Kent · England
Sand mastic for sash & case windows in Wilmington, Kent
Sand mastic across Wilmington and nearby, with every bit of old sealant taken out first and a one-year guarantee.
- Patchy fillers round a sash window
- Silicone on a period window that looks wrong
- Cracked mastic round a front door frame
What the job involves on each surface
Sash and case windows
Sash windows are where we do most sand mastic work. We renew the mastic round each box.
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
About our sand mastic in Wilmington
A silicone bead around a sash window can look out of place and is not always the right material. Sand mastic gives a finish that matches the age of the house and we can swap the silicone for it. Typical jobs include mastic worn away on windows facing the weather and a silicone bead on a sash window that spoils the look, across timber door frames, sash and case windows and brick reveals.
In a village or hamlet like Wilmington, older cottages and farmhouses often have timber windows set in stone or brick. Older buildings like these don’t always suit modern silicone, so the sealant has to be chosen to suit the building.
All of our work is guaranteed for twelve months.
- Location
- Wilmington (DA2, DA5, DA1)
- Region
- Kent
- Guarantee
- 12 months on all our work
- Quotes
- A clear price before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
Towns and villages near Wilmington
More services for Wilmington
Sand mastic in Wilmington: local notes
London and the South East are among 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 Hall Place and Gardens (about 1.7 miles north-west) nearby, there’s older building stock in the area around Wilmington as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window.
Schools such as Wilmington Grammar School for Girls are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages. In the older streets around St Barnabas, frames set in older brick or stone need a sealant that suits the wall as well as the frame. Rented homes near Crayford station change hands often, and cracked sand mastic around sash windows lets in the draughts tenants complain about.
Wilmington is about 2 miles south-west of Dartford, in Kent. Homes, rented property, offices and hotels in Wilmington can book us for sand mastic, old or new, large or small. The work is guaranteed for a year. Across Kent, we cover 922 places, Wilmington among them. You can also see our page for London, about 13 miles away.
Every address in DA2, DA5 and DA1 is within our area for sand mastic, from the main roads to the quietest streets. You’ll find streets such as Common Lane, Parsons Lane and Oakfield Lane, all of which we cover. Being close to the A2, Wilmington is easy for our applicators to reach for sand mastic. We also cover the places around Wilmington: Bowmans (1 mile north), Joyden's Wood (1 mile west), Puddledock (1 mile south-west), Coldblow (1 mile north-west) and Crayford (1 mile north). Further out, we also cover Sevenoaks (10 miles south), Gravesend (8 miles east), Northfleet (7 miles east), Kings Hill (14 miles south-east), Swanscombe (5 miles east) and Windmill Hill (8 miles east).
Around Wilmington
In Wilmington, that means homes and buildings near Dartford Heath, The Plough pub and Wilmington Primary School. Wilmington’s nearest station is Crayford station, about 1.3 miles north. Nearby you will also find Stone Castle (4 miles east) and West Hill Hospital (1.4 miles north-east). Green spaces nearby include Wansunt Pit.
What we do, step by step
There’s no need to move everything out before we come, just the space around the work. We protect the rest, and the job takes anything from a few hours to a full day, depending on how many windows in most cases. Somewhere like Wilmington needs a little journey planning: let us know about lanes, gates and parking. Everything for the job comes with us, so a second trip is avoided where possible.
- We look at the surrounds with you and agree the joints to renew.
- We remove the old, loose mastic.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Getting ready for the visit
- Plan for the work area to be out of bounds to pets and children
- Mention any leaks or damp you’ve noticed
- Mention if the joints have been sealed before
How to get a quote
We don’t publish a price list, as no two jobs are quite the same. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or send us an email.
Read more
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Make sure water runs off the sill
- Take care around the mastic when scraping paint
- Ask us before painting near the mastic
- Sort the mastic before the decorators arrive
Keep gutters and sills clear so water runs away from the surround. Water sitting against the mastic shortens its life.
Once mastic starts to crumble, rain gets in. It can soak into the frame and the surrounding masonry, so renewing it early is worth it.
When it is not the sealant
We’ll always be straight with you, so here’s what new sealant will not do:
- Broken panes
- Damaged stone surrounds
- Planning or listed building consent (your local planning authority decides)
If in doubt, ring 0345 464 0079 or email us and we will say what we think before booking.
Joints and surfaces we work on
- Brick reveals
- Sash and case windows
- Period & listed homes
- Timber door frames
- Stone surrounds
- Tenement windows
Wilmington questions
Do you cover Wilmington for sand mastic?
Yes. Our work covers London and the South East, and Wilmington is part of that. Just phone 0345 464 0079 or send us an email with a few details of the job, and we’ll give you a clear quote.
Can you help a landlord with a rental near Crayford station?
Yes. We work for landlords and letting agents as well as householders, and several properties can be quoted together. Just ring 0345 464 0079 or email us with the address and what needs doing, and we’ll give you a clear quote.
Is consent needed for window work on a listed home?
It’s best to ask your local planning authority first. Like-for-like sand mastic is often the preferred finish but the decision is theirs.
How long will you be here?
Typically it takes a few hours per window, depending on the condition of the joints. Larger jobs naturally take longer, and we’ll say how long yours will take.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice, and we’ll explain our choice.
Is the work guaranteed?
There’s a 12-month guarantee on every job.
Do I have to be there?
If the work is inside, we need someone to let us in. After that, you can carry on with your day.
Do you remove the old sealant?
Yes, always, and completely. New sealant won’t bond properly to old, so the joint is cleaned back first.
DIY versus a professional finish
Some sealant jobs are within reach of a careful DIYer, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
What affects the quote in Wilmington
For a quick quote, just ask. The main things that affect it are:
- When we can work, for business premises
- The product the joint needs
- Access and height
- Mould in or behind the old joints
Instead of a standard rate, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
Asking for a quote
When you contact us, these details help:
- The address or postcode of the job
- A few pictures by email, if you can
- Any previous sealing or DIY work
- How many joints, rooms or windows are involved
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and email pictures if that is easy.
Work for landlords, hotels and businesses
We work for letting agents and landlords as well as householders. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
Housing providers, facilities teams and property managers book us too. Several sites can be quoted together, and we are fully insured for the work.