Kent · England
Sand mastic for sash & case windows in Southfleet, Kent
Our applicators work in Southfleet on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old material cut out, joints cleaned and sealed neatly.
- Open joints round the window box
- Patchy fillers round a sash window
- Mastic worn away on windows facing the weather
About our sand mastic in Southfleet
We work across Southfleet renewing sand mastic on sash windows and doors. Every joint is cleaned out and filled by hand, finished to suit the masonry. Typical jobs include wind and rain getting in round a sash window and old cement repairs round a window that have failed, across period & listed homes, timber door frames and brick reveals.
Around Southfleet, many homes face open ground, so their windows and doors take the full weather. Exposed frames and sills lose their mastic sooner than sheltered ones.
Big or small, you get the same 12-month guarantee in Southfleet and across Kent.
- Location
- Southfleet (DA13)
- Region
- Kent
- Guarantee
- One year on every job
- Price
- A clear price before we start
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
When something else is needed
Sealant is not the answer to every problem, and we will tell you before work begins. Sealant won’t put right:
- Sash cords, weights and draught-proofing of the sashes
- Decayed frames that need repair
- Crumbling stone or brickwork round the window
Not sure which it is? You can phone 0345 464 0079 or drop us an email and we’ll tell you honestly.
Joints and surfaces we work on
- Stone surrounds
- Tenement windows
- Sash and case windows
- Brick reveals
- Timber door frames
- Period & listed homes
Questions from Southfleet
Can you help a landlord with a rental near Longfield station?
Yes, we work for landlords and agents. You can ring 0345 464 0079 or email us with the address and a few details, and we’ll give you a fixed price before we start.
Is Southfleet in your area for sand mastic?
Yes. We work across London and the South East, and Southfleet is part of that. You can ring 0345 464 0079 or send us an email and tell us what needs doing.
When will the new mastic be hard?
It forms a skin fairly soon and it hardens fully over a longer time. The weather and joint depth both affect it.
Is there any odour?
That depends on the sealant. Some products have a noticeable smell, others very little.
Should I try DIY first?
Sometimes. Preparation is everything: all the old sealant out, and a clean, dry joint. If it does not work out, we can redo it.
Do you offer different sealant colours?
Generally, yes. White, clear and grey are common, and other colours are available for many products, and we agree the colour with you before any work starts.
Should I check with the council before work on a listed or conservation-area home?
Speak to your local planning authority before work starts. Sand mastic is often favoured as like for like, but they decide.
Can you seal over the old sealant?
No, because it fails. We remove every bit of old sealant first.
How the job changes by surface
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair, so check who is responsible first.
Sash and case windows
Sash windows are where we do most sand mastic work. Each joint round the box is raked out and renewed.
Signs you need sand mastic in Southfleet
Water gets into small cracks in the mastic and loosens it further. Exposed elevations usually fail first.
The problems people normally mention when they call include:
- Tired mastic found when preparing windows for paint
- Gaps round a timber door in stone or brick
- Mastic worn away on windows facing the weather
- Silicone on a period window that looks wrong
If you live in an older home near Church of St Nicholas, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
What your quote should include
- Is VAT in the price?
- How the joint is cleaned and prepared
- Is the old sealant removed completely?
- When the joint can take water or movement
Nearby places to Southfleet
Also in Southfleet
What we do, step by step
You do not need to clear the whole room or building, 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 for a typical job. In a small place like Southfleet, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- First we agree which joints need doing.
- We remove the old, loose mastic.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- We dress the finish so it sits neatly against the masonry.
Preparing for the visit
- Mention any leaks or damp you’ve noticed
- Move anything stored near the joints
- Let us know about parking restrictions
How to get 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.
Advice
Why deal with it now?
If you’re redecorating, renew the mastic first. Painting over failed mastic does not seal it and traditional guidance is to leave the new mastic unpainted. Around Southfleet, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
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.
Why us?
- A 12-month guarantee on all work
- Sanitary silicone with an anti-fungal additive in wet areas
- Full insurance on every job
- Neat joints and a tidy finish
Take a look at our cost guide and our reviews.
Quotes for sand mastic in Southfleet
We do not publish a price list. The quote depends on:
- The product the joint needs
- Working hours on commercial sites
- The old material and how stubborn it is
- The number and length of the joints
There are no prices on our website, because each job is priced on what it involves. For a quick quote, please call 0345 464 0079 or drop us an email.
What we need to know
There’s no need for technical detail. Just tell us:
- The type of property
- Any previous sealing or DIY work
- How many joints, rooms or windows are involved
- A few photos by email, if you can
We quote each job on its own. Just phone 0345 464 0079 or drop us an email with the details.
Sand mastic in Southfleet: local notes
London and the South East are among the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. Historic houses like Cobham College (about 3.6 miles south-east) are a reminder that the area around Southfleet 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’s traditional sand mastic.
Letting a property close to Longfield station? Then older sash windows in a rental need their mastic kept sound to keep the weather out. Managing a site like Sedley's Church of England Voluntary Aided Primary School? Then the mastic around its windows and doors needs looking after like any other building’s.
Southfleet is about 2 miles south-west of Northfleet, in Kent. Southfleet gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a 12-month guarantee. Our area takes in 922 places across Kent, from the larger towns to small villages. You can also see our page for London, roughly 19 miles from Southfleet.
All of DA13 is covered for sand mastic. You will find streets such as Red Street, Gloxinia Road and Brakefield Road, all of which we cover. If you are just outside Southfleet, we cover Hook Green (1 mile south-west), Northfleet Green (1 mile east), Betsham (1 mile north-west), Painters Ash (1 mile north-east) and Springhead (1 mile north). Within a short drive, we also cover Maidstone (13 miles south-east), Dartford (5 miles north-west), Sevenoaks (11 miles south-west), Gravesend (3 miles north-east), Tonbridge (15 miles south) and Swanley (7 miles west).
Near you in Southfleet
We work in homes and buildings around Northfleet School for Girls, Black Lion pub and Longfield Chalk Bank, among other places. The closest station to Southfleet is Longfield station, roughly 1.5 miles south-west of the centre. Nearby you’ll also find Gravesham Community Hospital (2.7 miles north-east) and Bluewater (2.9 miles north-west). Not far away are Sawyers Lake.
Work for landlords, hotels and businesses
Landlords and letting agents in Southfleet can book us as well as householders. Resealing between tenancies is a simple way to keep a property in good order before the next move-in.
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we will give you a quote.