Hampshire · England
South Down New Build Mastic
New build mastic for South Down and the surrounding area: careful preparation, the right product and tidy work. Call for a quick quote.
- Untidy sealant flagged on a snagging list
- Plot mastic for developers ahead of handover
- Leaking shower tray seals in a new home
How we handle new build mastic in South Down
If your new home has a leaking shower seal, open skirting joints or untidy sealant, we can help. While the builder’s snagging or warranty period runs, report it to them first and if that stalls, we can do it. We work on show homes, skirting & floors and bathrooms & en suites, and common reasons people get in touch are skirting joints opening in the first winter and untidy sealant flagged on a snagging list.
Older homes in small places like South Down often have timber floors that move with the seasons, which is why skirting and threshold joints need a flexible sealant, not filler.
All our work is covered by a 12-month guarantee, wherever you are in Hampshire.
- Location
- South Down (SO21)
- Wider area
- Hampshire
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Signs you need new build mastic in South Down
The wrong product is sometimes used in the wrong place: decorators’ caulk in a wet area, or a stiff sealant where there’s movement. Both fail early.
These are the problems we are asked about most:
- Kitchen sealant that has pulled off the wall
- Frame joints opening as the plaster dries
- Joints pulling apart as timber shrinks
- Shower seals failing in the first year or two
In and around South Down, as anywhere, good new build mastic starts with a clean, dry, properly prepared joint.
What to look for in a quote
- Whether they seal over old material or remove it
- Who turns up on the day
- How long to leave it before use
- What product goes in the joint
How to look after the new joints
Aftercare is simple, and it makes a real difference:
- Keep water off fresh sealant until it has cured
- Act quickly if a seal starts to leak
- Wipe joints with warm soapy water
- Watch for new gaps as the house dries out
Keep pictures of the joints and any snagging correspondence with your builder. It’s useful if you need to raise other issues later.
Mould takes hold quickly in sealant that has gaps or lifted edges. Dealing with it before it goes black saves a harder job later.
Nearby places to South Down
What else we do in South Down
New homes and floors in South Down
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
If you’ve bought a new home near Shawford station, the sealant around baths, showers and frames is worth checking in the first year or two.
South Down is about 3 miles north-east of Chandler's Ford, in Hampshire. If you need new build mastic in South Down, it’s easy to get a quote: please call 0345 464 0079 or email us. We cover Hampshire from our Crawley base, South Down included. South Down is one of 683 places in Hampshire where we work for new build mastic. For nearby work, see our Southampton page (7 miles or so).
All of SO21 is within our area for new build mastic, from the main roads to the quietest streets. If you need new build mastic at a property on Cross Way, Fairfield Road and Grove Road or anywhere close by, we can help. If you’re just outside South Down, we cover Compton (1 mile north), Otterbourne (1 mile south-west), Shawford (1 mile north-east), Twyford (1 mile east) and Oliver's Battery (2 miles north). We also work in nearby towns such as Winchester (3 miles north), Eastleigh (3 miles south), Fareham (13 miles south-east), Andover (15 miles north-west), Totton (10 miles south-west) and Chandler's Ford (3 miles south-west).
What’s near South Down
We work in homes and buildings around The Bridge Inn and Thornden School. South Down’s nearest station is Shawford station, about 0.6 miles north-east of the centre. Nearby you will also find Balfour Museum of Hampshire Red Cross History (2.9 miles north) and Wolvesey Castle (3.2 miles north). The countryside around South Down includes Twyford Down and Shawford Down.
Landlords, agents and businesses in South Down
From a single let to a portfolio, you get the same standard of work: the old material taken out, careful preparation and a 12-month guarantee.
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we will give you a quote.
Can I do it myself?
If you’ve already had a go yourself, that’s fine. We remove it and do the joint properly.
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
When it is not the sealant
We won’t take on work that will not last, so these are the limits:
- Structural cracks in walls or ceilings
- Baths and trays that move too much for sealant to cope with
- Deciding who is responsible under a builder’s warranty
If you are not sure, just call 0345 464 0079 or send us an email and we will give you a straight answer.
Where we work in South Down
- Kitchens
- Plot handovers
- Show homes
- Bathrooms & en suites
- Windows & doors
- Skirting & floors
South Down questions
Do you cover smaller places like South Down?
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.
Do you work for landlords with property near Shawford station?
Yes, we work for letting agents and landlords. Just ring 0345 464 0079 or drop us an email and tell us about the property, and we will send you a clear quote.
Are you fully insured?
Yes, we’re fully insured for every job we do.
Can you reseal over the builder’s sealant?
No. The old sealant is cut out fully, the joint cleaned and primed where needed, and a new bead applied.
Can I do it myself?
Sometimes. The key is preparation: remove all the old material and work on a clean, dry joint. We can always put it right if it fails.
When is the best time to reseal in a new build?
Any seal that is leaking should be redone right away. Cosmetic gaps can wait until the first year or two of movement has passed.
Is it normal for sealant to crack in a new home?
Lots of new homes see sealant crack early. Rushed application on dusty surfaces makes it worse.
Will it make a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
How the visit works
Most of a good job is in the preparation, so that is where we spend the time. Joints are cleaned back and dried before anything new goes in. All told, the work takes anything from a few hours to several days, depending on the number of plots. Somewhere like South Down needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We look at why each joint failed, including any movement.
- Old sealant is cut out and the joints cleaned.
- Joints are dried and primed where the product calls for it.
- New sealant goes in, with baths filled first so they’re at their heaviest.
- The finished joints are checked and the cure times given.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Let us know about stairs, lifts or work at height
- Let us know about parking restrictions
How to get a quote
For a quote, phone 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. You will have a clear quote before any work starts.
Advice
How the job changes by surface
Show homes
Bathrooms, kitchens and frames in show homes are sealed or resealed to a neat finish. Tell us when the home is open so we can plan around it.
Skirting and floors
Where the floor meets a bath panel or kitchen plinth, the joint keeps mop water out. They get a flexible, water-resistant sealant.