Hertfordshire · England
Sand mastic for sash & case windows in Shenley, Hertfordshire
Sand mastic for Shenley, by sealant specialists with 20+ years’ experience. 180+ five-star Google reviews and a 4.9 rating.
- Tired mastic found when preparing windows for paint
- Modern sealant on a period surround
- Old sand mastic that has cracked, crumbled or fallen out
Aftercare tips
Looking after new joints is easy, and it makes a real difference:
- Inspect the joints round the windows every year or so
- Leave the new mastic unpainted
- Renew mastic before redecorating the windows
- Take care around the mastic when scraping paint
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.
Sand mastic for homes and businesses in Shenley
Sand mastic suits most period window surrounds. Newer frames generally get a flexible sealant instead, and we will talk through which suits your home. If you are dealing with mastic that needs renewing before redecorating and mastic dropping out of the joint, we can put it right.
Around Shenley, conservatories, garden rooms and patio doors are often part of the house. Those joints need the same attention as the main windows, and any older timber or sash windows need a sealant that suits them.
Whatever the size of the job, it’s backed by our one-year guarantee in Shenley and across Hertfordshire.
- Location
- Shenley (WD7)
- Region
- Hertfordshire
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Phone
- 0345 464 0079
- Page updated
- 26 October 2026
Do you need sand mastic in Shenley?
Over the years, sand mastic weathers. It hardens, cracks and starts to come away on the stone or timber.
These are the problems we are asked about most:
- A silicone bead on a sash window that spoils the look
- Gaps round a timber door in stone or brick
- Wind and rain getting in round a sash window
- Old cement repairs round a window that have failed
Homes close to Church of St Martin include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Comparing quotes
- Whether all the old sealant comes out first
- Is VAT in the price?
- What guarantee comes with the work
- How the surfaces are prepared before sealing
What affects the cost of sand mastic
We don’t publish a price list, because no two jobs are the same. What we look at:
- Whether old sealant or filler has to be cut out
- Whether there’s mould to deal with
- Working hours on commercial sites
- Access and height
Combining jobs into one visit generally makes better use of the time than several visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
Asking for a quote
When you contact us, these details help:
- Roughly how big the job is
- Whether it’s a home or a business
- Where the property is
- Access, such as stairs, a lift or height
A good description makes for an accurate quote. Tell us where the job is, what’s wrong and how much there is, and add photos by email if you can.
Leave it or put it right?
Before painting the windows, it pays to renew the mastic. Painting over failed mastic doesn’t seal it and traditional guidance is to leave the new mastic unpainted. Around Shenley, water from a failed joint in an older home can soak into timber and plaster, and that is a much bigger job than renewing the sealant.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all play a part.
Why us?
- We’re fully insured
- 180+ five-star Google reviews
- Domestic, commercial and hotel work
- ARBOMaster approved applicator
Read what affects the cost or customer reviews.
Different surfaces, different methods
Brick reveals
Sand mastic is also used where timber frames meet brick. It suits older brickwork.
Period and listed homes
Materials matter on listed and conservation-area homes. Sand mastic is often the preferred finish.
What happens on the day
Most of a good job is in the preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours for a single window, longer for several. In a smaller place like Shenley, parking is seldom the issue; lanes, gates and long drives are worth mentioning. For outside work, side access and the height of the joints help us plan.
- Each surround is checked first.
- The joint is raked out and cleaned.
- We fill deep gaps so the new mastic isn’t too thick.
- New sand mastic is applied and shaped by hand.
- The finish is dressed neatly.
Getting ready for the visit
- Tell us about access, such as stairs, a lift or high-level joints
- Keep pets and children clear of the area while we work
- On commercial sites, let us know about site rules
Getting a quote
For a quote, phone 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We’ll send you a clear quote before any work starts.
Related advice
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Shenley questions
Can you help a landlord with a rental near Radlett station?
Yes, rental work is part of what we do. Just phone 0345 464 0079 or send us an email and tell us about the property, and we will send you a clear quote.
Will you come out to Shenley?
Yes. Shenley is within the area we cover, which takes in towns, villages and rural addresses. Our work covers London and the South East. Just mention lanes, gates or anything else about the route when you book.
What do you need from me for a quote?
A short description and the location, with pictures by email if possible. We’ll ask anything else we need to know.
Where is Mr Mastic based?
Our base is Crawley. Our area covers South East England, London and Scotland.
What is sand mastic?
Sand mastic is a traditional material for pointing round windows and doors. It combines sand with a linseed-oil-based binder.
What guarantee comes with the work?
Our 12-month guarantee covers every job, sand mastic included.
Is there any odour?
It depends on the product. Some products have a noticeable smell, others very little, and any smell fades as they cure.
Should I try DIY first?
It depends on the job. Work at height, movement joints, fire-rated gaps and large areas are best left to a professional.
Sand mastic in Shenley: local notes
Compared with the north and west, the South East gets less rain, but outside sealant still needs a dry, clean surface, so outdoor work is planned around the forecast. With historic houses such as Wyllyotts Manor (about 4.1 miles east) nearby, there’s older building stock in the area around Shenley as well as newer homes. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that is traditional sand mastic.
If you let a flat or house near Radlett station, any sash windows need sound mastic to keep draughts and rain out. For site and facilities teams at buildings such as Shenley Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Shenley is about 2 miles north of Borehamwood, in Hertfordshire. Every kind of property in Shenley is covered for sand mastic, old or new, large or small. The work is guaranteed for a year. Our Hertfordshire coverage runs to 381 places, and Shenley is one of them. London is on our list too, about 16 miles from Shenley.
Here we cover the WD7 postcode area for sand mastic. That includes homes and businesses on London Road, Southerton Way and Juniper Gardens and the roads around them. You will find Shenley on the B5378, which makes it straightforward to reach with everything needed for sand mastic. Neighbouring places we cover for sand mastic include Green Street (1 mile south-east), Ridge (2 miles east), Well End (2 miles south-east), Borehamwood (2 miles south) and South Mimms (2 miles east). Larger places within reach include Watford (5 miles south-west), Hemel Hempstead (8 miles north-west), St Albans (4 miles north-west), Welwyn Garden City (8 miles north-east), Harpenden (9 miles north) and Hoddesdon (12 miles east).
Around Shenley
Locally, jobs take us to homes and businesses close to Manor Lodge School, Hertswood Academy and The Black Lion pub, among other places. The nearest railway station is Radlett station, about 1.4 miles south-west of the centre. A little further out are Radlett and District Museum (1.5 miles south-west) and Shenley Hospital (less than half a mile west). For a walk, there’s Verulamium Lake and Broad Colney Lakes.
What we cannot put right
A few problems are outside what sealant work can do:
- Crumbling stone or brickwork round the window
- Timber that has rotted
- Sashes that need overhauling
If in doubt, ring 0345 464 0079 or send us an email and we will say what we think.
Where we work in Shenley
- Stone surrounds
- Timber door frames
- Sash and case windows
- Period & listed homes
- Brick reveals
- Tenement windows