Southampton · England
Sand mastic for sash & case windows in Chartwell Green, Southampton
Professional sand mastic in and around Chartwell Green, with old sealant always removed completely and a 12-month guarantee.
- Open joints round the window box
- Window mastic to renew ahead of painting
- Draughts and rain around sash boxes
Sand mastic in Chartwell Green
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, applied by hand. On period homes, it looks right where silicone wouldn’t. We work on tenement windows, stone surrounds and brick reveals, and common reasons people get in touch are mastic worn away on windows facing the weather and gaps round a timber door in stone or brick.
Houses in smaller places like Chartwell Green can stand more in the open than those in a built-up town. That is hard on the mastic around frames and sills.
Whatever the size of the job, it’s backed by our one-year guarantee in Chartwell Green and across Southampton.
- Place
- Chartwell Green (SO18, SO30)
- Region
- Southampton
- Cover
- 12 months on all our work
- Price
- A clear quote up front
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Work for landlords, hotels and businesses
In hotels, rooms out of use cost money, so the work can be planned room by room around your bookings where we can. We’ve worked in hotels as well as homes and businesses.
Businesses can book us for washrooms, kitchens, offices and more. For commercial premises, we can talk through working times when we quote.
What we do, step by step
You don’t need to clear the whole room or building before we come, only the area right around the joints. Everything nearby is protected, and the work takes a few hours per window, depending on the condition of the joints in most cases. Parking around Chartwell Green is normally easier than in a town centre, but mention any lanes, gates or long drives. If the job is outside, tell us about side access and how high the joints are.
- Each surround is checked first.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- New sand mastic is applied and shaped by hand.
- We finish the mastic to a tidy line.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- For indoor joints, keep the area dry beforehand if you can
- Mention any tricky access
Ask for a quote
We quote each job on its own, so start by telling us what you need. Just call 0345 464 0079 or email us with the details and send pictures if you have them.
Related advice
What we are called out for in Chartwell Green
Timber swells and shrinks with the weather. That movement opens up the mastic joint little by little.
Most people get in touch after spotting one of these:
- Draughty sash windows at the surround
- Gaps round a timber door in stone or brick
- Failed mastic on an exposed elevation
- Patchy fillers round a sash window
In the older streets around Church of St James, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
What your quote should include
- Who turns up on the day
- Whether they’re fully insured
- How the colour is chosen
- Is VAT in the price?
Can I do it myself?
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs call for the right materials, safe access and experience.
Too much sealant is as bad as too little. A heavy bead looks messy and copes badly with movement, and the joint depth matters as much as the finish.
Also near Chartwell Green
Other services in Chartwell Green
Common questions in Chartwell Green
Can you help a landlord with a rental near Swaythling station?
Yes, rental work is part of what we do. You can phone 0345 464 0079 or send us an email with the address and a few details, and we will give you a fixed price before any work starts.
Do you cover Chartwell Green for sand mastic?
Yes, Chartwell Green is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will give you a clear price.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so the joint is cleaned back first.
What guarantee comes with the work?
You get our one-year guarantee on every job.
What 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.
What information do you need?
Only a few details: the address or postcode, what’s wrong and any access issues. Then ring 0345 464 0079 or send us an email.
Are you insured?
Yes. We are fully insured, and we can confirm the details when we quote.
Is it possible to take out silicone and use sand mastic instead?
Often, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
What we cannot put right
A few problems are outside what sealant work can do:
- Planning or listed building consent (your local planning authority decides)
- Sashes that rattle, stick or will not open
- Timber that has rotted
Not sure which it is? You can phone 0345 464 0079 or send us an email and we’ll tell you honestly before booking.
Surfaces we seal
- Stone surrounds
- Timber door frames
- Period & listed homes
- Brick reveals
- Tenement windows
- Sash and case windows
How the job changes by surface
Tenement and terrace windows
Where a building is shared, window work may involve neighbours so it’s worth checking responsibilities.
Timber door frames
Sand mastic is used round timber door frames too. We renew it the same way as on windows.
Keeping the joints in good condition
Looking after new joints is easy, and it makes a real difference:
- Go gently near the mastic when preparing windows
- Keep modern sealant off the mastic
- Make sure water runs off the sill
- Renew mastic before redecorating the windows
Don’t touch or press the mastic while it hardens. It forms a skin fairly soon but needs longer to fully harden.
An open joint round the box lets weather through. Left, the gap tends to get bigger as more mastic falls out.
Sand mastic in Chartwell Green: local notes
Historic houses like South Stoneham House (about 1.3 miles west) are a reminder that the area around Chartwell Green has older buildings as well as new. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic. 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.
For site and facilities teams at buildings such as Townhill Infant School, its window and door frames need their mastic kept sound, just like a home’s. If you let a flat or house near Swaythling station, any sash windows need sound mastic to keep draughts and rain out.
Chartwell Green is about 2 miles north-east of Southampton, in Southampton. Whether you are in the middle of Chartwell Green or further out, sand mastic is available for homes and businesses alike, from flats and houses to offices and hotels. 40 places in Southampton are on our list, large and small.
Every address in SO18 and SO30 is covered for sand mastic, from the main roads to the quietest streets. That includes homes and businesses on Ivy Lane, Arun Road and Eden Road and the roads around them. If you’re just outside Chartwell Green, we cover Townhill Park (1 mile west), West End (1 mile east), Midanbury (1 mile south-west), Mansbridge (1 mile north-west) and Harefield (1 mile south). We also work in nearby towns such as Shirley (4 miles west), Regents Park (4 miles west), Maybush (4 miles west), Woolston (3 miles south-west), Coxford (4 miles west) and Freemantle (4 miles west). Being one of Southampton’s larger places, Chartwell Green has every kind of property, from flats to offices.
Near you in Chartwell Green
In Chartwell Green, that means homes and buildings near Itchen Valley Country Park, Bitterne Park School and The Gregg School. Chartwell Green’s nearest station is Swaythling station, roughly 1.4 miles north-west. Other landmarks nearby include Netley Castle (3.7 miles south) and Marlands Shopping Centre (2.9 miles south-west). Not far away are Netley Common.