Oxfordshire · England
Sand mastic for sash & case windows in Kennington, Oxfordshire
Sand mastic in Kennington from a team with over 20 years’ experience. Rated 4.9 on Google from 180+ five-star reviews.
- Old sand mastic that has cracked, crumbled or fallen out
- Tired mastic found when preparing windows for paint
- Patchy fillers round a sash window
Sand mastic in Kennington
A silicone bead around a sash window can look out of place and does not suit the building. Sand mastic is the traditional choice and we can swap the silicone for it. If you’re dealing with cracked mastic round a front door frame and window mastic to renew ahead of painting, we can help, whatever the surface.
In smaller places like Kennington, homes range from older cottages to newer houses, with windows to match: timber, uPVC and aluminium. The right sealant depends on the frame and on what it sits in.
We stand behind the work with a 12-month guarantee, so you’re covered after we have gone.
- Where
- Kennington (OX1, OX14)
- Wider area
- Oxfordshire
- Cover
- One year on every job
- Price
- A clear price before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
How it works
All our tools and materials come with us in the van. After a quick look at the joints together, we protect the area and start. Most jobs take a few hours per window, depending on the condition of the joints. Parking around Kennington 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.
- We check each window surround and the condition of the joint.
- We rake out the old mastic and clean the joint.
- Large voids are packed out.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
Before we arrive
- Try not to wet indoor joints just before the visit
- For business premises, tell us about site rules or sign-in
- Plan for the work area to be out of bounds to pets and children
Getting a quote
For a quote, call 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You’ll have a clear quote before we start.
Advice
DIY versus a professional finish
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it doesn’t work out, we can still put it right.
The difference is mostly in the preparation and the product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Kennington: your questions answered
Is Kennington in your area for sand mastic?
Yes. We work across London and the South East, and Kennington is part of that. You can phone 0345 464 0079 or send us an email and tell us what needs doing, and we will give you a clear quote.
Do you cover smaller places like Kennington?
Yes, Kennington is covered. We work across London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
How long does sand mastic take?
A typical job takes anything from a few hours to a full day, depending on how many windows. We’ll confirm how long when we quote.
Can you match the sealant colour?
In most cases you can choose. We will tell you which colours the right product comes in and agree one before any work starts.
How much does sand mastic cost in Kennington?
The cost depends on the size of the job, access and how much old sealant has to come out. Call for a quick quote and we’ll talk you through it.
Which products do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We’ll tell you what we’re using and why.
Can tenants book the work?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Are you fully insured?
Yes. We’re fully insured, and we have been doing sealant work for more than 20 years.
Work for landlords, hotels and businesses
Water getting past a failed joint can damage the building, which is a bigger problem in a rented property. Keeping joints in good order is simple maintenance that we can handle for you.
For anyone letting property in or around Kennington, jobs at different addresses can go on one quote. Send us the addresses and the work at each.
What affects the cost of sand mastic
Jobs vary more than people expect. What affects the quote:
- The size of the job
- How many areas need sealing
- Whether the work is at height
- Mould in or behind the old joints
There are no prices on our website, because each job is priced on what it involves. Call for a quick quote.
What to tell us for a quote
You don’t need to know the technical terms. Just tell us:
- Photos by email, if that’s easy
- The rough size of the job
- Where the job is, and your postcode
- If it’s domestic, commercial or a hotel
It all starts with a short chat. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, call 0345 464 0079 or email us.
When it isn’t the sealant
Some problems need a builder, plumber or other trade rather than us:
- Decayed frames that need repair
- Masonry that needs repairing
- Cracked or broken glass
If in doubt, call 0345 464 0079 or send us an email and we will say what we think before booking.
What we seal
- Timber door frames
- Sash and case windows
- Period & listed homes
- Stone surrounds
- Brick reveals
- Tenement windows
Looking after it afterwards
So the new joints stay in good condition:
- Check with your local planning authority if your home is listed
- Go gently near the mastic when preparing windows
- Keep modern sealant off the mastic
- Do not paint over the new mastic
When preparing windows for paint, take care around the mastic. It can be damaged by heavy scraping.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall, so renewing it early is worth it.
Sand mastic in Kennington: local notes
Compared with the north and west, the South East gets less rain, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. Historic houses like Holywell Manor (about 3.1 miles north) are a reminder that the area around Kennington 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.
If you look after a building such as St Swithun's CofE Primary School, the mastic around its windows and doors needs looking after like any other building’s. Rented homes near Radley station change hands often, and older sash windows in a rental need their mastic kept sound to keep the weather out.
Kennington is about 3 miles south of Oxford, in Oxfordshire. Every kind of property in Kennington can book us for sand mastic. The work is guaranteed for a year. Kennington is one of 443 places in Oxfordshire where we work.
Here we cover the OX1 and OX14 postcode area for sand mastic. Streets in the area include Simpsons Way, The Avenue and Liddiard Close, and we cover them all. Neighbouring places we cover for sand mastic include Sandford-on-Thames (1 mile east), Littlemore (1 mile north-east), Redbridge (1 mile north), Hinksey Hill (1 mile north-west) and Bayworth (1 mile west). Larger places within reach include Oxford (3 miles north), Didcot (7 miles south), Bicester (14 miles north), Abingdon-on-Thames (3 miles south-west), Witney (12 miles north-west) and Carterton (15 miles west).
Around Kennington
We work in homes and buildings around The Oxford Academy, Emmanuel Christian School and The Tandem pub. The nearest railway station is Radley station, roughly 1.8 miles south. Nearby you will also find Templars Square (1.9 miles north-east) and Oxford Castle and earlier settlement remains (2.9 miles north). For a walk, there’s Lashford Lane Fen and Harcourt Hill.
When to call us in Kennington
Paint, silicone or cement used over old mastic causes problems. They do not move with the timber and we normally remove them.
These are the problems we’re asked about most:
- Mastic worn away on windows facing the weather
- Window mastic to renew ahead of painting
- Gaps round a timber door in stone or brick
- Patchy fillers round a sash window
If you live in an older home near St Swithun's Church, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint.
Before booking anyone
- How the joint is cleaned and prepared
- What happens if they find a problem under the old sealant
- Is VAT in the price?
- What guarantee comes with the work