West Sussex · England
Sand mastic for sash & case windows in South Mundham, West Sussex
Sand mastic in South Mundham from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Cement or filler used on old window joints that has cracked
- Mastic worn away on windows facing the weather
- A silicone bead on a sash window that spoils the look
Sand mastic in South Mundham
Sand mastic is the traditional way to point the gap between a timber window frame and the stone or brick around it. It’s made from sand and a linseed-oil-based binder and built up by hand. On period homes, it looks right where silicone wouldn’t. We work on stone surrounds, tenement windows and brick reveals, and people most often call us about mastic that needs renewing before redecorating and mastic worn away on windows facing the weather.
In a village or hamlet like South Mundham, older cottages and farmhouses often have timber windows set in stone or brick. Older buildings like these don’t always suit modern silicone, and sometimes a traditional sand mastic is the better choice.
Whatever the size of the job, it’s backed by our one-year guarantee.
- Where
- South Mundham (PO20)
- Wider area
- West Sussex
- Guarantee
- A year, on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Common problems we fix in South Mundham
Rain on the window surround works into any crack and pushes it out. Windows facing the weather tend to go first.
The problems people generally mention when they call include:
- Wind and rain getting in round a sash window
- Crumbling sand mastic round a window
- Gaps round a timber door in stone or brick
- Cement or filler used on old window joints that has cracked
Rented homes near Chichester station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Questions to ask before you book
- Are they insured?
- Which sealant they’ll use, and why
- The length of the guarantee
- Who turns up on the day
How the visit works
We keep the work tidy and contained to the joints we are treating. 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 South Mundham, 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.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Getting ready for the visit
- On commercial sites, let us know about site rules
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about stairs, lifts or work at height
Getting 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.
Advice
Towns and villages near South Mundham
Other services in South Mundham
Work for landlords, hotels and businesses
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
Letting agents and landlords in South Mundham can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order.
Surface by surface
Period and listed homes
Many older homes were built with sand mastic round the windows. On listed buildings, check with your planning authority first.
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Aftercare tips
So the new joints stay in good condition:
- Don’t paint over the new mastic
- Avoid patching sand mastic with silicone
- Plan mastic work ahead of painting
- Check the mastic when you check the paintwork
Keep gutters and sills clear so water runs away from the surround. Water sitting against the mastic shortens its life.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger.
Quotes for sand mastic in South Mundham
We don’t publish a price list, because jobs vary so much. What we look at:
- How many areas need sealing
- Any mould that needs treating
- The product the joint needs
- How easy the joints are to reach
Combining jobs into one visit is usually more efficient than separate visits, so tell us about everything that needs sealing. You’ll get one clear quote for the whole job.
What to tell us for a quote
There’s no need for technical detail. It helps if you can tell us:
- The type of property
- Whether it has been sealed before
- The problem you’ve noticed
- The address or postcode of the job
Every job is quoted individually, so the first step is telling us about yours. Just ring 0345 464 0079 or drop us an email with the details and send photos if you have them.
FAQs for South Mundham
I let a flat near Chichester station. Can you help?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before work begins.
Does the coastal weather in South Mundham affect outside sealant?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
Can I do it myself?
It depends on the job. High-level, external movement and fire-rated joints are professional jobs, while a short indoor joint may be within reach.
What’s sand mastic made of?
It’s a mix of sand and a linseed-oil-based binder. It’s applied by hand and finished to sit neatly against the masonry.
Will there be a smell?
That depends on the sealant. Some products have a noticeable smell, others very little.
How long will you be here?
Typically it takes a few hours per window, depending on the condition of the joints. Larger jobs naturally take longer, and we’ll tell you how long to expect.
Do you come to South Mundham?
Yes. We work in South Mundham and the rest of West Sussex. For a quote, call 0345 464 0079 or send us an email.
What do you put in the joint?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference.
Should I try it myself first?
The biggest DIY mistake is sealing over old sealant. New silicone won’t bond to old, so it lifts and traps water and mould underneath. All the old material has to come out first.
If you’re 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.
Windows and doors in South Mundham
South Mundham 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. Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
In the older streets around The Parish Church of St Stephen, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as North Mundham Primary School, its window and door frames need their mastic kept sound, just like a home’s.
South Mundham is about 3 miles south of Chichester, in West Sussex. South Mundham gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. We cover 371 towns and villages across West Sussex. We also work in Portsmouth, about 14 miles from South Mundham.
Postcode districts we cover here for sand mastic: PO20. You will find streets such as Manor Lane and Honer Lane, all of which we cover. We also cover Fisher (1 mile west), Street End (2 miles south-west), Sidlesham Common (2 miles west), Nyetimber (2 miles south-east) and Sidlesham (2 miles south-west). We also work in nearby towns such as Bognor Regis (3 miles east), Chichester (3 miles north), Selsey (5 miles south), Littlehampton (10 miles east), Emsworth (9 miles north-west) and Rustington (11 miles east).
Local landmarks in South Mundham
We work in homes and buildings around Chichester High School For Girls and Avisford and the streets around them. The closest station to South Mundham is Chichester station, about 2.5 miles north-west of the centre. Nearby you’ll also find Chichester Castle (3 miles north) and Chichester Cathedral Treasury (2.7 miles north-west).