Hertfordshire · England
Sand mastic for sash & case windows in Kimpton, Hertfordshire
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Kimpton, backed by a 12-month guarantee. Call for a quick quote.
- Weathered mastic on the most exposed windows
- Patchy fillers round a sash window
- Modern sealant on a period surround
What happens on the day
Before we leave, we go over the finished joints with you and explain the cure time. The work normally takes a few hours per window, depending on the condition of the joints, depending on how much there is to do. For a village or hamlet like Kimpton, the journey is planned in advance: let us know about lanes, gates and parking. We bring what the job needs, so it can be finished in one trip where possible.
- We look at the surrounds with you and agree the joints to renew.
- Old mastic and any loose material are raked out.
- Deep gaps are packed so the mastic sits at the right depth.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Getting ready for the visit
- Keep children and pets away from the work area
- Mention any sign-in or site rules at work premises
- Mention any leaks or damp you’ve noticed
Getting a quote
We do not publish a price list, because every job is different. Instead, your job gets its own clear quote. To arrange one, call 0345 464 0079 or send us an email.
Related advice
Sand mastic for homes and businesses in Kimpton
A silicone bead around a sash window can look out of place and does not suit the building. Sand mastic is the traditional choice and we can swap the silicone for it. We work on period & listed homes, tenement windows and timber door frames, and the jobs we see most are crumbling sand mastic round a window and draughts and rain around sash boxes.
Outdoor sealant needs dry, clean surfaces, so work on frames around Kimpton is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
All of our work is guaranteed for twelve months.
- Location
- Kimpton (SG4)
- Region
- Hertfordshire
- Guarantee
- One year on every job
- Quotes
- A clear price before work begins
- Call
- 0345 464 0079
- Page updated
- 26 October 2026
Sand mastic in Kimpton: local notes
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 Shaw's Corner (about 1.8 miles south-east) nearby, there’s older building stock in the area around Kimpton as well as newer homes. 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.
For an older house near a landmark such as Parish Church of St Peter and St Paul, the joint between an old wall and a newer frame is generally the first place rain gets in. If you let a flat or house near Harpenden station, older sash windows in a rental need their mastic kept sound to keep the weather out.
Kimpton is about 3 miles north-east of Harpenden, in Hertfordshire. We carry out sand mastic for homeowners, landlords and businesses in Kimpton and the surrounding area. Kimpton is one of 381 towns and villages in Hertfordshire where we work. We also work in London, around 26 miles away.
Jobs for sand mastic in SG4 works the same way as everywhere else we cover. That includes homes and businesses on High Street, Hampden and Wheelwrights. We also cover the places around Kimpton: Gustard Wood (2 miles south), Whitwell (2 miles north), Ayot St Lawrence (2 miles south-east), Codicote Bottom (2 miles east) and Codicote (3 miles east). We also work in nearby towns such as Watford (14 miles south), Hemel Hempstead (10 miles south-west), Stevenage (6 miles north-east), St Albans (7 miles south), Welwyn Garden City (6 miles south-east) and Harpenden (3 miles south-west).
Landmarks near Kimpton
Locally, jobs take us to homes and businesses close to The Boot pub. The closest station to Kimpton is Harpenden station, about 3.4 miles south-west of the centre. Other landmarks nearby include Harpenden Museum (3.6 miles south-west). For a walk, there’s Stocking Springs Wood.
DIY versus a professional finish
What a professional job adds is preparation and the right product. We take joints back to clean, dry surfaces, and the sealant is matched to the joint and its conditions, and the work is guaranteed for a year.
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
Kimpton: your questions answered
Do you work for landlords with property near Harpenden station?
Yes, we work for landlords and letting agents. You can ring 0345 464 0079 or drop us an email with the address and a few details, and we’ll give you a fixed price before any work starts.
Will you come out to Kimpton?
Yes. Kimpton is within the area we cover, which takes in towns, villages and rural addresses. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Can I add another job to the visit?
Yes, and it often makes sense. Combining jobs makes good use of the visit.
What exactly is sand mastic?
It’s sand mixed with a linseed-oil-based binder for the joint between timber frames and masonry.
What does sand mastic cost?
There’s no set price, as it 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.
Is it possible to take out silicone and use sand mastic instead?
Yes, we do this often. All the old silicone is removed first so the mastic can sit properly.
Which is right for my windows, sand mastic or modern sealant?
Sand mastic usually suits period timber windows best. On modern frames, we’d normally use a flexible sealant.
Can you work on commercial sites?
Yes. Commercial and hotel work is a large part of what we do. We can talk about working times when we quote.
What affects the quote in Kimpton
Some jobs are bigger than they look, and some smaller. What affects the quote:
- The size of the job
- Whether old sealant or filler has to be cut out
- How easy the joints are to reach
- How many areas need sealing
Leaving a failed joint normally makes the job bigger, not smaller, as water and mould keep getting in. If you are not sure whether it needs doing, ring 0345 464 0079 or email us for an honest opinion and a quote.
Helping us quote
To make quoting easier, please include:
- Access, such as stairs, a lift or height
- What the problem is, such as mould, gaps, leaks or cracking
- Where the property is
- Any previous sealing or DIY work
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, call 0345 464 0079 or email us.
What happens if it’s left?
An open joint round the frame lets weather in. Left, water can reach the timber and the wall so renewing it early protects the window. In a small place like Kimpton, homes can be exposed to wind and rain, which finds any gap, and damp in older walls is slow to dry out.
The cost depends on the amount of work, how much old material has to come out and how easy the joints are to reach. We give a clear quote before any work starts.
Why choose Mr Mastic in Kimpton
- We never seal over old sealant
- Over 20 years’ experience
- ARBOMaster approved applicator
- A 12-month guarantee on all work
What we are called out for in Kimpton
Rain on the window surround works into any crack and pushes it out. Exposed elevations generally fail first.
Signs it’s time to call us include:
- Window mastic to renew ahead of painting
- Old sand mastic that has cracked, crumbled or fallen out
- Modern sealant on a period surround
- Old cement repairs round a window that have failed
Managing a site like Kimpton Primary School? Then its window and door frames need their mastic kept sound, just like a home’s.
Before you book anyone
- What the quote includes, VAT included or not
- Whether they’re fully insured
- What preparation is included
- How long the guarantee is
What the job involves on each surface
Stone surrounds
Old stone surrounds are often uneven, so the gap is not the same all the way round. We shape it by hand to follow the stone.
Timber door frames
Sand mastic is used round timber door frames too. The method is the same as for windows.
How to look after the new joints
No joint lasts for ever, but care makes a real difference. Our tips:
- Avoid heavy scraping on the mastic joint
- Check the mastic when you check the paintwork
- Ask us before painting near the mastic
- Check with your local planning authority if your home is listed
Avoid sealing over the mastic with silicone. If anything cracks, get it looked at before trying a quick fix.
Gaps round a sash box let in draughts and rain. Left, the gap tends to get bigger as more mastic falls out.