Hertfordshire · England
Sand mastic for sash & case windows in Highfield, Hertfordshire
Sand mastic across Highfield and nearby, with every bit of old sealant taken out first.
- Window mastic to renew ahead of painting
- Draughts and rain around sash boxes
- Cracked mastic round a front door frame
Sand mastic for homes and businesses in Highfield
Traditional burnt sand mastic that sits naturally against stone and brick. It’s a good fit for period properties, where modern sealant can look out of place. We work on period & listed homes, stone surrounds and tenement windows, and the jobs we see most are tired mastic found when preparing windows for paint and failed mastic on an exposed elevation.
In a smaller place like Highfield, some walls face open ground and catch the full force of the weather, so exposed windows and doors face the weather head on. That’s hard on the mastic around frames and sills.
You get a one-year guarantee, the same in Highfield as everywhere else we work.
- Location
- Highfield (HP2, HP1)
- Wider area
- Hertfordshire
- Cover
- 12 months on all our work
- Quotes
- Quoted before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Why act early in Highfield
Cement-based fillers and modern sealants don’t always suit a period surround. Sand mastic is the like-for-like choice, which can matter on listed and conservation-area homes. In an older home around Highfield, damp from a failed joint can get into timber and plaster, which is far harder to put right than the sealant itself.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. The price is agreed before we begin.
What you get with us
- Full insurance on every job
- 180+ five-star Google reviews
- Anti-fungal silicone where joints get wet
- 20+ years of sealant experience
FAQs for Highfield
Will you come out to Highfield?
Yes. Highfield 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.
Can you help a landlord with a rental near Hemel Hempstead station?
Yes, we work for letting agents and landlords. You can phone 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before work begins.
Are you insured?
Yes. Mr Mastic is fully insured, with over 20 years’ experience in sealant work.
Do you remove the old sealant?
Yes, always, and completely. New sealant won’t bond properly to old, so the joint is cleaned back first.
Can you seal over the old sealant?
No. New silicone won’t bond to old silicone, and it traps any mould or water underneath. We remove it all first.
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.
How long will you be here?
Typically it takes anything from a few hours to a full day, depending on how many windows. Bigger jobs take longer.
Do you do commercial work?
Yes. Hotels, offices and other businesses use us and we’re fully insured.
What the job involves on each surface
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair, so check who is responsible first.
Timber door frames
Sand mastic is used round timber door frames too. The method is the same as for windows.
Aftercare tips
To keep the joints looking good and working properly:
- Clear gutters so water does not pour onto the windows
- Do not run silicone over sand mastic
- Check the mastic when you check the paintwork
- Avoid heavy scraping on the mastic joint
Avoid painting over the new mastic, as traditional guidance advises. Ask us before any decorating around it.
Gaps round a sash box let in draughts and rain. The longer it’s left, the more the joint opens as more mastic falls out.
When something else is needed
A few problems are outside what sealant work can do:
- Decisions on consent for listed homes
- Sashes that need overhauling
- Rotten sashes, sills or window boxes (a joiner’s job)
If in doubt, phone 0345 464 0079 or send us an email and we will say what we think before booking.
Where we work in Highfield
- Timber door frames
- Stone surrounds
- Tenement windows
- Sash and case windows
- Brick reveals
- Period & listed homes
Highfield homes and the weather
With historic houses such as Batchwood Hall (about 4.4 miles east) nearby, there’s older building stock in the area around Highfield as well as newer homes. In older buildings, older timber frames in brick or stone need a different approach from a modern uPVC window. Hemel Hempstead, which Highfield is part of, is one of England’s post-war new towns. Many homes date from the post-war decades, and many will have had their original windows replaced. That mastic ages as well, and sills and frame heads are where leaks start.
Homes close to St Paul's include some older properties, and replacement windows fitted into old openings often leave uneven gaps that need backing and a flexible joint. Letting a property close to Hemel Hempstead station? Then any sash windows need sound mastic to keep draughts and rain out.
Highfield is about 1 mile north of Hemel Hempstead, in Hertfordshire. If you need sand mastic in Highfield, it’s easy to get a quote: please ring 0345 464 0079 or send us an email. We’re based in Crawley and cover Hertfordshire, Highfield included. We cover 381 towns and villages across Hertfordshire, large and small. London is on our list too, about 24 miles from Highfield.
Our applicators cover all of the HP2 and HP1 postcode area for sand mastic. Streets in the area include Juno Road, Great Road and Dione Road, and we cover them all. Highfield is on the A4147, which makes it straightforward to reach with everything needed for sand mastic. Close by, we work in Adeyfield (1 mile south-east), Hemel Hempstead (1 mile south), Piccotts End (1 mile north-west), Grovehill (1 mile south-west) and Woodhall Farm (1 mile south-west). We also work in nearby towns such as Watford (7 miles south), Stevenage (15 miles north-east), St Albans (6 miles east), Welwyn Garden City (12 miles east), Harpenden (6 miles north-east) and Hitchin (15 miles north-east).
What’s near Highfield
Locally, jobs take us to homes and businesses close to Gadebridge Park, The Old Bell pub and The Astley Cooper School. The nearest railway station is Hemel Hempstead station, roughly 2.1 miles south-west. Other landmarks nearby include Redbourn Museum (3.3 miles north-east) and Hemel Hempstead Hospital (1.1 miles south-west). The countryside around Highfield includes Verulamium Lake and Long Deans.
The process
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. A visit to Highfield 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.
- We start by checking each surround and agreeing the joints to renew.
- Old, loose mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- We dress the surface so it sits neatly against the masonry.
How to prepare
- For business premises, tell us about site rules or sign-in
- Plan for the work area to be out of bounds to pets and children
- Tell us about any water getting in
Ask for a quote
For a quote, call 0345 464 0079 or send us an email with the location and a short description of the problem. We will give you a clear quote before any work starts.
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Landlords, agents and businesses in Highfield
Whether it’s one flat or a portfolio, the work is the same standard: the old material taken out, careful preparation and a 12-month guarantee.
For anyone letting property in or around Highfield, several properties can be quoted together. Just tell us the addresses and what each one needs, and pictures by email help.
Do you need sand mastic in Highfield?
Over the years, sand mastic weathers. It hardens, cracks and starts to come away from the frame or the masonry.
Most people get in touch after spotting something like this:
- Draughty sash windows at the surround
- Failed mastic on an exposed elevation
- Mastic that needs renewing before redecorating
- Crumbling sand mastic round a window
For site and facilities teams at buildings such as Yewtree Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
What your quote should include
- Whether they’re fully insured
- What guarantee comes with the work
- Who does the work, and how experienced they are
- Whether all the old sealant comes out first