Hertfordshire · England
Sand mastic for sash & case windows in Broad Colney, Hertfordshire
Our applicators work in Broad Colney on traditional burnt sand mastic around sash and case windows and doors in stone and brick. Old sealant removed completely, joints prepared properly.
- Open joints round the window box
- Wind and rain getting in round a sash window
- A silicone bead on a sash window that spoils the look
Your questions about sand mastic in Broad Colney
Can you help a landlord with a rental near Park Street station?
Yes, landlords and agents are among the people we work for. Just phone 0345 464 0079 or drop us an email with the address and what needs doing, and we will send you a clear quote.
Is Broad Colney in your area for sand mastic?
Yes, Broad Colney is within the area we cover. We work across London and the South East. Just call 0345 464 0079 or drop us an email with a few details of the job, and we will send you a clear quote.
Is it OK to seal over old sealant?
No. We remove every bit of old sealant first.
Is the work guaranteed?
Our 12-month guarantee applies on every job.
Can you match the sealant colour?
We’ll suggest a colour to suit the surroundings. The choice depends on the product the joint needs.
Will the old sealant be removed?
Always. Sealing over the old bead is the commonest cause of early failure, so we never do it.
Where do you work from?
Our base is in Crawley, and we cover South East England, London and all of Scotland.
Will there be a smell?
There can be a smell while the sealant cures, which fades as it sets. Ventilation helps.
About our sand mastic in Broad Colney
Sand mastic doesn’t last for ever, leaving gaps round the window. We rake it out and renew it so the surround looks right again. We work on stone surrounds, brick reveals and sash and case windows, and common reasons people get in touch are weathered mastic on the most exposed windows and mastic dropping out of the joint.
Outdoor sealant needs dry, clean surfaces, so work on frames around Broad Colney is planned for dry weather. Tell us about access to every side of the house, including upper-floor windows.
There’s a 12-month guarantee on every job, whatever its size.
- Where
- Broad Colney (AL2)
- Wider area
- Hertfordshire
- Guarantee
- One year on every job
- Price
- Quoted before any work starts
- Telephone
- 0345 464 0079
- Last updated
- 26 October 2026
Why act early in Broad Colney
Not every filler suits an old window surround. Sand mastic matches what was there, which can matter on listed and conservation-area homes. Around Broad Colney, older homes often have timber in their floors and frames, where water from a failed joint can cause rot if it’s left.
Every job is a little different, so we quote each one individually. Size, access and the product the joint needs all play a part, and we will explain the quote if you ask.
Why us?
- Old sealant always removed completely
- Full insurance on every job
- Domestic, commercial and hotel work
- Approved under the ARBOMaster scheme
Take a look at our cost guide and what customers say.
Places near Broad Colney
Other services in Broad Colney
When to call us in Broad Colney
Scraping and sanding before painting can loosen old mastic. It’s often found when windows are being prepared for paint, which is a good time to renew it.
Common reasons people contact us are:
- Open joints round the window box
- Mastic worn away on windows facing the weather
- Gaps round a timber door in stone or brick
- Draughty sash windows at the surround
Letting a property close to Park Street station? Then older sash windows in a rental need their mastic kept sound to keep the weather out.
Questions to ask before booking
- How the joint is cleaned and prepared
- How the colour is chosen
- How hidden problems are handled
- What the cure time is
The process
Our applicators work methodically: protection first, then preparation, sealing and a tidy-up. For most jobs that takes a few hours for a single window, longer for several, and the area is left clean. In a small place like Broad Colney, access is generally the main thing to plan. If the job is outside, mention outbuildings, exposed walls and how to reach them.
- We check the window surrounds and agree which joints need renewing.
- Old, loose mastic is raked out and the joint cleaned.
- We pack any deep gaps so the mastic sits at the right depth.
- The mastic is mixed, pressed into the joint by hand and shaped.
- We dress the surface so it sits neatly against the masonry.
How to prepare
- Mention any tricky access
- Keep children and pets away from the work area
- For indoor joints, keep the area dry beforehand if you can
Get a quote
Quotes start with a quick conversation. Tell us what’s wrong, where it is and how much there is, and we will explain how we’d tackle it. Whenever you are ready, call 0345 464 0079 or drop us an email.
Related advice
Aftercare tips
Aftercare is simple:
- Keep modern sealant off the mastic
- Ask a joiner to look at soft timber first
- Make sure water runs off the sill
- Check the mastic when you check the paintwork
Avoid painting over the new mastic, which is the traditional advice. Ask us before any decorating around it.
Renewing mastic before redecorating saves doing it twice. Painting over failed mastic hides the problem for a while.
What affects the quote in Broad Colney
We don’t publish a price list, because no two jobs are the same. What we look at:
- How much old sealant there is and how hard it is to remove
- The number and length of the joints
- Any mould that needs treating
- How many areas need sealing
There are no prices on our website, because the cost depends so much on the job itself. For a quick quote, please phone 0345 464 0079 or send us an email and we will talk you through it.
What to tell us for a quote
Photos help, but a description is a good start. Try to tell us:
- The address or postcode of the job
- The problem you’ve noticed
- Pictures of the joints, sent by email
- If it’s domestic, commercial or a hotel
To get a quote, ring 0345 464 0079 or send us an email and tell us where the job is and what the problem looks like. We’ll send you a clear quote before any work starts.
Sand mastic in Broad Colney: local notes
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. Historic houses like High Elms Manor (about 4.1 miles west) are a reminder that the area around Broad Colney 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 is traditional sand mastic.
Homes close to Church of St Peter include some older properties, and the windows may be timber, sash or later replacements, and each needs the right sealant against the wall. For site and facilities teams at buildings such as Saint Bernadette Catholic Primary School, the mastic around its windows and doors needs looking after like any other building’s.
Broad Colney is about 3 miles south-east of St Albans, in Hertfordshire. We provide sand mastic to householders, landlords and businesses in Broad Colney, as part of our work across Hertfordshire. We cover 381 towns and villages across Hertfordshire, large and small. Our London page covers work nearby, about 17 miles away.
Our applicators cover all of AL2 for sand mastic. Close by, we work in London Colney (1 mile north), Shenleybury (1 mile south-east), Tyttenhanger (2 miles north), Sleapshyde (3 miles north-east) and Colney Heath (3 miles north-east). Within a short drive, we also cover Watford (6 miles south-west), Hemel Hempstead (7 miles west), Stevenage (14 miles north), St Albans (3 miles north-west), Welwyn Garden City (7 miles north-east) and Harpenden (7 miles north).
Landmarks near Broad Colney
We work in homes and buildings around The White Lion pub and Samuel Ryder Academy. For rail, the closest station is Park Street station, about 1.9 miles north-west. Nearby you’ll also find Hilfield Castle (4.5 miles south) and Radlett and District Museum (2.5 miles south). The countryside around Broad Colney includes Verulamium Lake and Broad Colney Lakes.
Landlord and commercial work in Broad Colney
Water getting past a failed joint can damage the building, which matters even more when someone else lives there. Resealing at the right time is simple maintenance.
We regularly work with letting and managing agents. Send the address, what’s needed and the access arrangements and we will quote.
When it is not the sealant
It helps to know what we cannot do too:
- Timber that has rotted
- Damaged stone surrounds
- Sashes that need overhauling
Not sure which it is? You can ring 0345 464 0079 or email us and we will tell you honestly before you book.
Where we work in Broad Colney
- Brick reveals
- Period & listed homes
- Timber door frames
- Tenement windows
- Stone surrounds
- Sash and case windows