Portsmouth · England
Hilsea Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Hilsea, with a one-year guarantee on every job. Ask us for a quote.
- Mastic that needs renewing before redecorating
- Old sand mastic that has cracked, crumbled or fallen out
- Cracked mastic round a front door frame
Sand mastic in Hilsea
We work across Hilsea renewing sand mastic on sash windows and doors. Every joint is cleaned out and filled by hand, finished to suit the masonry. We work on timber door frames, sash and case windows and brick reveals, and people most often call us about patchy fillers round a sash window and gaps where the frame meets the masonry.
In a smaller place like Hilsea, some walls face open ground and catch the full force of the weather. The mastic around frames on those walls tends to age faster.
Whatever the size of the job, you get the same one-year guarantee in Hilsea and across Portsmouth.
- Location
- Hilsea (PO2, PO3, PO6)
- Wider area
- Portsmouth
- Cover
- 12 months on all our work
- Quotes
- A clear price before work begins
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What we do, step by step
All our tools and materials come with us in the van, so you do not need to buy or prepare anything. Once we’ve agreed what’s being done, we protect the area and start. It normally takes a few hours for a single window, longer for several. A visit to Hilsea is planned like any other: the time, the access and where to park are agreed in advance. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- First, we look at the surrounds with you and agree what needs doing.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic isn’t too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The mastic is finished to sit tidily against the stone or brick.
Preparing for the visit
- For business premises, tell us about site rules or sign-in
- Keep children and pets away from the work area
- Let us know about stairs, lifts or work at height
How to get a quote
The more we know about the job, the more useful the quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that’s easy.
Related advice
Hilsea homes and the weather
Hilsea is within about 1 mile of 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 St Francis' Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. Schools such as Gatcombe Park Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s. Rented homes near Hilsea station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Hilsea is about 2 miles north of Portsmouth, in Portsmouth. We carry out sand mastic for homeowners, landlords and businesses in Hilsea and the surrounding area. Our Portsmouth coverage runs to 19 places, and Hilsea is one of them.
Every address in PO2, PO3 and PO6 is covered for sand mastic, from the main roads to the quietest streets. Streets in the area include Vita Road, Conan Road and Arras Road, all of which we cover. We also cover the places around Hilsea: Cosham (1 mile north), North End (1 mile south-west), Tipner (1 mile south-west), Wymering (1 mile north) and Rudmore (1 mile south-west). We also work in nearby towns such as Southsea (3 miles south), Portsea (3 miles south-west) and Portsmouth Point (3 miles south-west).
Landmarks near Hilsea
Around Hilsea, our work takes us to homes and buildings near Alexandra Park, Trafalgar School and Coach and Horses pub. Hilsea’s nearest station is Hilsea station, roughly 0.5 miles east of the centre. Nearby you’ll also find World War I Remembrance Centre (0.8 miles east) and Tricorn Centre (2.1 miles south-west). For a walk, there’s Milton Locks and Portsdown Hill.
Honest limits
Before booking, it’s worth knowing the limits too:
- Sash cords, weights and draught-proofing of the sashes
- Rotten sashes, sills or window boxes (a joiner’s job)
- Crumbling stone or brickwork round the window
If in doubt, call 0345 464 0079 or send us an email and we will say what we think.
Joints and surfaces we work on
- Brick reveals
- Stone surrounds
- Timber door frames
- Sash and case windows
- Tenement windows
- Period & listed homes
Aftercare tips
To keep the joints looking good and working properly:
- Renew mastic before redecorating the windows
- Go gently near the mastic when preparing windows
- Avoid patching sand mastic with silicone
- Make sure water runs off the sill
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look rather than patching it.
Good mastic helps keep the frame dry. Failed mastic lets water reach the timber, which can lead to rot.
For landlords and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
Letting agents and landlords in Hilsea can book us as well as householders. Resealing between tenancies keeps a property looking cared for before the next move-in.
Also in Hilsea
Your questions about sand mastic in Hilsea
Does the coastal weather in Hilsea 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.
Do you cover smaller places like Hilsea?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Do you do commercial work?
Yes. We have worked for hotels, offices and other businesses.
Will there be a smell?
Some sealants have a smell while they cure, which fades as it sets. Ventilation helps.
When will the new mastic be hard?
The surface skins quite quickly and it hardens fully over a longer time. The weather and joint depth both affect it.
What should I tell you?
Just the basics: the address or postcode, what’s wrong and any access issues. Then phone 0345 464 0079 or send us an email.
What exactly is sand mastic?
Sand plus a binder based on linseed oil. It’s built up in the joint by hand and shaped to suit the surround.
How long will you be here?
That depends on how much there is to do, but most jobs take a few hours per window, depending on the condition of the joints. We will tell you when we quote.
What the job involves on each surface
Timber door frames
Doors face weather and wear, so their mastic can fail sooner. We rake it out and renew it.
Tenement and terrace windows
Rows of sash windows on tenements and terraces often need renewing together. We work on single windows or whole elevations.
What affects the cost of sand mastic
Your quote is based on your job. We look at:
- How many areas need sealing
- Whether old sealant or filler has to be cut out
- Whether the work is at height
- The product the joint needs
Combining jobs into one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
Asking for a quote
When you contact us, it’s useful to know:
- The rough size of the job
- Where the property is
- Any access issues, like height or stairs
- What the problem is, such as mould, gaps, leaks or cracking
Every job is quoted individually, so the first step is telling us about yours. Just call 0345 464 0079 or email us with the details and send photos if you have them.
DIY sealant or a professional job?
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Some jobs are best left to a professional: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.