Scottish Borders · Scotland
Sand Mastic in Duns
Window and door surrounds in Duns need attention? We remove the old material, prepare the joints and seal them properly, with a one-year guarantee.
- Draughts and rain around sash boxes
- Tired mastic found when preparing windows for paint
- Mastic round period door frames that has failed
DIY versus a professional finish
Too much sealant is as bad as too little. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Not every job suits DIY: high-level joints, fire-rated gaps, external movement joints and big jobs need the right product, the right access and the right method.
Sand mastic in Duns, done properly
Old sand mastic cracks, crumbles and falls out over time, leaving gaps round the window. Renewing it closes the gap so the surround looks right again. If you have draughts and rain around sash boxes and old cement repairs round a window that have failed, we can help, whatever the surface.
Many older Scottish homes still have timber windows set into stone walls. Those suit a traditional sand mastic or a neutral-cure sealant, not an acetoxy silicone that can attack some stone.
Whatever the size of the job, you get the same one-year guarantee.
- Where
- Duns (TD11)
- Region
- Scottish Borders
- Cover
- A year, on every job
- Quote
- A clear quote up front
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
What else we do in Duns
What sand mastic looks like in Duns
Many older homes in Scotland have sash and case windows, often pointed into the wall with traditional sand mastic. Under the Repairing Standard, private landlords in Scotland have to keep homes wind and watertight, and failed outside joints work against that.
In the older streets around Old Parish Church, the windows may be timber, sash or later replacements, and each needs the right sealant against the wall.
Duns is in the Scottish Borders. Every kind of property in Duns is covered for sand mastic. The work is guaranteed for a year. 89 places in the Scottish Borders are on our list, large and small. For nearby work, see our Edinburgh page.
Every address in TD11 is within our area for sand mastic, from the main roads to the quietest streets. Sand mastic is available to properties on Market Square, Station Road and Murray Crescent. Duns is on the A6105 and A6112, which makes it straightforward to reach with everything needed for sand mastic. We also cover the places around Duns: Clockmill (1 mile west), Gavinton (1 mile south-west), Preston (2 miles north), Swinton (5 miles south-east) and Chirnside (5 miles east). As one of the bigger places in the Scottish Borders, Duns has homes, rented property and businesses of every kind.
What’s near Duns
In Duns, that means homes and buildings near The Royal Bar, among other places. Other landmarks nearby include Knoll Hospital (less than half a mile south) and Jim Clark Motorsport Museum (under half a mile west). For a walk, there’s Duns Law and Duns Castle nature reserve.
Duns: your questions answered
Is sand mastic in Duns guaranteed?
All our work, in Duns and everywhere else, comes with a 12-month guarantee. We’re also fully insured and ARBOMaster approved.
Is Duns in your area for sand mastic?
Yes. We work across all of Scotland, and Duns is part of that. Just send an email to info@mrmastic.co.uk with a few details of the job.
Are you an approved applicator?
Yes. We’re ARBOMaster approved, the scheme for applicators of Arbo sealants.
What does sand mastic cost?
We do not publish prices, because the cost depends on the job: its size, the old material, access and the product needed. You’ll get a clear quote before work begins.
Do you remove the old sealant?
Always. Sealing over old sealant is the main reason resealing fails early, and it’s something we never do.
What’s sand mastic made of?
Sand plus a binder based on linseed oil. It’s built up in the joint by hand and finished to sit neatly against the masonry.
Should I check with the council before work on a listed or conservation-area home?
Speak to your local planning authority before work starts. Sand mastic is often favoured as like for like, but they decide.
I rent my home. Can I book you?
Yes. Ask your landlord first, and we can send them the quote if that helps.
Why act early in Duns
Before painting the windows, it pays to renew the mastic. Paint over cracked mastic won’t stop the gaps, and the new mastic is traditionally left unpainted. Exposed walls in smaller Scottish places take a lot of wind and rain, and once water gets behind a failed joint, damp in stone or harled walls is slow to dry out.
Rather than a set price list, we price the job in front of us: how many joints, what’s in them now and how we reach them. You’ll know the price before we begin.
Why Duns customers choose us
- A 12-month guarantee on all work
- Rated 4.9 stars on Google
- Quality sealants from Arbo and Everbuild
- Experience in homes, commercial sites and hotels
Take a look at how sealant jobs are priced or customer reviews.
Aftercare tips
To keep the joints looking good and working properly:
- Sort the mastic before the decorators arrive
- Avoid heavy scraping on the mastic joint
- Don’t run silicone over sand mastic
- Keep sills and gutters clear so water drains away
Check the mastic when you check the paintwork. Catching cracks early keeps repairs small.
An open joint round the box lets weather through. Left, the gap tends to get bigger as more mastic falls out.
Signs you need sand mastic in Duns
Rain on the window surround works into any crack and loosens it further. Windows facing the weather tend to go first.
These are the problems we’re asked about most:
- Open joints round the window box
- Modern sealant on a period surround
- Window mastic to renew ahead of painting
- Failed mastic on an exposed elevation
Schools such as Berwickshire High School are buildings too, and the mastic around its windows and doors needs looking after like any other building’s.
Before booking anyone
- Which colour the sealant will be
- How much experience the applicator has
- How the surfaces are prepared before sealing
- How hidden problems are handled
Surface by surface
Tenement and terrace windows
In shared buildings, the windows may be part of a wider repair so it’s worth checking responsibilities.
Timber door frames
Round a period front door, sand mastic gives the right look.
What affects the quote in Duns
The quote reflects the job in front of us. We look at:
- Mould in or behind the old joints
- The amount of work
- How easy the joints are to reach
- The number of rooms or windows
What you pay reflects the work, not guesswork. That’s why we ask about the job first and give you a clear quote before we start.
What to tell us for a quote
You don’t need to know the technical terms. It helps if you can tell us:
- The type of property
- The rough size of the job
- Where the job is, and your postcode
- What’s wrong with the joints now
Asking for a quote is easy: let us know the job and the location, and roughly how big it is. Photos by email help us understand the job, and we’ll come back to you with a quote.
The process
All our tools and materials come with us in the van, so you don’t need to buy or prepare anything. Once we have agreed what’s being done, the area is protected and the work begins. Most jobs take a few hours for a single window, longer for several. In smaller Scottish places, parking is generally less of an issue than access and distance. Tell us how to find the property and how to reach the work.
- We start by checking each surround and agreeing the joints to renew.
- The loose and crumbling mastic is raked out and the joint cleaned.
- Deep voids are packed so the mastic is the right thickness.
- Sand mastic is mixed and applied by hand, then shaped to the joint.
- We dress the surface so it sits neatly against the masonry.
Before we arrive
- Keep pets and children clear of the area while we work
- Mention any leaks or damp you’ve noticed
- Tell us about any previous sealing or DIY attempts
Ask for a quote
A good description makes for an accurate quote. Let us know the location, the problem and roughly how many joints, and add pictures by email if you can.