Hampshire · England
Knightwood Sand Mastic
Sand mastic across Knightwood and nearby, with old sealant always removed completely.
- Wind and rain getting in round a sash window
- Cement or filler used on old window joints that has cracked
- Failed mastic on an exposed elevation
How we handle sand mastic in Knightwood
Sand mastic doesn’t last for ever, leaving gaps round the window. We rake it out and renew it so the surround looks right again. If you’re dealing with window mastic to renew ahead of painting and mastic worn away on windows facing the weather, we can help, whatever the surface.
Many houses in smaller places like Knightwood have conservatories, garden rooms or patio doors. Those joints need the same attention as the main windows.
There’s a 12-month guarantee on every job, large or small.
- Place
- Knightwood (SO53, SO52)
- Region
- Hampshire
- Guarantee
- One year on every job
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What affects the quote in Knightwood
For a quick quote, just ask. What matters most is:
- How many areas need sealing
- The number and length of the joints
- Whether the work is at height
- Whether there’s mould to deal with
Instead of a standard rate, we look at what your job involves: the amount of work, the old material and the access. You’ll know the price before we begin.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- Any previous sealing or DIY work
- Access, such as stairs, a lift or height
- The address or postcode of the job
- What’s wrong with the joints now
If you are in Knightwood and need sand mastic, phone 0345 464 0079 or send us an email. Tell us what the problem is and where, and you will get a clear quote before work begins.
Landlords, agents and businesses in Knightwood
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. We can quote for more than one property at once.
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements.
What sealant work cannot fix
It helps to know what we can’t do too:
- Damaged stone surrounds
- Rotten sashes, sills or window boxes (a joiner’s job)
- Sash cords, weights and draught-proofing of the sashes
Not sure which it is? You can ring 0345 464 0079 or drop us an email and we’ll tell you honestly.
Surfaces we seal
- Timber door frames
- Tenement windows
- Stone surrounds
- Brick reveals
- Period & listed homes
- Sash and case windows
Why act early in Knightwood
Cement-based fillers and modern sealants do not always suit a period surround. Sand mastic matches what was there and that can be important for listed homes. Around Knightwood, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
The cost depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts, so you know where you stand.
Why book with us
- Homes, businesses and hotels
- ARBOMaster approved applicator
- We leave the area clean and tidy
- We’re fully insured
Read our cost guide or our reviews.
How it works
At the end, we look at the finished work together and explain the cure time. The work normally takes a few hours per window, depending on the condition of the joints, depending on the amount of work. Parking around Knightwood is generally 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.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Preparing for the visit
- Keep pets and children clear of the area while we work
- Tell us about any previous sealing or DIY attempts
- Tell us about access, such as stairs, a lift or high-level joints
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.
Related advice
Knightwood: your questions answered
I let a flat near Chandlers Ford station. Can you help?
Yes, landlords and agents are among the people we work for. You can call 0345 464 0079 or email us with the details for a clear quote.
Is Knightwood in your area for sand mastic?
Yes. Our work covers London and the South East, and Knightwood is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing, and we’ll give you a clear price.
What’s sand mastic made of?
Sand plus a binder based on linseed oil. It’s applied by hand and shaped to suit the surround.
How long does sand mastic take to go off?
A skin forms quite soon, but full hardening takes longer. We’ll tell you what to expect for your job.
What should I tell you?
The location, the problem and the rough size of the job. If you can, email a few photos.
How long does the job take?
It depends on the size of the job, but as a guide it takes a few hours per window, depending on the condition of the joints. We will tell you when we quote.
Will it make a mess?
No. We protect the surfaces around the joints, and we clear up the old sealant and our materials before we leave.
Is it OK to seal over old sealant?
No, and we never do. It can look neat for a few weeks, but the new layer lifts away from the old one. The old sealant has to come out completely.
DIY versus a professional finish
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
A DIY attempt does not rule out a professional job. We remove it and do the joint properly, so just mention it when you contact us.
What we’re called out for in Knightwood
Some old mastic was never deep enough. Mastic that is too thin cracks and drops out, which is why we pack deep voids first and get the depth right.
Most people get in touch when they notice something like this:
- Gaps round a timber door in stone or brick
- A silicone bead on a sash window that spoils the look
- Cement or filler used on old window joints that has cracked
- Tired mastic found when preparing windows for paint
Managing a site like Knightwood Primary School? Then its window and door frames need their mastic kept sound, just like a home’s.
Comparing quotes
- Whether you can choose the colour
- How long the guarantee is
- Is VAT in the price?
- What insurance they hold
Windows and doors in Knightwood
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. Historic houses like South Stoneham House (about 3.7 miles south) are a reminder that the area around Knightwood 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.
In the older streets around St Francis, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. If you let a flat or house near Chandlers Ford station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Knightwood is about 1 mile west of Chandler's Ford, in Hampshire. Knightwood gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our area takes in 683 places across Hampshire, from the larger towns to small villages.
Postcode districts we cover here for sand mastic: SO53 and SO52. Whether your property is on Foyle Road, Harvest Road and Flexford Road or anywhere close by, we can help. We also cover the places around Knightwood: Chilworth Old Village (2 miles south-west), Chilworth (2 miles south), North Baddesley (2 miles west), Toothill (3 miles south-west) and Bassett (3 miles south). Larger places within reach include Winchester (6 miles north-east), Eastleigh (3 miles south-east), Fareham (13 miles south-east), Totton (7 miles south-west), Hedge End (7 miles south-east) and Romsey (4 miles west).
Landmarks near Knightwood
We work in homes and buildings around Toynbee School. Knightwood’s nearest station is Chandlers Ford station, about 0.8 miles south-east of the centre. Nearby you will also find Romsey Community Hospital (3.5 miles west) and Eastleigh Museum (2.5 miles south-east). For a walk, there’s Flexford Nature Reserve.