Hertfordshire · England
Sand mastic for sash & case windows in Bedwell, Hertfordshire
Traditional burnt sand mastic around sash and case windows and doors in stone and brick in Bedwell, with a 12-month guarantee on every job. Call for a quick quote.
- Tired mastic found when preparing windows for paint
- Wind and rain getting in round a sash window
- Silicone on a period window that looks wrong
Should I try it myself first?
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and does not move well, and getting the depth right matters as much as the look.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. Where it goes wrong is sealing over the old bead, working on a wet joint or overloading the gap.
About our sand mastic in Bedwell
Sand mastic has long been used to fill the joint between timber frames and masonry. It’s made from sand and a linseed-oil-based binder, applied by hand. On older homes, it suits the building far better than silicone. We work on period & listed homes, tenement windows and sash and case windows, and people most often call us about gaps round a timber door in stone or brick and modern sealant on a period surround.
Homes around Bedwell 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.
Our work is backed for twelve months.
- Where
- Bedwell (SG1, SG2)
- Wider area
- Hertfordshire
- Guarantee
- One year on every job
- Quote
- Quoted before any work starts
- Call
- 0345 464 0079
- Last updated
- 26 October 2026
Different surfaces, different methods
Sash and case windows
The box of a sash and case window sits in the stone or brick opening. The gap round it is pointed with sand mastic.
Timber door frames
Door frames get knocked and soaked, so their mastic can fail sooner. We rake it out and renew it.
Signs you need sand mastic in Bedwell
Water gets into small cracks in the mastic and loosens it further. Exposed elevations normally fail first.
The problems people generally mention when they call are:
- Old cement repairs round a window that have failed
- Gaps between timber frames and stone or brick
- Gaps round a timber door in stone or brick
- Weathered mastic on the most exposed windows
If you look after a building such as Broom Barns Primary School, larger buildings have plenty of frames, and the mastic around each one ages.
Before booking anyone
- How much experience the applicator has
- What product goes in the joint
- How the colour is chosen
- Whether they’re fully insured
Also near Bedwell
Also in Bedwell
Landlord and commercial work in Bedwell
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Keeping joints in good order is simple maintenance that we can handle for you.
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we will quote.
Bedwell 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. Historic houses like Knebworth House (about 2.4 miles south-west) are a reminder that the area around Bedwell has older buildings as well as new. In older buildings, older frames set in brick or stone need a sealant that suits them, and sometimes that’s traditional sand mastic.
For an older house near a landmark such as Parish Church of St Andrew and St George, 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 Stevenage station, any sash windows need sound mastic to keep draughts and rain out.
Bedwell is about 1 mile south-west of Stevenage, in Hertfordshire. Bedwell gets the same service as everywhere we cover: old sealant removed completely, careful preparation and a one-year guarantee. Our area takes in 381 places across Hertfordshire, large and small. Our London page covers work nearby.
We cover every part of the SG1 and SG2 postcode area for sand mastic. Local streets include Fox Road, Penn Road and Silam Road, all of which we cover. Being close to the A1155, Bedwell is simple for us to get to for sand mastic. If you’re just outside Bedwell, we cover Stevenage (1 mile north-east), Pin Green (1 mile north), Chells (1 mile north-east), Rooks Nest (1 mile north) and St Nicholas (1 mile north-east). Within a short drive, we also cover St Albans (12 miles south-west), Bishop's Stortford (15 miles east), Welwyn Garden City (7 miles south), Harpenden (9 miles south-west), Hitchin (5 miles north-west) and Hoddesdon (13 miles south-east).
What’s near Bedwell
Around Bedwell, our work takes us to homes and buildings near The Heathcote School, Marriotts School and The Standard Bearer pub, among other places. The closest station to Bedwell is Stevenage station, about 0.7 miles west. Well-known places in the area include Wymondley Castle (3.2 miles north-west) and Stevenage Museum (under half a mile south-west). For a walk, there’s Pryor's Wood.
What we do, step by step
When we arrive, we start by going over the job with you, so there are no surprises. We protect the surfaces around the joints before any work begins. Most jobs take a few hours for a single window, longer for several. In a smaller place like Bedwell, 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.
- First we agree which joints need doing.
- Old mastic and any loose material are raked out.
- We pack any deep voids first.
- We apply the mastic by hand and shape it.
- We dress the finish so it sits neatly against the masonry.
Before we arrive
- Keep pets and children clear of the area while we work
- Let us know about earlier repairs to the joints
- For business premises, tell us about site rules or sign-in
Ask for a quote
There’s no standard price list, because every job is different. Instead, we give you a clear price for your job. To arrange one, call 0345 464 0079 or email us.
Related advice
FAQs for Bedwell
Is it worth replacing old sealant in an older home in Bedwell?
Normally, yes, if it’s cracked, shrunk, mouldy or coming away. The key is cutting all the old sealant out, as new sealant will not bond to it.
Can you help a landlord with a rental near Stevenage station?
Yes, landlords and agents are among the people we work for, and several properties can be quoted together. Just phone 0345 464 0079 or send us an email with the address and what needs doing, and we will give you a clear price.
Can new sealant go over the old?
No. We remove every bit of old sealant first, so the new joint bonds to clean surfaces.
What do you put in the joint?
We choose the sealant for the joint, not the other way round. Movement, water and weather all affect the choice, and we’ll explain our choice.
Can old silicone round a sash window be swapped for sand mastic?
Normally, yes. Once the silicone is out and the joint prepared, sand mastic is applied by hand.
Should I use sand mastic or silicone?
Sand mastic usually suits period timber windows best. Modern frames normally suit a flexible sealant.
Will it make a mess?
Very little: the area around the joints is protected first, and we tidy up before we go.
How long does the job take?
Typically it takes a few hours for a single window, longer for several. Bigger jobs take longer, and we will tell you how long to expect.
What affects the quote in Bedwell
The quote reflects the job in front of us. We take into account:
- The old material and how stubborn it is
- Which sealant suits the joint
- The number of rooms or windows
- The number and length of the joints
A few things move the cost up or down: how much old sealant there is and how stubborn it is, any mould to treat, and whether we need extra access for height. Your quote takes all of that into account.
Helping us quote
Before you ask for a quote, have a think about:
- How many joints, rooms or windows are involved
- Access, such as stairs, a lift or height
- Pictures of the joints, sent by email
- Where the property is
Asking for a quote is easy: tell us what needs doing and where, and roughly how big it is. A few pictures by email make the job easier to understand, and we will come back to you with a quote.
Why deal with it now?
Before painting the windows, it pays to renew the mastic. Paint over cracked mastic will not stop the gaps, and the new mastic is traditionally left unpainted. Homes in smaller places like Bedwell can face more weather, and failed outside joints let damp into walls. Inside, a split seal lets water into floors and panels just as it would anywhere.
Every job is a little different, so each one gets its own quote. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Why choose Mr Mastic in Bedwell
- We leave the area clean and tidy
- Homes, businesses and hotels
- 180+ five-star Google reviews
- Any old sealant cut out fully, not covered over
Read what affects the cost or what customers say.