Hampshire · England
New-build mastic & snagging in Southwick, Hampshire
Plot mastic for developers and snagging failed sealant in new homes for Southwick, backed by a 12-month guarantee. Ask us for a quote.
- Smeared, uneven beads picked up at snagging
- Shower seals failing in the first year or two
- Kitchen sealant that has pulled off the wall
Questions from Southwick
Can you help a landlord with a rental near Portchester station?
Yes, landlords and agents are among the people we work for, and several properties can go on one quote. Just call 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Do you cover Southwick for new build mastic?
Yes. We work across London and the South East, and Southwick is part of that. You can phone 0345 464 0079 or send us an email and let us know what needs doing, and we will send you a clear quote.
Do you work for hotels and businesses?
Yes. We have worked for hotels, offices and other businesses and we’re fully insured.
Which products do you use?
It depends on the joint: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
Is it normal for sealant to crack in a new home?
It’s common, and there are normally two reasons: the house moving as it dries, and sealant that never bonded properly. Cutting it out and resealing properly fixes both.
Do I have to be there?
That depends on where the joints are. Inside work needs someone to give us access, and for outside work we will agree access with you when we book.
Can new sealant go on top of the old bead?
No. Over-sealing traps mould and water and soon fails. We remove every bit of the old bead before resealing.
Is the work guaranteed?
Yes. Every job comes with our one-year guarantee.
New build mastic for homes and businesses in Southwick
Failed shower seals, gaps along the skirting and messy beads are common items on a new-home snagging list. 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 windows & doors, kitchens and plot handovers, and people most often call us about worktop and upstand sealant coming away and smeared, uneven beads picked up at snagging.
In a village or hamlet like Southwick, new homes are more likely to be a barn conversion or a handful of houses than a big estate. Every one needs its sealant and floor joints done properly, whatever the size of the site.
Every job comes with a 12-month guarantee.
- Place
- Southwick (PO17)
- Wider area
- Hampshire
- Cover
- 12 months on all our work
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Why it’s worth doing now in Southwick
A tube of sealant from the DIY shop won’t fix the cause: grit, unprimed surfaces and old layers underneath. Cutting out, cleaning and priming are what make the difference. Where a wall is exposed, as many are in small places like Southwick, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference, and we’ll explain the quote if you ask.
Why choose Mr Mastic in Southwick
- A sealant colour to suit the surroundings
- We are fully insured
- You choose the colour before work begins
- Homes, businesses and hotels
Read what affects the cost and customer reviews.
How we quote for new build mastic
We don’t publish a price list, because jobs vary so much. The quote depends on:
- The type of sealant required
- Whether there’s mould to deal with
- How much old sealant there is and how hard it is to remove
- When we can work, for business premises
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether the work is at height. Your quote takes all of that into account.
What to tell us for a quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- How we’d reach the joints
- What the problem is, such as mould, gaps, leaks or cracking
- The rough size of the job
- The type of property
Want a quote for new build mastic? Please call 0345 464 0079 or drop us an email and tell us about the job. We’ll explain what we’d do and give you a clear price before any work starts.
Should I try it myself first?
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
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.
How the job changes by surface
Bathrooms and en suites
Shower trays in new homes often move slightly in the first year. The joint is stripped back before the new bead goes in.
Show homes
We seal show-home bathrooms, kitchens and frames to a tidy standard. Tell us when the home is open so we can plan around it.
How it works
Every visit runs the same way: we look at the joints together, mask and protect the surrounding surfaces, do the work and tidy away. Most jobs take a few hours for most snagging lists, longer for a run of plots. In a small place like Southwick, access is generally the main thing to plan. For outside work, also let us know about exposed walls and any outbuildings involved.
- We start by going through the snagging items or plot schedule with you.
- Every bit of the old builder’s sealant is cut out, with no layer left behind.
- We clean out the dust and grit left from the build.
- We prime where needed and apply a sealant suited to each joint.
- Each bead is tooled and the cure times explained.
Getting ready for the visit
- Tell us if parking is tricky
- Keep children and pets away from the work area
- Mention if the joints have been sealed before
Ask for a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will talk you through what we’d do. Whenever you’re ready, call 0345 464 0079 or drop us an email.
Related advice
Nearby places to Southwick
More services for Southwick
New build mastic around Southwick
Southwick is within about 2 miles of the coast. Plot mastic on new homes near the coast takes more weather than it would inland, so it’s worth checking at snagging. 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 and around Southwick, as anywhere, good new build mastic starts with a clean, dry, properly prepared joint.
Southwick is about 3 miles west of Purbrook, in Hampshire. Southwick gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. 683 places in Hampshire are on our list.
All of PO17 is within our area for new build mastic, from the main roads to the quietest streets. New build mastic is available to properties on High Street, North Road West and Castle Road. We also cover the places around Southwick: Boarhunt (1 mile west), North Boarhunt (2 miles north-west), Portchester (2 miles south), Hundred Acres (3 miles north-west) and North Fareham (3 miles west). We also work in nearby towns such as Gosport (5 miles south), Havant (5 miles east), Eastleigh (12 miles north-west), Fareham (4 miles west), Horndean (5 miles north-east) and Chandler's Ford (14 miles north-west).
Around Southwick
In Southwick, that means homes and buildings near Red Lion Inn and the streets around them. For rail, the closest station is Portchester station, about 1.9 miles south of the centre. Other landmarks nearby include Portchester Castle (2.6 miles south) and Fareham Shopping Centre (3.2 miles south-west). For a walk, there’s Portsdown Hill and St Clair's Meadow.
Signs you need new build mastic in Southwick
Later trades and the final clean can damage fresh sealant. If it’s disturbed before curing, the joint can be left weak, and the problem shows up after you move in.
Signs it’s time to call us include:
- Untidy sealant flagged on a snagging list
- Cracked sealant around new window and door frames
- Gaps opening as the house dries out and settles
- Shower seals failing in the first year or two
For new homes near Portchester station, it’s worth checking the sealant early, while snags are still fresh.
What your quote should include
- Whether all the old sealant comes out first
- Is VAT in the price?
- What happens if the job turns out different
- What the cure time is
What we can’t put right
Honest advice matters more to us than a booking, so here’s what new sealant won’t do:
- Plumbing faults behind the sealant
- Damaged fittings that need replacing
- Settlement cracks that need a surveyor
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly before you book.
Surfaces we seal
- Show homes
- Skirting & floors
- Bathrooms & en suites
- Kitchens
- Plot handovers
- Windows & doors