Kent · England
Sand mastic for sash & case windows in Borough Green, Kent
Sand mastic across Borough Green and nearby, with every bit of old sealant taken out first and a 12-month guarantee.
- Modern sealant on a period surround
- Patchy fillers round a sash window
- Mastic that needs renewing before redecorating
Sand mastic in Borough Green
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. We rake it out and renew it and tidies the surround. We’re often asked to deal with patchy fillers round a sash window and gaps round a timber door in stone or brick, across timber door frames, stone surrounds and sash and case windows.
Homes around Borough Green 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.
We stand behind the work with a one-year guarantee, so you’re covered after we’ve gone.
- Place
- Borough Green (TN15)
- Region
- Kent
- Guarantee
- 12 months on all our work
- Quote
- A clear quote up front
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Should I try it myself first?
Sealing over old silicone is the commonest DIY error. Silicone doesn’t stick to old silicone, so it peels away and traps moisture behind it. All the old material has to come out first.
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Also near Borough Green
More services for Borough Green
How we quote for sand mastic
There’s no set price list, because jobs vary so much. What we look at:
- The size of the job
- Any working-time requirements on site
- Whether the work is at height
- Any mould that needs treating
No two jobs are quite the same, so we quote each one individually. The number of joints, how easy they are to reach and the sealant needed all play a part.
What to tell us for a quote
Photos by email are helpful but not essential. Try to tell us:
- Whether it has been sealed before
- What the problem is, such as mould, gaps, leaks or cracking
- Photos by email, if that is easy
- How many joints, rooms or windows are involved
For sand mastic in Borough Green, ring 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you’ll get a clear quote before we start.
FAQs for Borough Green
Can you do sand mastic in Borough Green?
Yes, Borough Green is within the area we cover. Our work covers London and the South East. Just call 0345 464 0079 or send us an email with a few details of the job, and we’ll send you a clear quote.
Do you work for landlords with property near Borough Green & Wrotham station?
Yes. We work for landlords and agents as well as homeowners, and several properties can go on one quote. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear quote.
Is it possible to take out silicone and use sand mastic instead?
Usually, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
What guarantee comes with the work?
You get our 12-month guarantee on every job.
What is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It’s made with sand and a linseed-oil-based binder.
Are you fully insured?
Yes. We’re fully insured.
Can I paint the new mastic?
Traditional guidance is not to paint over sand mastic. Ask us before you decorate around it and we’ll talk you through it.
Is it OK to seal over old sealant?
No, it won’t last. It may look fine at first, but the new layer lifts away from the old one. Removing the old sealant completely is the only lasting way.
The process
We keep the work tidy and contained to the area we’re working on, so you can get on with your day. The job normally takes a few hours for a single window, longer for several. A visit to Borough Green 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.
- Large voids are packed out first, so the mastic isn’t 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
- Tell us about any previous sealing or DIY attempts
- Tell us about access, such as stairs, a lift or high-level joints
- For indoor joints, keep the area dry beforehand if you can
Get a quote
Want a quote for sand mastic? Please ring 0345 464 0079 or send us an email with a few details. We’ll explain what we’d do and send you a clear quote before any work starts.
Advice
Looking after it afterwards
How long the joints last depends on use and care. We suggest:
- Clear gutters so water does not pour onto the windows
- Go gently near the mastic when preparing windows
- Don’t paint over the new mastic
- Check with your local planning authority if your home is listed
Make sure water drains away from the window surround. Constant wetting wears the mastic faster.
Renewing mastic before redecorating saves doing it twice. Painting over failed mastic hides the problem for a while.
Windows and doors in Borough Green
Historic houses like Old Soar Manor (about 2.1 miles south) are a reminder that the area around Borough Green has older buildings as well as new. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. Compared with the north and west, the South East gets less rain, yet outdoor joints still have to be sealed dry, so jobs are booked with the weather in mind.
For an older house near a landmark such as The Church of the Good Shepherd, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. If you look after a building such as Borough Green Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Borough Green is about 5 miles east of Sevenoaks, in Kent. Homes, rented property, offices and hotels in Borough Green can book us for sand mastic, old or new, large or small. The work is guaranteed for a year. Our Kent coverage runs to 922 places, Borough Green among them. London is on our list too, about 23 miles from Borough Green.
Every address in TN15 is within our area for sand mastic, from the main roads to the quietest streets. Sand mastic is available to properties on Station Road, High Street and Hill View. Other places close to Borough Green include Basted (1 mile south), Platt (1 mile east), Crouch (1 mile south), Claygate Cross (1 mile south) and Comp (1 mile east). We also work in nearby towns such as Maidstone (10 miles east), Dartford (11 miles north), Sevenoaks (5 miles west), Royal Tunbridge Wells (11 miles south), Gravesend (10 miles north) and Tonbridge (7 miles south).
Around Borough Green
Locally, jobs take us to homes and businesses close to Wrotham School, Red Lion Public House and Wrotham School. Borough Green has its own railway station: Borough Green & Wrotham station. A little further out are Ightham Court (0.9 miles west) and Sevenoaks Hospital (4.9 miles west).
Surface by surface
Brick reveals
Gaps between frame and brick let in rain and draughts. New mastic seals the gap.
Period and listed homes
Many older homes were built with sand mastic round the windows. If your home is listed, ask your local planning authority about consent.
When to call us in Borough Green
Scraping and sanding before painting can loosen old mastic. Many people find it crumbling when they prepare the windows.
Keep an eye out for these signs:
- Window mastic to renew ahead of painting
- Cracked mastic round a front door frame
- Silicone on a period window that looks wrong
- Old sand mastic that has cracked, crumbled or fallen out
Letting a property close to Borough Green & Wrotham station? Then older sash windows in a rental need their mastic kept sound to keep the weather out.
Comparing quotes
- How much experience the applicator has
- Whether you can choose the colour
- How the surfaces are prepared before sealing
- How hidden problems are handled
Why act early in Borough Green
Not every draught comes from the sashes themselves. Gaps between the frame and the wall can be just as bad and new mastic seals them. Around Borough Green, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
Instead of a standard rate, we price the job in front of us: the amount of work, the old material and the access. The price is agreed before we begin.
Why choose Mr Mastic in Borough Green
- Old sealant always removed completely
- Homes, businesses and hotels
- Anti-fungal silicone where joints get wet
- Tidy, careful work
Take a look at what affects the cost or what customers say.