Greater London · England
Sand mastic for sash & case windows in Kennington, Greater London
Sand mastic for Kennington and the surrounding area: the right sealant, proper preparation and a neat finish. Ask us for a quick quote.
- Weathered mastic on the most exposed windows
- Draughts and rain around sash boxes
- Tired mastic found when preparing windows for paint
Sand mastic for homes and businesses in Kennington
Sand mastic skins over fairly quickly but full hardening takes longer. Traditional guidance is not to paint over it, so ask us before you decorate. We work on timber door frames, tenement windows and sash and case windows, and the jobs we see most are mastic round period door frames that has failed and open joints round the window box.
Many London homes are flats, with windows high above the street. In a converted house or block, the lease generally says who is responsible for the windows, so it’s worth checking before booking, and access in Kennington is something to talk through when you book.
The work is covered for a year after we finish. If there’s a problem with it, please call 0345 464 0079 or email us.
- Location
- Kennington (SW8, SW1P, SE11)
- Wider area
- Greater London
- Guarantee
- 12 months on all our work
- Price
- A clear quote up front
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
When something else is needed
We’d rather tell you now than do work that will not last, so these are the limits:
- Damaged stone surrounds
- Whether work needs listed building consent
- Broken panes
If you are not sure, just ring 0345 464 0079 or drop us an email and we will give you a straight answer.
What we seal
- Timber door frames
- Tenement windows
- Stone surrounds
- Period & listed homes
- Sash and case windows
- Brick reveals
When to call us in Kennington
Rain on the window surround works into any crack and pushes it out. Exposed elevations generally fail first.
Any of these means the joints need attention:
- Cement or filler used on old window joints that has cracked
- Cracked mastic round a front door frame
- Mastic that needs renewing before redecorating
- Draughts and rain around sash boxes
If you let a flat or house near Vauxhall station, any sash windows need sound mastic to keep draughts and rain out.
What to look for in a quote
- Whether VAT is included
- What insurance they hold
- What guarantee comes with the work
- Which sealant they’ll use, and why
Towns and villages near Kennington
Other services in Kennington
What sand mastic looks like in Kennington
Historic houses like Buckingham Palace (about 1.7 miles north-west) are a reminder that the area around Kennington has older buildings as well as new. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window. In London conversions and blocks, the lease decides who is responsible for the frames, so check that before you book.
Schools such as St Stephen's Church of England Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. Kennington is in London, so parking needs planning: let us know about parking bays, permits or a driveway.
Kennington is about 2 miles south-west of London, in Greater London. Every kind of property in Kennington is covered for sand mastic, old or new, large or small. The work is guaranteed for a year. Kennington is one of 764 towns and villages in Greater London we cover.
All of SW8, SW1P and SE11 is within our area for sand mastic. Sand mastic is available to properties on Kay Road, Lett Road and Rita Road and the roads around them. You’ll find Kennington on the A203 and A3204, so it’s easy for us to get to with everything needed for sand mastic. Other places close to Kennington include Oval (1 mile north), South Lambeth (1 mile south-west), Little Portugal (1 mile south), North Brixton (1 mile south-east) and Vauxhall (1 mile north). Larger places within reach include City of Westminster (3 miles north-west), Marylebone (3 miles north-west), Kensington (4 miles west), St Pancras (3 miles north), Shoreditch (4 miles north-east) and Walthamstow (8 miles north-east).
Landmarks near Kennington
Around Kennington, our work takes us to homes and buildings near St Peter's School, Archbishop Tenison's Church of England School and Lambeth Palace Library and the streets around them. Also close by are Crown and Thistle pub (under half a mile south-west) and Vauxhall Park (within half a mile north-west). Kennington has its own railway station: Vauxhall station. Well-known places in the area include Baynard's Castle (2.2 miles north) and Type Museum (0.5 miles south). The countryside around Kennington includes Bellenden Road Nature Garden and Ludgate Hill.
How to look after the new joints
After the cure time, these simple habits help:
- Avoid heavy scraping on the mastic joint
- Renew mastic before redecorating the windows
- Do not run silicone over sand mastic
- Have rotten timber repaired before new mastic goes in
Keep gutters and sills clear so water runs away from the surround. Constant wetting wears the mastic faster.
An open joint round the box lets weather through. The longer it’s left, the more the joint opens as more mastic falls out.
What happens if it’s left?
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic matches what was there and that can be important for listed homes. In a London flat, a failed joint rarely stays your problem alone: water can reach the neighbours below, and gaps in fire-rated joints affect the whole building.
The cost reflects the work involved, not guesswork. That is why we ask about the job first and agree the price before starting.
What you get with us
- Approved under the ARBOMaster scheme
- Neat joints and a tidy finish
- Trusted Arbo and Everbuild sealants
- 12-month guarantee on every job
Take a look at what affects the cost or our reviews.
Landlord and commercial work in Kennington
Mouldy or split sealant often shows up at the end of a tenancy, and it’s easy to sort out between tenants. Several properties can go on one quote.
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance.
Your questions about sand mastic in Kennington
Is Kennington in your area for sand mastic?
Yes. Our work covers London and the South East, and Kennington is part of that. Just call 0345 464 0079 or email us with a few details of the job.
Do you work for landlords with property near Vauxhall station?
Yes. We work for letting agents and landlords as well as householders, and several properties can be quoted together. You can call 0345 464 0079 or send us an email with the details for a clear quote.
Are you fully insured?
Yes. Full insurance covers our work, and we can confirm the details when we quote.
Where is Mr Mastic based?
We work from Crawley. We cover Kennington and the rest of Greater London, along with the rest of our area.
Is the work guaranteed?
There’s a 12-month guarantee on every job, sand mastic included.
Which is right for my windows, sand mastic or modern sealant?
It depends on the window. Period windows in stone or brick usually suit sand mastic, while modern frames normally get a flexible sealant.
How long will you be here?
That depends on the amount of work, but as a guide it takes anything from a few hours to a full day, depending on how many windows. We will tell you when we quote.
Do I have to be there?
It depends on the job. Inside work needs someone to give us access, while outside work can sometimes be arranged differently.
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes a few hours per window, depending on the condition of the joints. In Kennington, as in most of London, parking needs a little planning. It helps if you can point us to a visitor permit or a bay close to the door.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
How to prepare
- Let us know about parking restrictions
- Where the joints are inside, avoid wetting them before we arrive
- Plan for the work area to be out of bounds to pets and children
Get a quote
We don’t publish a price list. Instead, we give you a clear price for your job. To get started, call 0345 464 0079 or drop us an email.
Related advice
How we quote for sand mastic
Your quote is based on your job. We look at:
- How much old sealant there is and how hard it is to remove
- How many areas need sealing
- Any working-time requirements on site
- The product the joint needs
Some things make a job bigger or smaller: how much old sealant there is and how stubborn it is, any mould to treat, and whether the work is at height. We take all of that into account in your quote.
Helping us quote
What to tell us when you ask for a quote:
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it’s a home or a business
- If someone has resealed it before
- Any access issues, like height or stairs
For a quick quote, get us on the phone, or email us if that’s easier. Tell us about the joints that need doing and we will talk you through the work and give you a clear price.