Hertfordshire · England
Elstree Sand Mastic
Problem with your window and door surrounds in Elstree? We remove the old material, prepare the joints and seal them properly.
- Modern sealant on a period surround
- Mastic dropping out of the joint
- Cracked mastic round a front door frame
How we handle sand mastic in Elstree
For a listed home or one in a conservation area, ask your local planning authority if consent is needed before window work. Sand mastic is often favoured as a like-for-like material. Typical jobs include mastic that needs renewing before redecorating and cement or filler used on old window joints that has cracked, across sash and case windows, stone surrounds and brick reveals.
In a village or hamlet like Elstree, older cottages and farmhouses often have timber windows set in stone or brick. Older buildings like these don’t always suit modern silicone, so the sealant has to be chosen to suit the building.
We stand behind the work with a 12-month guarantee, so you are covered after we have gone.
- Location
- Elstree (WD6)
- Region
- Hertfordshire
- Guarantee
- A year, on every job
- Quotes
- A clear price before any work starts
- Phone
- 0345 464 0079
- Last updated
- 26 October 2026
Elstree homes and the weather
With historic houses such as Headstone Manor (about 4.1 miles south-west) nearby, there’s older building stock in the area around Elstree as well as newer homes. 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. The South East is one of the drier parts of the UK, though outdoor sealant still has to go onto a dry joint, so the forecast decides the day.
Homes close to Church of St Nicholas include some older properties, and frames set in older brick or stone need a sealant that suits the wall as well as the frame. Schools such as St Nicholas Elstree Church of England VA Primary School are buildings too, and its window and door frames need their mastic kept sound, just like a home’s.
Elstree is about 2 miles south-west of Borehamwood, in Hertfordshire. Anywhere in WD6, we cover sand mastic for homes and businesses. Our Hertfordshire coverage runs to 381 places, and Elstree is one of them. For nearby work, see our London page (13 miles or so).
All of WD6 is within our area for sand mastic. You will find streets such as High Street, West View Gardens and Summer Grove. Nearby, we also carry out sand mastic in Deacon's Hill (1 mile east), Edgware Bury (1 mile south-east), Broadfields Estate (2 miles south-east), Borehamwood (2 miles north-east) and Edgware (2 miles south-east). Larger places within reach include Watford (5 miles west), Hemel Hempstead (10 miles north-west), St Albans (8 miles north), Welwyn Garden City (12 miles north-east), Harpenden (12 miles north) and Hoddesdon (14 miles north-east).
Near you in Elstree
In Elstree, that means homes and buildings near The Holly Bush pub, London Academy and Aldenham Country Park, among other places. The nearest railway station is Elstree & Borehamwood station, about 1.1 miles north-east of the centre. Well-known places in the area include Elstree and Borehamwood Museum (1.4 miles north-east) and Royal National Orthopaedic Hospital (0.8 miles south). The countryside around Elstree includes Darland's Lake and Edgware Way Grassland.
Towns and villages near Elstree
Also in Elstree
What happens on the day
All our tools and materials come with us in the van, so you do not need to buy or prepare anything. Once we have agreed what’s being done, the area is protected and the work begins. It normally takes anything from a few hours to a full day, depending on how many windows. Somewhere like Elstree needs a little journey planning: tell us about narrow lanes, gates, long drives and where we can park. Everything for the job comes with us, so a second trip is avoided where possible.
- 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.
- The mastic is mixed, pressed into the joint by hand and shaped.
- The finish is dressed so it sits neatly against the stone or brick.
How to prepare
- Clear items away from the joints we are working on
- Keep pets and children clear of the area while we work
- Mention any leaks or damp you’ve noticed
Ask for a quote
Quotes start with a quick conversation. Describe the problem, the location and the size of the job, and we’ll talk you through what we’d do. When it suits you, call 0345 464 0079 or email us.
Related advice
What the job involves on each surface
Stone surrounds
Old stone surrounds are often uneven, so the joint varies in width. We shape it by hand to follow the stone.
Tenement and terrace windows
Upper-floor windows need access planning. Let us know the floor and we’ll confirm access.
Common problems we fix in Elstree
Rain on the window surround works into any crack and pushes it out. Windows facing the weather tend to go first.
If you can see any of these, it’s time to have the joints looked at:
- Mastic dropping out of the joint
- Modern sealant on a period surround
- Mastic worn away on windows facing the weather
- Gaps between timber frames and stone or brick
Rented homes near Elstree & Borehamwood station change hands often, and any sash windows need sound mastic to keep draughts and rain out.
What to look for in a quote
- Is the old sealant removed completely?
- What preparation is included
- What happens if they find a problem under the old sealant
- Are they insured?
What affects the cost of sand mastic
You’ll get a clear quote before any work starts. It takes into account:
- The product the joint needs
- Whether there’s mould to deal with
- The amount of work
- Whether old sealant or filler has to be cut out
Doing several joints on one visit normally makes better use of the time than several visits, so tell us about everything that needs sealing. You will get one clear quote for the whole job.
What to tell us for a quote
To make quoting easier, please include:
- Photos by email, if that is easy
- What’s wrong with the joints now
- Access, such as stairs, a lift or height
- Whether it’s a home or a business
For a quote, call 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. You will have a clear quote before we start.
Work for landlords, hotels and businesses
A neglected joint can let water reach the structure, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
Letting agents and landlords in Elstree can book us as well as householders. Sealant work between tenants is a simple way to keep a property in good order before the next move-in.
Your questions about sand mastic in Elstree
Can you do sand mastic in Elstree?
Yes, Elstree is within the area we cover. We work across London and the South East. Just ring 0345 464 0079 or drop us an email with a few details of the job, and we’ll send you a clear quote.
Is Elstree within the area you cover?
Yes, we do. Our work covers London and the South East, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Which products do you use?
Products from Arbo and Everbuild, among others, chosen to suit the joint. We’ll tell you what we’re using and why.
Which is right for my windows, sand mastic or modern sealant?
We will talk it through with you. Sand mastic suits many period homes, and modern sealants suit newer frames.
Is it possible to take out silicone and use sand mastic instead?
Normally, yes. With the silicone removed and the joint cleaned we point it with sand mastic.
Can you match the sealant colour?
We help you choose a colour that suits. The choice depends on the product the joint needs.
Are you an approved applicator?
Yes. Mr Mastic is an ARBOMaster approved applicator.
What does sand mastic cost?
Size, access and the old material all affect the cost. Ask us for a quote.
How to look after the new joints
Good habits help new joints last longer. Our tips:
- Leave the new mastic unpainted
- Avoid patching sand mastic with silicone
- Check with your local planning authority if your home is listed
- Ask a joiner to look at soft timber first
Leave the new mastic alone while it firms up. It skins over quickly, but takes longer to harden fully.
Small cracks are a sign the mastic is ageing. It’s easier to renew it before it drops out.
Should I try it myself first?
What a professional job adds is preparation and the right product. Joints are cleaned back to sound surfaces and dried, and the sealant is matched to the joint and its conditions.
Overfilling a joint is a classic DIY mistake. A heavy bead looks messy and copes badly with movement, and getting the depth right matters as much as the look.