Kent · England
Seal Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Seal, with a one-year guarantee on every job. Ask us for a quote.
- Open joints round the window box
- Draughts and rain around sash boxes
- Weathered mastic on the most exposed windows
When to call us in Seal
Paint, silicone or cement used over old mastic causes problems. They don’t move with the timber and we normally remove them.
If you can see any of these, it’s time to have the joints looked at:
- Draughty sash windows at the surround
- Gaps between timber frames and stone or brick
- Failed mastic on an exposed elevation
- Mastic round period door frames that has failed
In the older streets around Church of St Peter and St Paul, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
What to look for in a quote
- How long to leave it before use
- Is VAT in the price?
- Are they insured?
- How the joint is cleaned and prepared
Sand mastic for homes and businesses in Seal
We work across Seal renewing sand mastic on sash windows and doors. Each joint is raked out, prepared and pointed by hand for a neat, traditional finish. If you have old cement repairs round a window that have failed and open joints round the window box, we can help, whatever the surface.
Outdoor sealant needs dry, clean surfaces, so work on frames around Seal is planned for dry weather. Let us know about access to all the frames, upstairs ones included.
Every job is covered by our 12-month guarantee, wherever you are in Kent.
- Location
- Seal (TN15)
- Wider area
- Kent
- Guarantee
- 12 months on all our work
- Quotes
- A clear quote up front
- Telephone
- 0345 464 0079
- Page updated
- 26 October 2026
What else we do in Seal
Keeping the joints in good condition
Looking after new joints is easy:
- Check with your local planning authority if your home is listed
- Look over the window mastic once a year
- Ask a joiner to look at soft timber first
- Plan mastic work ahead of painting
Avoid sealing over the mastic with silicone. If you see a crack, ask us to take a look before trying a quick fix.
Small cracks are a sign the mastic is ageing. Renewing it then is simpler than waiting until it falls out.
Questions from Seal
Will you come out to Seal?
Yes, Seal is covered. We work across London and the South East, from towns to the smallest places. Longer journeys are simply planned in advance.
Can you do sand mastic in Seal?
Yes, Seal is within the area we cover. Our work covers London and the South East. Just ring 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear quote.
Is the work guaranteed?
You get our 12-month guarantee on every job.
Can you seal over the old sealant?
No. Fresh sealant does not stick to old sealant, and it traps any mould or water underneath. It all has to come out first.
Are you ARBOMaster approved?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
What should I tell you?
Let us know what needs doing and where. If we need more, we’ll ask.
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.
Are you insured?
Yes. We’re fully insured.
What sand mastic looks like in Seal
The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day. With historic houses such as Knole House (about 1.8 miles south) nearby, there’s older building stock in the area around Seal as well as newer homes. Where a home is older, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
If you look after a building such as Seal Church of England Voluntary Controlled Primary School, larger buildings have plenty of frames, and the mastic around each one ages. If you let a flat or house near Bat & Ball station, any sash windows need sound mastic to keep draughts and rain out.
Seal is about 2 miles north-east of Sevenoaks, in Kent. Whether you are in the middle of Seal or further out, we cover sand mastic for every kind of property, from flats and houses to offices and hotels. Across Kent, we cover 922 places, and Seal is one of them. London is on our list too, about 20 miles from Seal.
All of TN15 is covered for sand mastic, from the main roads to the quietest streets. That includes homes and businesses on High Street, Church Road and Jubilee Rise. Neighbouring places we cover for sand mastic include Greatness (1 mile west), Godden Green (1 mile south), Styants Bottom (2 miles east), Stone Street (2 miles south-east) and Bitchet Green (2 miles south-east). We also work in nearby towns such as Maidstone (13 miles east), Dartford (11 miles north), Royal Tunbridge Wells (11 miles south), Gravesend (12 miles north-east), Tonbridge (7 miles south) and Northfleet (11 miles north-east).
Local landmarks in Seal
In Seal, that means homes and buildings near Wildernesse School, Kemsing Down and The Five Bells Public House. The nearest railway station is Bat & Ball station, roughly 1.1 miles west. Well-known places in the area include Sevenoaks Hospital (1.1 miles west) and Sevenoaks Museum (1.7 miles south-west). Open spaces near Seal include Dryhill Nature Reserve.
Why act early in Seal
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic is the like-for-like choice and that can be important for listed homes. Where a wall is exposed, as many are in small places like Seal, wind-driven rain gets into any failed joint, and older walls, once damp, take a long time to dry.
Doing several joints on one visit usually makes better use of the time than several visits, so tell us about everything that needs sealing. We will give you a clear price for the lot.
Why Seal clients choose us
- Old sealant always removed completely
- Experience in homes, commercial sites and hotels
- Fully insured
- More than 20 years in sealant work
Take a look at how sealant jobs are priced or what customers say.
Landlords, agents and businesses in Seal
We work for landlords and agents as well as homeowners. Resealing between tenancies keeps a property looking cared for.
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance that we can handle for you.
What we cannot put right
To be straight with you, some problems need a different trade:
- Broken panes
- Sashes that rattle, stick or won’t open
- Rotten sashes, sills or window boxes (a joiner’s job)
If you’re not sure, just ring 0345 464 0079 or drop us an email and we’ll give you a straight answer before you book.
Where we work in Seal
- Sash and case windows
- Tenement windows
- Timber door frames
- Stone surrounds
- Brick reveals
- Period & listed homes
How we quote for sand mastic
For a quick quote, just ask. What matters most is:
- Access and height
- Whether old sealant or filler has to be cut out
- How many rooms, windows or areas are involved
- Whether there’s mould to deal with
What it costs depends on how much there is to do, how hard the old material is to remove and access to the work. You will have a clear quote before any work starts, so you know where you stand.
Asking for a quote
When you call or email, these details help:
- What’s wrong with the joints now
- Whether it’s a home or a business
- Any access issues, like height or stairs
- Photos by email, if that’s easy
It all starts with a short chat. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. Whenever you’re ready, call 0345 464 0079 or email us.
How the visit works
There is not much for you to do on the day. Show us the job and we will take it from there. The work itself takes a few hours for a single window, longer for several. Somewhere as small as Seal, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- First, we look at the surrounds with you and agree what needs doing.
- Old, loose mastic is raked out and the joint cleaned.
- Large voids are packed out first, so the mastic is not too thick.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The mastic is finished to sit tidily against the stone or brick.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- Tell us if parking is tricky
- Clear items away from the joints we are working on
Getting a quote
The more we know about the job, the more useful the quote. Let us know the location, the problem and roughly how many joints, and add photos by email if you can.