Kent · England
New Ash Green Sand Mastic
Sand mastic for New Ash Green and the surrounding area: the right sealant, proper preparation and a neat finish. Call for a quick quote.
- Old cement repairs round a window that have failed
- Tired mastic found when preparing windows for paint
- Weathered mastic on the most exposed windows
Sand mastic in New Ash Green
Sand mastic doesn’t last for ever and gaps open up round the frame. Renewing it closes the gap so the surround looks right again. If you have cracked mastic round a front door frame and silicone on a period window that looks wrong, we can help.
Around New Ash Green, many homes face open ground, so their windows and doors take the full weather. That exposure dries out and cracks the mastic around frames and sills faster.
You’re covered for a year from the day we finish. If there’s a problem with it, please ring 0345 464 0079 or drop us an email.
- Where
- New Ash Green (DA3, TN15)
- Region
- Kent
- Cover
- 12 months on all our work
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Different surfaces, different methods
Brick reveals
We rake out the old mastic and pack deep voids before the new mastic goes in.
Period and listed homes
Materials matter on listed and conservation-area homes. Like-for-like sand mastic is normally favoured.
Can I do it myself?
The biggest DIY mistake is sealing over old sealant. Silicone doesn’t stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Some sealant jobs are within reach of a careful DIYer, such as a straightforward joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What we’re called out for in New Ash Green
Timber frames move with the seasons. That movement opens up the mastic joint little by little.
These are the problems we are asked about most:
- Patchy fillers round a sash window
- Modern sealant on a period surround
- Wind and rain getting in round a sash window
- Cracked mastic round a front door frame
For landlords with property near Longfield station, cracked sand mastic around sash windows lets in the draughts tenants complain about.
Before you book anyone
- Whether you can choose the colour
- How hidden problems are handled
- How long the guarantee is
- How long to leave it before use
Aftercare tips
Good habits help new joints last longer. A few tips:
- Sort the mastic before the decorators arrive
- Ask us before painting near the mastic
- Make sure water runs off the sill
- Have rotten timber repaired before new mastic goes in
Keep gutters and sills clear so water runs away from the surround. Water sitting against the mastic shortens its life.
Crumbling mastic lets rain into the joint. That water can reach the timber frame and the wall, so renewing it early is worth it.
What sand mastic looks like in New Ash Green
The South East is one of the drier parts of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Cobham College (about 4.3 miles east) nearby, there’s older building stock in the area around New Ash Green as well as newer homes. Where a home is older, older timber frames in brick or stone need a different approach from a modern uPVC window.
For an older house near a landmark such as Parish Church of Saint Peter and Saint Paul, frames set in older brick or stone need a sealant that suits the wall as well as the frame. For site and facilities teams at buildings such as New Ash Green Primary School, its window and door frames need their mastic kept sound, just like a home’s.
New Ash Green is about 5 miles south of Northfleet, in Kent. New Ash Green gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our area takes in 922 places across Kent, large and small. You can also see our page for London, about 20 miles away.
Here we cover the DA3 and TN15 postcode area for sand mastic. That includes homes and businesses on Church Road, Upper Street North and Upper Street South. Neighbouring places we cover for sand mastic include Ridley (1 mile south-east), Hartley (1 mile north), New Street (2 miles south-east), Hodsoll Street (2 miles south-east) and Longfield Hill (2 miles north-east). Further out, we also cover Maidstone (12 miles south-east), Dartford (6 miles north-west), Sevenoaks (8 miles south-west), Gravesend (5 miles north-east), Tonbridge (12 miles south) and Northfleet (5 miles north).
Landmarks near New Ash Green
Around New Ash Green, our work takes us to homes and buildings near The White Swan Public House, Longfield Academy and Rectory Meadow, among other places. The closest station to New Ash Green is Longfield station, roughly 2.1 miles north of the centre. Well-known places in the area include Eynsford Castle (4 miles west) and Darent Valley Hospital (5.2 miles north-west).
Common questions in New Ash Green
Is New Ash Green in your area for sand mastic?
Yes, New Ash Green is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or email us with a few details of the job, and we will send you a clear quote.
Can you help a landlord with a rental near Longfield station?
Yes. We work for landlords and agents as well as householders, and several properties can be quoted together. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Can old silicone round a sash window be swapped for sand mastic?
In most cases. The silicone is cut out and the joint cleaned before the sand mastic goes in.
Will it make a mess?
No. The area is protected while we work and cleaned up afterwards.
Will the old sealant be removed?
Yes. Sealing over the old bead is the commonest cause of early failure, and it’s something we never do.
Can you do several jobs on one visit?
Of course. Combining jobs makes good use of the visit, so mention them when you ask for a quote.
Can I paint the new mastic?
Traditional guidance is not to paint over sand mastic. Ask us before you decorate around it and we will talk you through it.
Can you work on commercial sites?
Yes. Hotels, offices and other businesses use us.
Landlords, agents and businesses in New Ash Green
Letting agents often deal with us directly. Send the address, what’s needed and the access arrangements and we will quote.
If you manage several properties in or around New Ash Green, jobs at different addresses can go on one quote. Send us the addresses and the work at each, and pictures by email help.
What happens on the day
Every visit runs the same way: we check the joints, mask and protect the surrounding surfaces, do the work and clear up. Most jobs take a few hours for a single window, longer for several. Somewhere as small as New Ash Green, access is often the only tricky part. For outside work, also let us know about exposed walls and any outbuildings involved.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic is not too thick.
- We point the joint with sand mastic by hand.
- The finish is dressed neatly.
How to prepare
- Where the joints are inside, avoid wetting them before we arrive
- Keep pets and children clear of the area while we work
- Clear items away from the joints we’re working on
Getting a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we will explain how we’d tackle it. When it suits you, call 0345 464 0079 or send us an email.
Related advice
What affects the cost of sand mastic
Your quote is based on your job. We take into account:
- Any mould that needs treating
- The type of sealant required
- The number and length of the joints
- Working hours on commercial sites
A few things move the cost up or down: the old material and how easily it comes out, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Helping us quote
A few details help us give you an accurate quote. When you get in contact, it helps to mention:
- Pictures of the joints, sent by email
- The rough size of the job
- What the problem is, such as mould, gaps, leaks or cracking
- Whether it has been sealed before
There’s no standard price list. Instead, your job gets its own clear quote. To arrange one, phone 0345 464 0079 or drop us an email.