Kent · England
Sand mastic for sash & case windows in Offham, Kent
Specialist sand mastic for Offham: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Gaps round a timber door in stone or brick
- Gaps where the frame meets the masonry
- Cement or filler used on old window joints that has cracked
About our sand mastic in Offham
Burnt sand mastic is a traditional material blends with stone and brick surrounds. It’s a good fit for period properties where a modern sealant bead would stand out. Common call-outs are for mastic dropping out of the joint and draughty sash windows at the surround, on timber door frames, brick reveals and sash and case windows.
In a village or hamlet like Offham, 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.
The work is covered for a year after we finish. If there’s a problem with it, please phone 0345 464 0079 or drop us an email.
- Location
- Offham (ME19)
- Wider area
- Kent
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Phone
- 0345 464 0079
- Updated
- 26 October 2026
Leave it or put it right?
Filling over old, loose mastic doesn’t last. Raking out and preparing the joint gives it a sound base so the new work lasts. Around Offham, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
Combining jobs into one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. We’ll give you a clear price for the lot.
Why Offham customers choose us
- Old sealant always removed completely
- Rated 4.9 stars on Google
- Approved under the ARBOMaster scheme
- Full insurance on every job
Take a look at how sealant jobs are priced or customer reviews.
DIY sealant or a professional job?
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.
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
How the visit works
We work through the job in order: protection first, then preparation, sealing and a tidy-up. For most jobs that takes anything from a few hours to a full day, depending on how many windows, and the area is left clean. Somewhere as small as Offham, access is often the only tricky part. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We start by checking each surround and agreeing the joints to renew.
- We rake out the old mastic and clean the joint.
- Large voids are packed out first, so the mastic isn’t too thick.
- We mix the sand mastic and apply it by hand, shaping it to the joint.
- The mastic is finished to sit tidily against the stone or brick.
Getting ready for the visit
- Where the joints are inside, avoid wetting them before we arrive
- Let us know about earlier repairs to the joints
- Tell us about access, such as stairs, a lift or high-level joints
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 give you a clear quote before we start.
Related advice
When it is not the sealant
We will not take on work that will not last, so here’s what sealant can’t put right:
- Sash cords, weights and draught-proofing of the sashes
- Rotten sashes, sills or window boxes (a joiner’s job)
- Cracked or broken glass
If you’re not sure, just phone 0345 464 0079 or drop us an email and we’ll give you a straight answer before booking.
What we seal
- Brick reveals
- Stone surrounds
- Period & listed homes
- Timber door frames
- Tenement windows
- Sash and case windows
What affects the cost of sand mastic
The quote reflects the job in front of us. We look at:
- The number and length of the joints
- How easy the joints are to reach
- Any working-time requirements on site
- The old material and how stubborn it is
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Helping us quote
You don’t need to know the technical terms. Just tell us:
- A few photos by email, if you can
- How many joints, rooms or windows are involved
- The type of property
- If someone has resealed it before
We quote each job on its own, so the first step is telling us about yours. Just call 0345 464 0079 or drop us an email with the details and send pictures if you have them.
Windows and doors in Offham
Historic houses like Old Soar Manor (about 3.1 miles south-west) are a reminder that the area around Offham 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. Rainfall in the South East is lower than in much of the UK, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast.
If you let a flat or house near West Malling station, any sash windows need sound mastic to keep draughts and rain out. For an older house near a landmark such as Church of St Michael, replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Schools such as Offham Primary School are buildings too, and larger buildings have plenty of frames, and the mastic around each one ages.
Offham is about 7 miles west of Maidstone, in Kent. Homes, rented property, offices and hotels in Offham is covered for sand mastic. The work is guaranteed for a year. Offham is one of 922 places in Kent where we work. We also work in London, about 25 miles from Offham.
Work in ME19 works the same way as everywhere else we cover. Whether your property is on Church Road, Pepingstraw Close and Teston Road or anywhere close by, we can help. If you’re just outside Offham, we cover Wrotham Heath (1 mile west), Comp (2 miles west), Kent Street (2 miles south), New Pound (2 miles south) and Herne Pound (2 miles south). Further out, we also cover Maidstone (7 miles east), Dartford (12 miles north-west), Sevenoaks (8 miles west), Royal Tunbridge Wells (12 miles south-west), Gravesend (10 miles north) and Tonbridge (8 miles south-west).
What’s near Offham
We work in homes and buildings around King's Arms Public House and Manor Park Country Park, among other places. For rail, the closest station is West Malling station, roughly 1.9 miles east. Other landmarks nearby include Leybourne Castle (2.2 miles north-east) and Maidstone Hospital (4.8 miles east).
FAQs for Offham
Do you cover smaller places like Offham?
Yes, Offham is covered. Our work covers London and the South East, and smaller places are part of that. Longer journeys are simply planned in advance.
Can you help a landlord with a rental near West Malling station?
Yes. We work for letting agents and landlords as well as homeowners. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we’ll send you a clear quote.
What do you put in the joint?
Quality sealants from brands including Arbo and Everbuild, picked for each joint. We explain the product when we quote.
Can sand mastic be painted?
Traditional guidance is not to paint over sand mastic. If you’re redecorating the window, ask us first and we will advise.
Does someone need to be in?
Access is agreed with you when the job is booked. For inside work, that normally means someone being in.
How long does sand mastic take to harden?
The surface skins quite quickly and it hardens fully over a longer time. Timing depends on the weather and the joint.
Where is Mr Mastic based?
We work from Crawley. Our applicators cover Offham, along with the rest of our area.
Will you leave a mess?
No. The area is protected while we work and cleaned up afterwards.
How the job changes by surface
Brick reveals
We rake out the old mastic and pack deep voids before the new mastic goes in.
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. Sand mastic seals the joint round it.
Nearby places to Offham
What else we do in Offham
How to look after the new joints
Once the sealant has cured, a few habits help it last:
- Avoid patching sand mastic with silicone
- Check with your local planning authority if your home is listed
- Avoid heavy scraping on the mastic joint
- Leave the new mastic unpainted
Keep paint scrapers and sanders off the mastic when redecorating. It can be damaged by heavy scraping.
Small cracks are a sign the mastic is ageing. It’s easier to renew it before it drops out.