Scottish Borders · Scotland
Clockmill External Mastic
We cover Clockmill for sealing brickwork movement joints, render, cladding and façade joints. Old material cut out, joints cleaned and sealed neatly.
- Joints pointed up with cement by mistake
- Sealant pulling away from one side of the joint
- Old sealant gone brittle and cracked
When it isn’t the sealant
It helps to know what we can’t do too:
- Failed render or damaged cladding panels
- Rising or penetrating damp from elsewhere in the wall
- Subsidence or other structural problems
Not sure which it is? You can email us at info@mrmastic.co.uk and we will tell you honestly before you book.
What we seal
- Render & cladding joints
- Concrete & block
- Copings & trims
- Façade panels
- Joints between brick and frames
- Brickwork movement joints
How we handle external mastic in Clockmill
Joints in render and cladding are easy to overlook until a damp patch appears. We look over the joints, agree the ones to renew and reseal with a flexible, weatherproof product in a colour to suit. If you are dealing with failed sealant between panels on a façade and cracked joints where brick meets render or frames, we can help, on façade panels, copings & trims and render & cladding joints alike.
Outside joints can only be sealed when they’re dry, so work in Clockmill depends on the weather, and longer journeys are planned in advance. Let us know about access to every wall and roofline.
The work is guaranteed for twelve months. If something is not right with it in that time, tell us and we will put it right.
- Place
- Clockmill (TD11)
- Region
- Scottish Borders
- Cover
- 12 months on all our work
- Quotes
- A clear price before we start
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
DIY versus a professional finish
If you do try it yourself, take your time over the preparation: take out all the old sealant, make sure the joint is clean and dry, and give it the full cure time. If it fails, we can still redo it.
Sealing over old silicone is the commonest DIY error. Silicone does not stick to old silicone, so it lifts and traps water and mould underneath. All the old material has to come out first.
How the job changes by surface
Brickwork movement joints
Clay brickwork grows slightly over its life and moves with the weather. That movement goes into the joint, so the sealant in it must stay soft and stretchy.
Render joints
Rendered walls have joints at beads, openings and changes of material. We reseal them with a flexible exterior sealant that suits the render colour.
Leave it or put it right?
Sealing over the top of old mastic does not hold for long. New sealant does not bond well to old, weathered sealant, so we always take the old sealant out. Out of town in Scotland, exposed walls take a lot of weather, and damp in stone or harled walls takes a long time to dry once water gets behind a joint.
The cost depends on the size of the job, how hard the old material is to remove and how easy the joints are to reach. You’ll have a clear quote before any work starts.
Why book with us
- Neat joints and a tidy finish
- Arbo and Everbuild products
- Homes, businesses and hotels
- Over 20 years’ experience
Take a look at our cost guide and customer reviews.
Common problems we fix in Clockmill
The wrong product in a moving joint is a classic cause. A high-modulus or general-purpose sealant can be too rigid for a busy joint, and it tears off the sides.
Signs it’s time to call us include:
- Weeds or debris growing in open joints
- Panel joints letting water in
- Brick movement joints where the sealant has split
- Gaps where render, brick and frames meet
Homes close to Old Parish Church of St Cuthbert include some older properties, and old and new materials meet at the roofline and walls, which is where sealant earns its keep.
What your quote should include
- Whether they’re fully insured
- Who turns up on the day
- Is VAT in the price?
- What the cure time is
Walls and rooflines in Clockmill
Harled (roughcast) walls are common in Scotland, and joints where harling meets other materials need a sealant that can grip and flex. Private landlords in Scotland must meet the Repairing Standard, which includes keeping a home wind and watertight, and failed outside joints work against that.
Schools such as Berwickshire High School are buildings too, and its movement joints, gutters and trims need looking after like any other building’s.
Clockmill is in the Scottish Borders. Clockmill gets the same service as everywhere we cover: the old material taken out, joints prepared properly and a 12-month guarantee. Clockmill is one of 89 places in the Scottish Borders where we work for external mastic. Edinburgh is on our list too, about 34 miles from Clockmill.
Our applicators cover all of the TD11 postcode area for external mastic and the streets around it. We also cover Gavinton (1 mile south), Duns (1 mile east), Preston (3 miles north-east), Longformacus (5 miles north-west) and Swinton (6 miles south-east). We also work in nearby towns such as Kelso (12 miles south), Eyemouth (13 miles north-east), Earlston (15 miles south-west), Lauder (15 miles west) and Chirnside (6 miles east).
Local landmarks in Clockmill
A little further out are Jim Clark Motorsport Museum (1 mile east) and Langton Castle (0.8 miles west). For a walk, there’s Hule Moss and Duns Castle nature reserve.
Clockmill: your questions answered
Can you do external mastic in Clockmill?
Yes, Clockmill is within the area we cover. We work across all of Scotland. Just send an email to info@mrmastic.co.uk with a few details of the job, and we’ll send you a clear quote.
Will you come out to Clockmill?
Yes, we do. Our work covers the whole of Scotland, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
When is the sealant fully cured?
That depends on the sealant used, so follow the cure time we give you when we finish.
Will the old sealant be removed?
Yes. We cut out all the old sealant and clean the joint before resealing.
What do you need from me for a quote?
A short description and the location. We will ask anything else we need to know.
How long does the job take?
Most jobs take anything from a few hours to several days, depending on the building, including the preparation. We will confirm how long when we quote.
Do you work at height?
Each building is different. Tell us the height, the number of joints and what’s below them, and we’ll confirm what access is needed.
Should I point up the gap in my brickwork?
No, not if it’s a movement joint. Filling it with mortar defeats its purpose and can lead to cracking. We will reseal it with a flexible sealant.
Aftercare tips
Once the sealant has cured, a few habits help it last:
- Look over the joints every year, ideally after winter
- Keep movement joints as flexible joints, not mortar
- Keep high-pressure jets off the joints
- Act on the first splits you see
Keep the joints clear of soil, plants and climbing growth. Damp material against the sealant shortens its life.
Leaks behind façade panels and render often go unseen. By the time there’s a damp patch, the damage can be well established.
What we do, step by step
When we get to you, we check the joints match what you told us. If we find something unexpected, we talk it through with you first. After that, the work takes anything from a few hours to several days, depending on the building. In smaller Scottish places, parking is normally less of an issue than access and distance. Let us know how to find you and how to reach the joints, and the visit is planned around that.
- We start by checking each joint, agreeing the ones to redo and how we’ll reach them.
- We cut out the failed sealant and rake out any dirt or growth.
- The joint faces are cleaned and primed where the sealant needs it.
- Backing rod goes in next, setting the depth and keeping the sealant off the back of the joint.
- The new sealant, chosen to suit the brick or render, is applied and tooled to a neat finish.
Getting ready for the visit
- Clear items away from the joints we’re working on
- Mention any parking rules near the property
- Mention any leaks or damp you’ve noticed
How to get 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. Whenever you are ready, email us at info@mrmastic.co.uk.