Hampshire · England
Window & door mastic in Alverstoke, Hampshire
Mastic around window and door frames, sills and patio doors for homes and businesses in Alverstoke and across Hampshire. ARBOMaster approved applicators, fully insured, with a one-year guarantee.
- White mastic on grey or black frames
- Cracked sealant at the sill ends
- Whistling draughts around closed windows
What we are called out for in Alverstoke
Mastic ages in the weather. UV light hardens the outside of the bead, and over the years it loses its give, cracks and comes away.
Any of these means the joints need attention:
- Hard, cracked sealant around windows
- Black, perished sealant on frames
- White mastic on grey or black frames
- Draughty joints inside around the window
Rented homes near Portsmouth Harbour station change hands often, and cracked frame mastic tends to show up as a draught or damp complaint, so it’s worth checking between lets.
Comparing quotes
- What insurance they hold
- Who turns up on the day
- Is the old sealant removed completely?
- Whether the sealant suits the joint
Window mastic in Alverstoke
Frames and walls do not move together. Plastic and aluminium frames move with the temperature, while masonry stays fairly still. So the sealant has to stretch and recover, which is why we use a low-modulus product. Typical jobs include rain getting in at the frame or under the sill and white mastic on grey or black frames, across patio & French doors, timber windows & doors and uPVC windows.
Somewhere as small as Alverstoke, older homes often have timber frames set in stone or brickwork. Not every older frame suits a modern silicone bead, and sometimes a traditional sand mastic is the better choice.
We guarantee the work for a year. If something is not right with it in that time, tell us and we’ll put it right.
- Location
- Alverstoke (PO12)
- Wider area
- Hampshire
- Cover
- One year on every job
- Quote
- A clear price before work begins
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What affects the cost of window mastic
The price is agreed before any work begins. It takes into account:
- Whether there’s mould to deal with
- Which sealant suits the joint
- Access and height
- When we can work, for business premises
What you pay reflects the work, not a rough estimate. That is why we ask a few questions first.
What we need to know
To make quoting easier, let us know:
- Any previous sealing or DIY work
- Roughly how big the job is
- Pictures of the joints, sent by email
- Any access issues, like height or stairs
For a quick quote, get us on the phone, or email us if that’s easier. Describe what needs sealing and we’ll explain what’s involved and give you a clear price.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it peels away and traps moisture behind it. Everything old must be removed first.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
Alverstoke questions
Do you cover smaller places like Alverstoke?
Yes, smaller places are covered as well as towns. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Does the coastal weather in Alverstoke affect outside sealant?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. Walls facing the sea are normally the first to need attention.
Do you do commercial work?
Yes. We’ve worked for hotels, offices and other businesses.
Can you do the inside joint as well?
Yes. Inside, the joint between frame and plaster is sealed neatly, using a paintable sealant if you want to decorate.
How do I get a quote for window mastic in Alverstoke?
There’s no set price, as it depends on the job: its size, the old material, access and the product needed. We agree the price before any work begins.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before resealing.
How long before the joint can be used?
Many sealants skin over quickly but take longer to cure fully. We will give you the cure time for the product we used.
How many windows can you do in a day?
A handful of frames is a short visit, while a whole house takes longer. You’ll get a timescale with the quote.
What happens if it’s left?
Redecorating is a good moment to renew the mastic. Fresh joints finish the job neatly, and it’s easier while the walls are being worked on anyway. In a small place like Alverstoke, homes can be exposed to wind and rain, which finds any gap, and older walls, once damp, take a long time to dry.
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs. Ask us for a quote and we will go through it with you.
Why Alverstoke clients choose us
- Anti-fungal silicone where joints get wet
- Sealant colour chosen to suit
- Colour agreed with you before any work starts
- White, clear, grey or coloured to suit, where the product allows
Take a look at what affects the cost or what customers say.
What window mastic looks like in Alverstoke
Alverstoke is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. Both are hard on the mastic around window and door frames, which can dry out and crack sooner where a building faces the weather. London and the South East are among the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Homes close to The Little Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Schools such as Alverstoke Community Infant School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Alverstoke is about 2 miles south of Gosport, in Hampshire. Homes, rented property, offices and hotels in Alverstoke can book us for window mastic. Every job comes with our one-year guarantee. Our area takes in 683 places across Hampshire.
Here we cover the PO12 postcode area for window mastic. If you need window mastic at a property on The Lane, Fort Road and Church Road or a nearby road, our applicators can take on the job. Other places close to Alverstoke include Clayhall (1 mile east), Haslar (1 mile east), Privett (1 mile north-west), Portsmouth Point (2 miles north-east) and Portsea (2 miles north-east). Within a short drive, we also cover Havant (9 miles north-east), Fareham (5 miles north), Horndean (11 miles north-east), Hedge End (12 miles north-west), Waterlooville (9 miles north-east) and Purbrook (8 miles north-east).
Local landmarks in Alverstoke
Around Alverstoke, our work takes us to homes and buildings near Bay House School and Village Home pub. For rail, the closest station is Portsmouth Harbour station, roughly 2.1 miles north-east. Other landmarks nearby include Tricorn Centre (3 miles north-east) and Gosport War Memorial Hospital (0.9 miles north). Green spaces nearby include West of the River Alver.
Work for landlords, hotels and businesses
From a single let to a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
We work for landlords and letting agents as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
What happens on the day
Once we are on site, we check the joints match what you told us. If anything is different, we explain it before carrying on. After that, the work takes a few hours for a handful of frames, longer for a whole house. For a village or hamlet like Alverstoke, the journey is planned in advance: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- We start by checking each window and door with you.
- Next the failed sealant is cut away and the joint cleaned.
- We fit backing rod in deep gaps so the sealant is the right depth.
- We apply a weatherproof sealant to match the frame and tool it neatly.
- We clear up and check every joint is fully closed.
Before we arrive
- Try not to wet indoor joints just before the visit
- Mention if the joints have been sealed before
- Mention any leaks or damp you’ve noticed
Ask for a quote
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job.
Related advice
More services for Alverstoke
Surface by surface
Aluminium frames
Aluminium moves with heat, and the frames are often slimmer than uPVC. A tidy bead in anthracite grey, black or a matching colour keeps the clean look.
Composite doors
An exposed front door gets wind-driven rain. We pay most attention there.