Hertfordshire · England
Baldock Sand Mastic
Traditional burnt sand mastic around sash and case windows and doors in stone and brick for Baldock, backed by a 12-month guarantee. Call for a quick quote.
- Draughty sash windows at the surround
- Mastic dropping out of the joint
- Weathered mastic on the most exposed windows
About our sand mastic in Baldock
If your home is listed or in a conservation area, check with your local planning authority whether consent is needed for work to windows. Sand mastic is often favoured as a like-for-like material. If you have mastic dropping out of the joint and old cement repairs round a window that have failed, we can put it right.
Homes around Baldock range from older properties to newer houses, and their windows range just as widely. Each frame material needs the right sealant against the right wall.
Whatever the size of the job, it’s backed by our 12-month guarantee in Baldock and across Hertfordshire.
- Location
- Baldock (SG7, SG6)
- Wider area
- Hertfordshire
- Cover
- One year on every job
- Quote
- A clear price before we start
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Can I do it myself?
Sealing over old silicone is the commonest DIY error. New silicone won’t bond to old, so it lifts and traps water and mould underneath. Everything old must be removed first.
If you are set on DIY, put the effort into preparation: remove every trace of old sealant, clean and dry the joint, and follow the product’s cure time. If it does not work out, we can still put it right.
Honest limits
Sealant isn’t the answer to every problem, and we’d rather say so up front. It won’t solve:
- Whether work needs listed building consent
- Broken panes
- Rotten sashes, sills or window boxes (a joiner’s job)
Not sure which it is? You can call 0345 464 0079 or email us and we’ll tell you honestly.
What we seal
- Sash and case windows
- Period & listed homes
- Stone surrounds
- Timber door frames
- Tenement windows
- Brick reveals
What the job involves on each surface
Stone surrounds
Sand mastic sits naturally against stone. The finish blends with the masonry.
Sash and case windows
The mastic round a sash window is on show so we finish it carefully.
How the visit works
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. Typically it takes anything from a few hours to a full day, depending on how many windows. A visit to Baldock 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 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
- Mention any sign-in or site rules at work premises
- Let us know if you’ve seen damp or leaks
- Clear items away from the joints we’re working on
How to get a quote
It all starts with a short chat. Describe the problem, the location and the size of the job. When it suits you, ring 0345 464 0079 or drop us an email.
Read more
Questions from Baldock
Is Baldock in your area for sand mastic?
Yes. Our work covers London and the South East, and Baldock is part of that. Just phone 0345 464 0079 or email us with a few details of the job, and we’ll give you a clear price.
Is Baldock within the area you cover?
Yes, smaller places are covered as well as towns. We work across London and the South East. Just mention lanes, gates or anything else about the route when you book.
Is it messy?
Very little: the area around the joints is protected first, and we tidy up before we go.
I rent my home. Can I book you?
We can work for tenants, landlords or agents. Get your landlord’s agreement first.
Can I choose the sealant colour?
We help you choose a colour that suits, from white and clear to greys and other shades. The product needed can limit the range.
What exactly is sand mastic?
It’s the traditional filler for the joint round timber windows and doors. It’s made with sand and a linseed-oil-based binder.
What sealant do you use?
Quality sealants from brands including Arbo and Everbuild, chosen to suit the joint. We will tell you what we’re using and why.
Does someone need to be in?
Access is agreed with you when the job is booked. Indoors, that normally means someone at home.
Common problems we fix in Baldock
Timber swells and shrinks with the weather. That movement opens up the mastic joint little by little.
People usually contact us when they notice something like this:
- Tired mastic found when preparing windows for paint
- Gaps round a timber door in stone or brick
- Wind and rain getting in round a sash window
- Mastic dropping out of the joint
Managing a site like Hartsfield Junior Mixed and Infant School? Then larger buildings have plenty of frames, and the mastic around each one ages.
What your quote should include
- How the colour is chosen
- Is the old sealant removed completely?
- How long to leave it before use
- What happens if the job turns out different
Why it’s worth doing now in Baldock
Silicone might seem the quicker option, but on period stone or brick it often looks out of place. Sand mastic is the traditional material and blends with the stone or brick. Around Baldock, water from a failed joint in an older home can soak into timber and plaster, which is far harder to put right than the sealant itself.
What you pay reflects the work, not guesswork. That’s why we ask about the job first.
Why book with us
- 180+ five-star Google reviews
- 20+ years of sealant experience
- Quality sealants from Arbo and Everbuild
- Tidy, careful work
Take a look at how sealant jobs are priced and our reviews.
Sand mastic in Baldock: local notes
Historic houses like Hinxworth Place (about 3.6 miles north) are a reminder that the area around Baldock 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’s 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.
Homes close to Church of St. Mary the Virgin include some older properties, and the joint between an old wall and a newer frame is normally the first place rain gets in. If you let a flat or house near Baldock station, any sash windows need sound mastic to keep draughts and rain out.
Baldock is about 2 miles north-east of Letchworth, in Hertfordshire. If you need sand mastic in Baldock, it’s easy to get a quote: please ring 0345 464 0079 or drop us an email. We cover Hertfordshire from our Crawley base. Our Hertfordshire coverage runs to 381 places, Baldock among them. Our London page covers work nearby.
Postcode districts we cover here for sand mastic: SG7 and SG6. We cover properties on High Street, Station Road and London Road and the roads around them. Baldock sits on or near the A507 and B197. Close by, we work in Clothall (2 miles south-east), Weston (2 miles south), Wallington (3 miles east), Rooks Nest (4 miles south) and St Nicholas (5 miles south). Within a short drive, we also cover Stevenage (6 miles south), Welwyn Garden City (13 miles south), Harpenden (14 miles south-west), Hitchin (5 miles south-west), Hertford (14 miles south) and Ware (14 miles south-east).
Near you in Baldock
Around Baldock, our work takes us to homes and buildings near Norton School, The Knights Templar School and The White Lion Public House. Baldock has its own railway station: Baldock station. Nearby you’ll also find Fairfield Hospital (2.8 miles west) and First Garden City Heritage Museum (1.8 miles south-west). Not far away are Purwell Ninesprings.
Work for landlords, hotels and businesses
Businesses can book us for washrooms, kitchens, offices and more. On commercial sites, working times can be discussed when we quote.
We work for landlords and letting agents as well as homeowners. Resealing between tenancies keeps a property looking cared for before the next move-in.