Hertfordshire · England
Holwellbury Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Holwellbury, backed by a 12-month guarantee. Ask us for a quote.
- Gaps round a timber door in stone or brick
- Modern sealant on a period surround
- Mastic dropping out of the joint
Sand mastic in Holwellbury
Traditional burnt sand mastic that sits naturally against stone and brick. It suits period and listed homes, where modern sealant can look out of place. We work on timber door frames, brick reveals and sash and case windows, and the jobs we see most are cement or filler used on old window joints that has cracked and cracked mastic round a front door frame.
In a village or hamlet like Holwellbury, older cottages and farmhouses often have timber windows set in stone or brick. Not every older frame suits a modern silicone bead, and sometimes a traditional sand mastic is the better choice.
Each job carries a 12-month guarantee, large or small.
- Place
- Holwellbury (SG5)
- Region
- Hertfordshire
- Guarantee
- A year, on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Updated
- 26 October 2026
What we do, step by step
We work through the job in order: protect, prepare, seal, tidy. For most jobs that takes a few hours for a single window, longer for several, and the area is left clean. Somewhere like Holwellbury needs a little journey planning: 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.
- We pack any deep voids first.
- The sand mastic is mixed and pressed into the joint by hand.
- The surface is finished to suit the stone or brick.
Before we arrive
- Clear the area around the work
- Tell us about any previous sealing or DIY attempts
- Tell us about any water getting in
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 work begins.
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Signs you need sand mastic in Holwellbury
Paint, silicone or cement used over old mastic causes problems. They do not suit the joint and we normally remove them.
Any of these means the joints need attention:
- A silicone bead on a sash window that spoils the look
- Gaps between timber frames and stone or brick
- Failed mastic on an exposed elevation
- Mastic dropping out of the joint
For site and facilities teams at buildings such as Derwent Lower School, larger buildings have plenty of frames, and the mastic around each one ages.
What your quote should include
- How much experience the applicator has
- Which colour the sealant will be
- Whether they seal over old material or remove it
- The length of the guarantee
Can I do it myself?
If you’ve already had a go yourself, that’s fine. We cut it out and start again, so tell us about it when you ask for a quote.
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it does not work out, we can still put it right.
Work for landlords, hotels and businesses
Housing providers, facilities teams and property managers book us too. Several sites can go on one quote.
Failed sealant is one of the commonest items on a check-out report. We can quote for more than one property at once.
Your questions about sand mastic in Holwellbury
I let a flat near Arlesey station. Can you help?
Yes, we work for landlords and agents. You can call 0345 464 0079 or send us an email with the address and a few details, and we’ll give you a fixed price before we start.
Is Holwellbury within the area you cover?
Yes. Holwellbury 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.
Where are you based?
We work from Crawley. Our applicators cover Holwellbury.
What’s sand mastic made of?
It’s sand mixed with a linseed-oil-based binder, used between timber frames and stone or brick.
How long does sand mastic take?
Most jobs take anything from a few hours to a full day, depending on how many windows, including preparation and clearing up. We will confirm how long when we quote.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so the joint is cleaned back first.
Are you an approved applicator?
Yes. We are approved under the ARBOMaster scheme.
Can you do several jobs on one visit?
Yes. Just list everything you need and you’ll get one quote.
How we quote for sand mastic
You will get a clear quote before any work starts. It takes into account:
- Whether the work is at height
- The type of sealant required
- How many areas need sealing
- Any working-time requirements on site
Doing several joints on one visit is usually more efficient than separate visits, so it’s worth mentioning everything you’d like done. You’ll get one clear quote for the whole job.
What we need to know
Photos by email are helpful but not essential. Please mention:
- A few photos by email, if you can
- Whether it’s a home or a business
- What’s wrong with the joints now
- The rough size of the job
It all starts with a short chat. Tell us what’s wrong, where it is and how much there is, and we’ll explain how we’d tackle it. When it suits you, call 0345 464 0079 or email us.
Holwellbury homes and the weather
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.
In the older streets around Church of St Peter (C of E) at Corner with Holwell Road, 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 Arlesey station, any sash windows need sound mastic to keep draughts and rain out.
Holwellbury is about 3 miles north-west of Letchworth, in Hertfordshire. Homes, rented property, offices and hotels in Holwellbury can book us for sand mastic. Every job comes with our one-year guarantee. Across Hertfordshire, we cover 381 places, Holwellbury among them. You can also see our page for London, about 35 miles away.
Here we cover the SG5 postcode area for sand mastic. Other places close to Holwellbury include Ickleford (2 miles south), Westmill (3 miles south), Bearton (3 miles south), Letchworth Garden City (3 miles south-east) and Walsworth (3 miles south-east). Within a short drive, we also cover Stevenage (8 miles south-east), Welwyn Garden City (14 miles south), Harpenden (13 miles south), Hitchin (3 miles south), Stotfold (3 miles north-east) and Baldock (5 miles east).
Landmarks near Holwellbury
In Holwellbury, that means homes and buildings near The Priory School and the streets around them. Holwellbury’s nearest station is Arlesey station, about 2.4 miles north-east of the centre. Well-known places in the area include Fairfield Hospital (2.1 miles east) and Wymondley Castle (4.6 miles south-east). Not far away are Arlesey Old Moat and Glebe Meadows and Markham's Hill.
What the job involves on each surface
Timber door frames
Period doors in stone or brick openings are often pointed with sand mastic. The method is the same as for windows.
Tenement and terrace windows
Tenements and terraces often have many sash windows with ageing mastic. We work on single windows or whole elevations.
Leave it or put it right?
Draughts round a sash window are not always the sashes. Gaps between the frame and the wall can be just as bad and new mastic seals them. Around Holwellbury, older homes often have timber in their floors and frames, and water through a failed joint can rot timber if it’s left.
A few things move the cost up or down: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
Why Holwellbury customers choose us
- We never seal over old sealant
- Homes, businesses and hotels
- Every job guaranteed for a year
- Anti-fungal silicone where joints get wet
See what affects the cost and customer reviews.