Kent · England
Sand mastic for sash & case windows in Swanley, Kent
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for householders, landlords and businesses in Swanley. ARBOMaster approved applicators, fully insured, with a 12-month guarantee.
- Cement or filler used on old window joints that has cracked
- Window mastic to renew ahead of painting
- Failed mastic on an exposed elevation
Why act early in Swanley
Gaps round a sash window let in rain and draughts. Left, water can reach the timber and the wall, so dealing with it now protects both. Around Swanley, water from a failed joint in an older home can soak into timber and plaster, and that’s a much bigger job than renewing the sealant.
What you pay reflects the work, not a rough estimate. That is why we ask about the job first.
Why book with us
- Anti-fungal silicone where joints get wet
- Tidy, careful work
- Quality sealants from Arbo and Everbuild
- Old sealant always removed completely
Take a look at what affects the cost or customer reviews.
How we handle sand mastic in Swanley
Fresh sand mastic forms a skin quite soon but full hardening takes longer. Traditional guidance is not to paint over it and we’ll advise if you are redecorating. Common call-outs are for crumbling sand mastic round a window and tired mastic found when preparing windows for paint, on stone surrounds, brick reveals and period & listed homes.
Homes around Swanley range from older properties to newer houses, and their windows range just as widely. Each frame material needs the right sealant against the right wall.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we will put it right.
- Where
- Swanley (BR8)
- Region
- Kent
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
How the job changes by surface
Tenement and terrace windows
Windows above ground floor need the right access. Let us know the floor and we will confirm access.
Stone surrounds
Stone openings are rarely perfectly straight, so the joint varies in width. We shape it by hand to follow the stone.
Nearby places to Swanley
What else we do in Swanley
Honest limits
A few problems are outside what sealant work can do:
- Decayed frames that need repair
- Planning or listed building consent (your local planning authority decides)
- Broken panes
Not sure which it is? You can call 0345 464 0079 or drop us an email and we will tell you honestly.
Where we work in Swanley
- Brick reveals
- Stone surrounds
- Timber door frames
- Sash and case windows
- Period & listed homes
- Tenement windows
Common questions in Swanley
Is Swanley within the area you cover?
Yes. Swanley is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Let us know about access, parking and anything unusual about getting there when you book.
Can you help a landlord with a rental near Swanley station?
Yes, we work for landlords and agents. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we will give you a fixed price before we start.
Are you an approved applicator?
Yes. We are approved under the ARBOMaster scheme, which is run for the Arbo sealant brand.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Is there any odour?
There can be a smell while the sealant cures. Opening a window helps.
What does sand mastic cost?
We don’t publish prices, because the cost depends on the job: how much there is, what’s there now, how we reach it and what it needs. We agree the price before any work begins.
What sealant do you use?
Each joint gets the product that suits it. Where it moves, gets wet or faces the weather makes a difference, and we will tell you what we are using.
Do you guarantee sand mastic work?
All our work has a 12-month guarantee, and we are fully insured.
The process
Most of a good job is in the preparation, so that is where we spend the time. Every joint is cleaned and dried before new material goes in. In total, it generally takes a few hours per window, depending on the condition of the joints. A visit to Swanley is planned like any other: the time, the access and where to park are agreed in advance. Outdoor jobs depend on a dry day, since sealant needs a dry surface.
- First, we look at the surrounds with you and agree what needs doing.
- We rake out the old mastic and clean the joint.
- We pack any deep gaps so the mastic sits at the right depth.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The finish is dressed so it sits neatly against the stone or brick.
Preparing for the visit
- Mention any tricky access
- On commercial sites, let us know about site rules
- Move anything stored near the joints
Getting a quote
We do not publish a price list, as no two jobs are quite the same. Instead, we give you a clear quote for your job. To arrange one, ring 0345 464 0079 or email us.
Advice
DIY sealant or a professional job?
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and getting the depth right matters as much as the look.
The biggest DIY mistake is sealing over old sealant. Silicone does not stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
When to call us in Swanley
Previous repairs in cement or silicone often trap water or crack away. They don’t suit the joint and we normally remove them.
If you can see any of these, it’s time to have the joints looked at:
- Open joints round the window box
- Window mastic to renew ahead of painting
- Cement or filler used on old window joints that has cracked
- Failed mastic on an exposed elevation
If you live in an older home near St Mary the Virgin, the joint between an old wall and a newer frame is generally the first place rain gets in.
What to look for in a quote
- How hidden problems are handled
- Which sealant they’ll use, and why
- How the colour is chosen
- Is the old sealant removed completely?
How we quote for sand mastic
Jobs vary more than people expect. The main factors:
- The type of sealant required
- Whether the work is at height
- Whether there’s mould to deal with
- The old material and how stubborn it is
No two jobs are quite the same, so each one gets its own quote. Size, access and the product the joint needs all make a difference.
Helping us quote
Before you ask for a quote, have a think about:
- How we’d reach the joints
- What’s wrong with the joints now
- Where the job is, and your postcode
- If someone has resealed it before
Want a quote for sand mastic? Please phone 0345 464 0079 or send us an email and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
What sand mastic looks like in Swanley
London and the South East are among the drier parts of the UK, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind. With historic houses such as Lullingstone Castle (about 2.9 miles south) nearby, there’s older building stock in the area around Swanley as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
For landlords with property near Swanley station, any sash windows need sound mastic to keep draughts and rain out. Managing a site like St Bartholomew's Catholic Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Swanley is about 3 miles east of Orpington, in Kent. If you need sand mastic in Swanley, please ring 0345 464 0079 or send us an email for a quick quote. We cover Kent from our Crawley base, Swanley included. Swanley is one of 922 places in Kent where we work. London is on our list too, about 14 miles from Swanley.
Postcode districts we cover here for sand mastic: BR8. Whether your property is on London Road, Station Road and High Street or anywhere close by, we can help. Swanley sits on or near the A20 and B258, so getting to you is simple. Other places close to Swanley include Crockenhill (1 mile south-west), Kevington (2 miles south-west), Derry Downs (3 miles west), St Mary Cray (3 miles west) and St Paul's Cray (3 miles west). Within a short drive, we also cover Dartford (4 miles north-east), Sevenoaks (8 miles south), Gravesend (9 miles east), Tonbridge (14 miles south), Northfleet (8 miles east) and Kings Hill (13 miles south-east).
Near you in Swanley
In Swanley, that means homes and buildings near Orchards Academy and the streets around them. There’s a railway station in Swanley itself: Swanley station. A little further out are London Borough of Bromley Museum (3.2 miles south-west) and Queen Mary's Hospital (3.4 miles north-west). Open spaces near Swanley include The Warren and Summer Hill.