Kent · England
Sand mastic for sash & case windows in Frinsted, Kent
Problem with your window and door surrounds in Frinsted? We remove the old material, prepare the joints and seal them properly.
- Old cement repairs round a window that have failed
- Open joints round the window box
- A silicone bead on a sash window that spoils the look
Different surfaces, different methods
Sash and case windows
On a sash window, the mastic joint shows on the outside so we finish it carefully.
Timber door frames
Door frames get knocked and soaked, so their mastic can fail sooner. It’s renewed by hand.
How we handle sand mastic in Frinsted
Sand mastic skins over fairly quickly, but it takes longer to harden fully. Traditional guidance is not to paint over it and we will advise if you are redecorating. We work on brick reveals, sash and case windows and period & listed homes, and people most often call us about gaps round a timber door in stone or brick and a silicone bead on a sash window that spoils the look.
Homes in small places like Frinsted often stand in the open, with little to shelter their windows from wind and rain. Exposed frames and sills lose their mastic sooner than sheltered ones.
There’s a 12-month guarantee on every job, large or small.
- Place
- Frinsted (ME9)
- Region
- Kent
- Guarantee
- 12 months on all our work
- Price
- Quoted before any work starts
- Call
- 0345 464 0079
- Updated
- 26 October 2026
What we are called out for in Frinsted
Some old mastic was never deep enough. Mastic that’s too thin cracks and drops out so we make sure the new mastic is the right thickness.
It’s worth asking for a quote if you see:
- Crumbling sand mastic round a window
- Window mastic to renew ahead of painting
- Failed mastic on an exposed elevation
- A silicone bead on a sash window that spoils the look
Letting a property close to Harrietsham station? Then any sash windows need sound mastic to keep draughts and rain out.
What your quote should include
- How the surfaces are prepared before sealing
- How the colour is chosen
- Is VAT in the price?
- Whether all the old sealant comes out first
Questions from Frinsted
Is Frinsted within the area you cover?
Yes. Frinsted 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 Harrietsham station?
Yes, rental work is part of what we do. Just ring 0345 464 0079 or email us and tell us about the property, and we will send you a clear quote.
Where is Mr Mastic based?
We work from Crawley. We cover Frinsted and the rest of Kent, along with the rest of our area.
Can you work on commercial sites?
Yes, regularly. We can plan bigger jobs in stages.
Is the work guaranteed?
There’s a 12-month guarantee on every job.
Can I do it myself?
That depends on the joint. High-level, external movement and fire-rated joints are professional jobs.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so the joint is cleaned back first.
How long will you be here?
Typically it takes a few hours for a single window, longer for several. Larger jobs naturally take longer, and we’ll say how long yours will take.
What sand mastic looks like in Frinsted
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 Leeds Castle (about 4 miles south-west) are a reminder that the area around Frinsted 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 is traditional sand mastic.
Homes close to St Giles include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. Managing a site like Milstead and Frinsted Church of England Primary School? Then larger buildings have plenty of frames, and the mastic around each one ages.
Frinsted is about 4 miles south of Sittingbourne, in Kent. Across the ME9 area, we cover sand mastic for homes and businesses. Our area takes in 922 places across Kent. For nearby work, see our Chelmsford page (33 miles or so).
All of ME9 is covered for sand mastic. Whether your property is on The Street, Bottom Pond Road and Dray's Field or anywhere close by, we can help. Nearby, we also carry out sand mastic in Milstead (1 mile north-east), Hollybushes (2 miles east), Bluetown (2 miles east), Wichling (2 miles east) and West Street (2 miles south-east). We also work in nearby towns such as Maidstone (8 miles west), Ashford (12 miles south-east), Sittingbourne (4 miles north), Whitstable (15 miles east), Faversham (8 miles east) and Minster (10 miles north-east).
Around Frinsted
Locally, jobs take us to homes and businesses close to The Blacksmith's Arms Public House, among other places. For rail, the closest station is Harrietsham station, roughly 3 miles south-west of the centre. Well-known places in the area include Leeds Castle (4 miles south-west) and Laundry Museum (3.8 miles south-west).
Landlords, agents and businesses in Frinsted
Letting agents often deal with us directly. Tell us the address, the job and how access works.
We also work for property managers and facilities teams in Frinsted and across Kent. We can quote a run of properties together.
Leave it or put it right?
Not every draught comes from the sashes themselves. Open mastic joints round the box can let air in and new mastic seals them. Where a wall is exposed, as many are in small places like Frinsted, wind-driven rain gets into any failed joint, and damp in older walls is slow to dry out.
What it costs depends on how much there is to do, how hard the old material is to remove and how easy the joints are to reach. We give a clear quote before we start, so you know where you stand.
Why book with us
- Any old sealant cut out fully, not covered over
- An ARBOMaster approved applicator
- 4.9 on Google from 180+ five-star reviews
- Sanitary silicone with an anti-fungal additive in wet areas
Take a look at how sealant jobs are priced and customer reviews.
How the visit works
We work through the job in order: protect, prepare, seal, tidy. Typically it takes a few hours per window, depending on the condition of the joints, and the area is left clean. Somewhere like Frinsted needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. We bring what the job needs, so it can be finished in one trip where possible.
- We check the window surrounds and agree which joints need renewing.
- The loose and crumbling mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The finish is dressed so it sits neatly against the stone or brick.
How to prepare
- Plan for the work area to be out of bounds to pets and children
- Move anything stored near the joints
- For indoor joints, keep the area dry beforehand if you can
Ask for a quote
For a quote, phone 0345 464 0079 or drop us an email and tell us where the job is and what the problem looks like. We will give you a clear quote before any work starts.
Advice
What affects the cost of sand mastic
Call for a quick quote. The main things that affect it are:
- Any mould that needs treating
- Access and height
- The old material and how stubborn it is
- Working hours on commercial sites
Homes and businesses are quoted the same way: the amount of work, the access and the products needed, plus any working-time requirements on site. Call for a quick quote and we will go through it with you.
Asking for a quote
Photos by email are helpful but not essential. Try to tell us:
- Photos by email, if that is easy
- If someone has resealed it before
- How many joints, rooms or windows are involved
- What the problem is, such as mould, gaps, leaks or cracking
For sand mastic in Frinsted, call 0345 464 0079 or drop us an email. A short description of the job and where it is helps us quote, and you will get a clear quote before we start.
DIY sealant or a professional job?
If you’re set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it fails, we can still redo it.
A DIY attempt does not rule out a professional job. We cut it out and start again.