Hampshire · England
Sand mastic for sash & case windows in Gosport, Hampshire
Professional sand mastic in and around Gosport, with old sealant always removed completely and a one-year guarantee.
- Cement or filler used on old window joints that has cracked
- Mastic that needs renewing before redecorating
- A silicone bead on a sash window that spoils the look
FAQs for Gosport
I let a flat near Portsmouth Harbour station. Can you help?
Yes. We work for letting agents and landlords as well as householders. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear price.
Does the coastal weather in Gosport affect outside sealant?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. The right product, a clean joint and the right depth all help it cope.
Is sand mastic better than silicone for my windows?
It depends on the window. On many period windows, sand mastic looks right and suits the building and newer frames usually get a flexible sealant.
What guarantee comes with the work?
You get our 12-month guarantee on every job.
Should I check with the council before work on a listed or conservation-area home?
Checking first is sensible. Ask your local planning authority whether consent is needed for work on a listed home or in a conservation area.
What information do you need?
Tell us what needs doing and where, plus pictures if you have them. We’ll ask anything else we need to know.
How much does sand mastic cost in Gosport?
Every job is different, so each one gets its own quote. To get one, ring 0345 464 0079 or send us an email with a short description of the job.
Can old silicone round a sash window be swapped for sand mastic?
Yes, it’s a common request. All the old silicone is removed first so the mastic beds in well.
Sand mastic in Gosport, done properly
Burnt sand mastic is a traditional material blends with stone and brick surrounds. It’s a good fit for period properties, where modern sealant can look out of place. Common call-outs are for draughty sash windows at the surround and gaps where the frame meets the masonry, across tenement windows, sash and case windows and brick reveals.
In a town like Gosport, the windows on the most exposed side of a house take the brunt of the rain, and that’s normally where the sealant gives up first. It’s worth looking at every frame, not just the one that leaks.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Gosport (PO12, PO13)
- Region
- Hampshire
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Places near Gosport
Other services in Gosport
DIY versus a professional finish
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas need the right product, the right access and the right method.
If you are set on DIY, put the effort into preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it doesn’t work out, we can still put it right.
The process
Most of a good job is in the preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes anything from a few hours to a full day, depending on how many windows. In Gosport, parking is rarely complicated, though it helps to know about driveways or restrictions, and mention if the work is upstairs, in a flat or high on the outside.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- The surface is finished to suit the stone or brick.
Preparing for the visit
- Mention any sign-in or site rules at work premises
- Mention if the joints have been sealed before
- Clear the area around the work
Getting a quote
Every job is quoted individually. Just phone 0345 464 0079 or email us with the details.
Read more
When it is not the sealant
We will always be straight with you, so here’s what new sealant will not do:
- Decayed frames that need repair
- Damaged stone surrounds
- Planning or listed building consent (your local planning authority decides)
If you are not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer.
What we seal
- Brick reveals
- Tenement windows
- Timber door frames
- Stone surrounds
- Sash and case windows
- Period & listed homes
Frames and glazing around Gosport
Gosport is close to the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That is hard on the mastic around older windows and doors, especially on the side facing the sea. Rainfall in the South East is lower than in much of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
If you let a flat or house near Portsmouth Harbour station, older sash windows in a rental need their mastic kept sound to keep the weather out. Managing a site like Brockhurst Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Gosport is in Hampshire. Every kind of property in Gosport can book us for sand mastic. Every job comes with our one-year guarantee. Our Hampshire coverage runs to 683 places, and Gosport is one of them.
Work in PO12 and PO13 works the same way as everywhere else we cover. If you need sand mastic at a property on Station Road, St Johns Square and Cockleshell Square or a nearby road, our applicators can take on the job. You’ll find Gosport on the A32 and B3333, so it’s easy for us to get to. We also cover Forton (1 mile south-east), Elson (1 mile north), Priddy's Hard (1 mile east), Bridgemary (1 mile north-west) and Rowner (2 miles north-west). Larger places within reach include Havant (8 miles north-east), Eastleigh (14 miles north-west), Fareham (4 miles north-west), Horndean (9 miles north-east), Hedge End (10 miles north-west) and Waterlooville (8 miles north-east). As one of the bigger places in Hampshire, Gosport has every kind of property, from flats to offices.
Near you in Gosport
Typical jobs here are in homes near St Vincent College, Brune Park Community School and Queen's Head pub. Gosport’s nearest station is Portsmouth Harbour station, about 2 miles east. Nearby you will also find Search (1.3 miles south-east) and Gosport War Memorial Hospital (0.8 miles south). For a walk, there’s Portsdown Hill and West of the River Alver.
Aftercare tips
How long the joints last depends on use and care. Here’s what we suggest:
- Avoid heavy scraping on the mastic joint
- Don’t run silicone over sand mastic
- Ask the planning authority about consent for listed or conservation-area homes
- Make sure water runs off the sill
Leave the new mastic unpainted, as traditional guidance advises. Ask us before any decorating around it.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.
Quotes for sand mastic in Gosport
We do not publish a price list, because no two jobs are the same. What we look at:
- How much old sealant there is and how hard it is to remove
- Mould in or behind the old joints
- How many areas need sealing
- The type of sealant required
Some things make a job bigger or smaller: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. We take all of that into account in your quote.
What we need to know
Before you ask for a quote, have a think about:
- A few pictures by email, if you can
- Where the job is, and your postcode
- Access, such as stairs, a lift or height
- The problem you’ve noticed
For sand mastic in Gosport, ring 0345 464 0079 or email us. Tell us what the problem is and where, and you’ll get a clear quote before any work starts.
Work for landlords, hotels and businesses
We work for letting agents and landlords as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
We also work for property managers and facilities teams in Gosport and across Hampshire. Several sites can be quoted together, and we’re fully insured.
What we’re called out for in Gosport
Timber swells and shrinks with the weather. The movement cracks the mastic little by little.
People usually contact us after spotting something like this:
- Mastic round period door frames that has failed
- Mastic worn away on windows facing the weather
- Draughty sash windows at the surround
- Modern sealant on a period surround
Homes close to St Faith's Church include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
What to look for in a quote
- What insurance they hold
- How long to leave it before use
- What preparation is included
- How long the guarantee is