Hampshire · England
Alverstoke Sand Mastic
Sand mastic for Alverstoke, by sealant specialists with 20+ years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Draughty sash windows at the surround
- Silicone on a period window that looks wrong
- Mastic round period door frames that has failed
FAQs for Alverstoke
Does the coastal weather in Alverstoke affect outside sealant?
Coastal homes put outside sealant through more weather than inland ones, so the choice of sealant and the preparation matter even more. It’s worth checking the walls that face the sea first.
I let a flat near Portsmouth Harbour station. Can you help?
Yes, rental work is part of what we do. You can call 0345 464 0079 or email us with the address and a few details, and we will give you a fixed price before any work starts.
What do you need from me for a quote?
Only a few details: where it is, what you’ve noticed and how we reach it. Then phone 0345 464 0079 or email us.
What guarantee comes with the work?
Every job comes with our one-year guarantee.
Can you match the sealant colour?
Normally, yes. Sealants come in white, clear, grey and other colours for many products, and we’ll agree it with you first.
Can you quote for more than one area?
Yes, we can. Several rooms, windows or areas can go on one quote.
What do you put in the joint?
The product depends on the job: anti-fungal sanitary silicone in wet areas, and other sealants where joints move or face the weather. We use products from Arbo and Everbuild.
How long does sand mastic take to harden?
It skins over fairly quickly but takes longer to harden fully. We will explain what to expect before we leave.
Sand mastic in Alverstoke
Sand mastic has long been used to fill the joint between timber frames and masonry. It’s made from sand and a linseed-oil-based binder, applied by hand. On older homes, it suits the building far better than silicone. If you’re dealing with weathered mastic on the most exposed windows and a silicone bead on a sash window that spoils the look, we can put it right, whatever the surface.
Mastic can only go onto a dry, clean joint, so window work in Alverstoke is booked around the forecast. Let us know about access to all the frames, upstairs ones included.
Each job carries a 12-month guarantee.
- Place
- Alverstoke (PO12)
- Wider area
- Hampshire
- Cover
- A year, on every job
- Quote
- A clear quote up front
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Other services in Alverstoke
What affects the quote in Alverstoke
We quote each job individually. This is what makes a difference:
- The old material and how stubborn it is
- Whether the work is at height
- The type of sealant required
- The number of rooms or windows
Commercial jobs are quoted on the same basis as homes: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we’ll explain what it covers.
What to tell us for a quote
Photos by email are helpful but not essential. Please mention:
- A few photos by email, if you can
- What the problem is, such as mould, gaps, leaks or cracking
- How we’d reach the joints
- The address or postcode of the job
There’s no standard price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, call 0345 464 0079 or email us.
Should I try it myself first?
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 does not work out, we can still put it right.
A DIY attempt doesn’t rule out a professional job. We remove it and do the joint properly, so tell us about it when you ask for a quote.
Windows and doors in Alverstoke
Alverstoke is close to the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on the mastic around older windows and doors, which can dry out and crack sooner where a building faces the weather. 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.
For an older house near a landmark such as The Little Church, the joint between an old wall and a newer frame is usually the first place rain gets in. Managing a site like Alverstoke Community Infant School? Then the mastic around its windows and doors needs looking after like any other building’s.
Alverstoke is about 2 miles south of Gosport, in Hampshire. Whether you’re in the middle of Alverstoke or further out, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Alverstoke is one of 683 towns and villages in Hampshire where we work for sand mastic.
We work across the PO12 postcode area for sand mastic. That includes homes and businesses on The Lane, Fort Road and Church Road and the roads around them. If you’re just outside Alverstoke, we cover 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).
What’s near Alverstoke
Around Alverstoke, our work takes us to homes and buildings near Bay House School and Village Home pub. The closest station to Alverstoke is Portsmouth Harbour station, about 2.1 miles north-east. Well-known places in the area include Tricorn Centre (3 miles north-east) and Gosport War Memorial Hospital (0.9 miles north). The countryside around Alverstoke includes West of the River Alver.
What happens if it’s left?
A silicone bead can be quicker, but on period stone or brick it often looks out of place. Sand mastic suits the building and blends with the stone or brick. Older cottages and farmhouses around Alverstoke can have timber floors and frames, and water through a failed joint can rot timber if it’s left.
Rather than a set price list, we price the job in front of us: the amount of work, the old material and the access. You will know the price before we begin.
What you get with us
- ARBOMaster approved applicator
- Fully insured
- Quality sealants from Arbo and Everbuild
- Every job guaranteed for a year
Take a look at what affects the cost and what customers say.
How to look after the new joints
To keep the joints looking good and working properly:
- Leave the new mastic unpainted
- Get any rot dealt with first
- Make sure water runs off the sill
- Look over the window mastic once a year
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at before trying a quick fix.
Renewing mastic before redecorating saves doing it twice. Painting over failed mastic hides the problem for a while.
Do you need sand mastic in Alverstoke?
Paint, silicone or cement used over old mastic causes problems. They do not suit the joint, and they normally need raking out.
If you can see any of these, it’s time to have the joints looked at:
- Mastic that needs renewing before redecorating
- Gaps where the frame meets the masonry
- Mastic round period door frames that has failed
- Old cement repairs round a window that have failed
If you let a flat or house near Portsmouth Harbour station, any sash windows need sound mastic to keep draughts and rain out.
Comparing quotes
- Whether they seal over old material or remove it
- How long to leave it before use
- How the joint is cleaned and prepared
- Which colour the sealant will be
Different surfaces, different methods
Stone surrounds
The stone is treated with care while raking out the old mastic.
Period and listed homes
Sand mastic is the like-for-like choice for many period homes. If your home is listed, ask your local planning authority about consent.
How the visit works
We keep the work tidy and contained to the area we are working on, so you can get on with your day. Expect the work to take a few hours per window, depending on the condition of the joints, and we tell you how long to leave it before we go. For a village or hamlet like Alverstoke, the journey is planned in advance: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Mention any parking rules near the property
- On commercial sites, let us know about site rules
- Tell us about access, such as stairs, a lift or high-level joints
How to get a quote
Getting a quote is simple: tell us what needs doing and where, and roughly how big it is. Photos by email help us understand the job.