Hampshire · England
New-build mastic & snagging in Haslar, Hampshire
We cover Haslar for plot mastic for developers and snagging failed sealant in new homes. Old sealant removed completely, joints prepared properly and every job guaranteed for a year.
- Internal frame sealant that has split
- Gaps behind new kitchen upstands
- Gaps opening as the house dries out and settles
Can I do it myself?
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so tell us about it when you ask for a quote.
New build mastic for homes and businesses in Haslar
A new house keeps drying out and settling for its first couple of years. Timber shrinks, plaster dries and baths and trays bed down, and sealant applied in a hurry at handover can split. If you have messy sealant that spoils new finishes and new-build shower sealant that has already split, we can put it right, on kitchens, show homes and skirting & floors alike.
In a village or hamlet like Haslar, new homes are more likely to be a barn conversion or a handful of houses than a big estate. Each still needs its sealant and floor joints finished properly.
Our work is backed for twelve months.
- Location
- Haslar (PO12)
- Region
- Hampshire
- Cover
- A year, on every job
- Quotes
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
New build mastic around Haslar
Haslar is close to the coast. New homes near the sea put their outside mastic to work from day one, so any gaps are best picked up early. The South East is one of 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 Portsmouth Harbour station, the sealant around baths, showers and frames is worth checking in the first year or two.
Haslar is about 2 miles south-east of Gosport, in Hampshire. Haslar gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Our area takes in 683 places across Hampshire.
Every address in PO12 is covered for new build mastic. Local streets include Froude Road, Military Road and Monckton Road, all of which we cover. We also cover the places around Haslar: Clayhall (1 mile north-west), Alverstoke (1 mile west), Portsmouth Point (1 mile north-east), Privett (2 miles north-west) and Portsea (2 miles north-east). Larger places within reach include Havant (8 miles north-east), Fareham (6 miles north-west), Horndean (10 miles north-east), Hedge End (12 miles north-west), Waterlooville (8 miles north-east) and Purbrook (7 miles north-east).
Landmarks near Haslar
Around Haslar, our work takes us to homes and buildings near The Fighting Cocks pub, Bay House School and St Vincent College, among other places. Haslar’s nearest station is Portsmouth Harbour station, about 1.5 miles north-east. Well-known places in the area include Tricorn Centre (2.3 miles north-east) and Southsea Castle (1.8 miles east). Not far away are West of the River Alver.
When to call us in Haslar
Baths and trays settle under load once the home is lived in. If a bath wasn’t filled when it was sealed, the bead is stretched the first time it’s used and the sealant may split.
It’s worth asking for a quote if you see:
- Shower seals failing in the first year or two
- Smeared, uneven beads picked up at snagging
- Sealant that never bonded to the surface
- Skirting joints opening in the first winter
Around Haslar, as everywhere, new build mastic is only as good as the preparation behind it.
Comparing quotes
- How long the guarantee is
- Whether all the old sealant comes out first
- Who turns up on the day
- Whether they’re fully insured
Surface by surface
Windows and doors
On new builds, external frame sealant can be patchy. We reseal it with a weatherproof, flexible sealant.
Skirting and floors
Gaps under skirting are one of the most common new-build snags. A flexible sealant closes it without cracking like caulk.
Keeping the joints in good condition
So the new joints stay in good condition:
- Use the extractor fan every time you shower
- Avoid running a DIY bead over the old one
- Look at the sealant regularly in the first couple of years
- Wipe joints with warm soapy water
Leave the sealant for the cure time we give you before showering or bathing. Silicone is generally left for about a day before water reaches them.
Leave a failed new-build seal and water can reach the floor and the ceiling below. Catching it early keeps the fix to the sealant and protects the rest of the house.
Honest limits
To be straight with you, some problems need a different trade:
- Leaks from pipes, valves or wastes, which need a plumber
- Deciding who is responsible under a builder’s warranty
- Settlement cracks that need a surveyor
If you’re not sure, just ring 0345 464 0079 or email us and we’ll give you a straight answer before you book.
Surfaces we seal
- Skirting & floors
- Windows & doors
- Show homes
- Bathrooms & en suites
- Plot handovers
- Kitchens
Towns and villages near Haslar
More services for Haslar
How it works
The work is kept neat and contained to the joints we’re treating, so you can carry on as normal. Expect the work to take a few hours in a single home. Somewhere as small as Haslar, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- We look at why each joint failed, including any movement.
- We remove the failed sealant and clean the joints.
- We make sure the joints are dry and prime them if needed.
- New sealant goes in, with baths filled first so they’re at their heaviest.
- The finished joints are checked and the cure times given.
How to prepare
- Let us know if you’ve seen damp or leaks
- For business premises, tell us about site rules or sign-in
- Clear the area around the work
Get a quote
To get a quote, phone 0345 464 0079 or send us an email with the location and a short description of the problem. We will give you a clear quote before any work starts.
Advice
Common questions in Haslar
I let a flat near Portsmouth Harbour station. Can you help?
Yes. We work for landlords and agents as well as householders. You can call 0345 464 0079 or email us with the details for a clear quote.
Do you cover Haslar for new build mastic?
Yes, Haslar is within the area we cover. We work across London and the South East. You can phone 0345 464 0079 or drop us an email and let us know what needs doing.
Can I add another job to the visit?
Yes. Tell us about everything you’d like done and we will quote it together.
How long does new build mastic take?
Typically it takes anything from a few hours to several days, depending on the number of plots. Bigger jobs take longer, and we’ll tell you how long to expect.
Can you do plot mastic on a new development?
Yes. Plot mastic and second-fix sealing for developers is part of our work. Send us the plot schedule and we’ll quote.
Can I send you my snagging list?
Yes. Send the list and a few photos of the sealant items, and we will quote. We’ll flag anything that needs another trade.
Should I try DIY first?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Do you do commercial work?
Yes. We work in offices, washrooms, hotels and other commercial premises. We can talk about working times when we quote.
Why it’s worth doing now in Haslar
Resealing everything on a snagging list in one visit is usually simpler than chasing joints one at a time. You get one visit and one clear quote for the lot. Older cottages and farmhouses around Haslar can have timber floors and frames, where water from a failed joint can cause rot if it’s left.
Leaving a failed joint generally makes the job bigger, not smaller, as water and mould keep getting in. If you are not sure whether it needs doing, phone 0345 464 0079 or drop us an email for an honest opinion and a quote.
Why Haslar clients choose us
- Arbo and Everbuild products
- Sanitary silicone with an anti-fungal additive in wet areas
- Colour picked to suit the job
- 180+ five-star Google reviews
Read how sealant jobs are priced or our reviews.