What’s wrong with the joints now
- Photos by email, if that is easy
- Whether it’s a home or a business
For external mastic in Selborne, call 0345 464 0079 or send us an email. A short description of the job and where it is helps us quote, and we’ll agree the price before any work begins.
Nearby places to Selborne
Other services in Selborne
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
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
Where a cladding system has its own specified sealant, we follow it. Send us any details you have about the façade.
Concrete and blockwork
Concrete and block walls shrink as they dry and move with temperature. Their movement joints are sealed over backing rod with a flexible sealant.
Why it’s worth doing now in Selborne
Water gets in through a failed movement joint. Resealing early keeps the job to the joint itself, rather than the wall around it. Where a wall is exposed, as many are in small places like Selborne, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
What it costs depends on the amount of work, how hard the old material is to remove and access to the work. You’ll have a clear quote before any work starts.
Why Selborne clients choose us
- A choice of colours where the product allows
- We agree the colour with you first
- One-year guarantee on every job
- Neat joints and a tidy finish
How the visit works
When we arrive, we start by going over the job with you. We protect the surfaces around the joints before work begins. Most jobs take anything from a few hours to several days, depending on the building. In a small place like Selborne, access is normally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We look at every joint and agree a colour to suit the wall.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- A low-modulus exterior sealant is gunned in and tooled to a neat finish.
Getting ready for the visit
- Let us know about earlier repairs to the joints
- For business premises, tell us about site rules or sign-in
- Clear the area around the work
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email photos if that’s easy.
Related advice
Your questions about external mastic in Selborne
Can you do external mastic in Selborne?
Yes, Selborne is within the area we cover. Our work covers London and the South East. You can phone 0345 464 0079 or email us and let us know what needs doing, and we will send you a clear quote.
Do you work for landlords with property near Alton station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we’ll send you a clear quote.
How long does external mastic take?
Typically it takes anything from a few hours to several days, depending on the building. Larger jobs naturally take longer, and we’ll tell you how long to expect.
Can you reach joints on upper floors?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we’ll confirm what’s needed.
Should I try DIY first?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
How long before the joint can be used?
Most sealants are touch-dry well before they’re fully cured. We’ll tell you how long to leave the joint.
What do you put in the joint?
Each joint gets the product that suits it. Movement, water and weather all affect the choice, and we will explain our choice.
Will you leave a mess?
No. We protect the surfaces around the joints, and we tidy up before we go.