Hampshire · England
New-build mastic & snagging in Portchester, Hampshire
Plot mastic for developers and snagging failed sealant in new homes for homeowners, landlords and businesses in Portchester. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- Cracked sealant around new window and door frames
- Shower seals failing in the first year or two
- Beads laid onto grit and dust from the build
About our new build mastic in Portchester
Building dust is behind a lot of failed new-build sealant. Each joint is cleaned of dust and primed where the product calls for it, so the sealant actually sticks. We’re often asked to deal with joints pulling apart as timber shrinks and cracked sealant around new window and door frames, across bathrooms & en suites, kitchens and show homes.
If you’ve bought a new home in or near Portchester, the first year or two is a good time to check the sealant. Common snags include open skirting joints, lifting shower seals and gaps around frames.
The work is guaranteed for twelve months. If something isn’t right with it in that time, tell us and we’ll put it right.
- Place
- Portchester (PO16, PO6, PO17)
- Region
- Hampshire
- Cover
- One year on every job
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Questions from Portchester
Is Portchester within the area you cover?
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.
Can you do new build mastic in Portchester?
Yes. Our work covers London and the South East, and Portchester is part of that. Just ring 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
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. Brands we use include Arbo and Everbuild.
Can new sealant go on top of the old bead?
No. The old sealant is cut out fully, then clean and prime the joint, and a new bead applied.
How long before the joint can be used?
Cure times vary by product and the conditions. We tell you how long to leave it before we go.
Will the old sealant be removed?
Always. Sealing over old sealant is the main reason resealing fails early, so we never do it.
Why has my new-build shower seal failed already?
Cracking in the first couple of years is common, because the house is drying and settling. Rushed application on dusty surfaces makes it worse.
Do you have insurance?
Yes. We are fully insured.
DIY versus a professional finish
If you do try it yourself, take your time over the 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.
The biggest DIY mistake is sealing over old sealant. 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.
What sealant work can’t fix
Honest advice matters more to us than a booking, so here’s what sealant can’t fix:
- Plumbing faults behind the sealant
- Disputes or warranty claims with your builder
- 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.
Joints and surfaces we work on
- Plot handovers
- Kitchens
- Windows & doors
- Skirting & floors
- Show homes
- Bathrooms & en suites
What new build mastic looks like in Portchester
Portchester is within about 1 mile of 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, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
For new homes near Portchester station, it’s worth checking the sealant early, while snags are still fresh.
Portchester is about 3 miles north-east of Gosport, in Hampshire. From the centre of Portchester to the outskirts, new build mastic is available for homes and businesses alike. 683 places in Hampshire are on our list, large and small.
All of PO16, PO6 and PO17 is covered for new build mastic. We cover properties on Cow Lane, Hill Road and Ralph Road. Close by, we work in Boarhunt (2 miles north-west), Southwick (2 miles north), Elson (2 miles south-west), Wallington (2 miles west) and Priddy's Hard (2 miles south). Further out, we also cover Gosport (3 miles south-west), Havant (6 miles east), Eastleigh (13 miles north-west), Fareham (3 miles west), Horndean (7 miles north-east) and Chandler's Ford (15 miles north-west).
Landmarks near Portchester
Locally, jobs take us to homes and businesses close to Portchester Community School and The Cormorant pub and the streets around them. For rail, the closest station is Portchester station, roughly 0.5 miles north-west of the centre. Nearby you will also find Portchester Castle (less than half a mile south-east) and Queen Alexandra Hospital (2.3 miles east). Not far away are West of the River Alver and Portsdown Hill.
How we quote for new build mastic
The price is agreed before any work begins. It’s based on:
- Any mould that needs treating
- The old material and how stubborn it is
- How many areas need sealing
- The product the joint needs
Combining jobs into one visit is generally more efficient than separate visits. You’ll get one clear quote for the whole job.
What we need to know
Photos by email are helpful but not essential. Please mention:
- The problem you’ve noticed
- Where the job is, and your postcode
- Any access issues, like height or stairs
- If someone has resealed it before
Asking for a quote is easy: tell us what needs doing and where. A few pictures by email make the job easier to understand.
Signs you need new build mastic in Portchester
New homes are full of moisture from plaster, screed and concrete, which takes a year or two to dry out. Drying timber shrinks and pulls joints apart, and sealant that cannot keep up splits.
These are the problems we are asked about most:
- Cracked sealant around new window and door frames
- Worktop and upstand sealant coming away
- Plot mastic for developers ahead of handover
- Messy sealant that spoils new finishes
Around Portchester, as everywhere, new build mastic is only as good as the preparation behind it.
What your quote should include
- Are they insured?
- The length of the guarantee
- What happens if the job turns out different
- When the joint can take water or movement
How the job changes by surface
Kitchens
Worktops in new homes can move slightly as the house dries, which opens gaps along the back. A fresh flexible bead closes them.
Skirting and floors
Wet-area floor joints need a flexible seal. They get a flexible, water-resistant sealant.
What happens on the day
We work through the job in order: protect, prepare, seal, tidy. For most jobs that takes a few hours for most snagging lists, longer for a run of plots and we leave things clean and tidy. For a job in Portchester, we agree the time, the access and parking before the day. If the work is outside, the weather plays a part, as sealant needs a dry surface.
- First, the list of joints is agreed from your snagging sheet or plot schedule.
- The failed sealant is removed completely down to clean surfaces.
- We clean out the dust and grit left from the build.
- Primer goes on where the surface and product need it, then the new sealant.
- Each bead is tooled and the cure times explained.
Getting ready for the visit
- Clear items away from the joints we are working on
- Where the joints are inside, avoid wetting them before we arrive
- Mention if the joints have been sealed before
Getting a quote
Call for a quick quote, or send an email if you’d rather. Tell us about the joints that need doing and we’ll talk you through the work.
Advice
Also near Portchester
Also in Portchester
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Open a window or run the fan after bathing
- Avoid scourers and strong chemicals on sealant
- Follow the cure time we give you
- Act quickly if a seal starts to leak
Don’t stand on the bath edge or the lip of the tray. If a bath or tray moves when you stand in it, get it looked at.
If a shower tray or bath seal splits in the first year, look for movement. Getting it resealed properly, and any movement checked, stops it recurring.