Argyll and Bute · Scotland
Achnacroish External Mastic
Movement joints in Achnacroish need attention? We cut out the old, prepare the joints and apply the right sealant, and the work is guaranteed for a year.
- Plants rooting in failed movement joints
- Hard, crazed mastic that has stopped moving
- Joints with sealant missing in places
For landlords and businesses
We also work for businesses, from offices to washrooms and kitchens. For commercial premises, we can talk through working times when we quote.
In hotels, rooms out of use cost money, so we plan the work room by room around your bookings where we can. We have worked in hotels as well as homes and businesses.
External mastic in Achnacroish, done properly
Short cuts in external joints show up within a season or two. Overfilled joints, missing backing rod and sealant laid over old sealant rarely last long. We strip the joint back and start again. Common call-outs are for weathered mastic that no longer stretches and movement joints with cracked, split or missing sealant, on brickwork movement joints, render & cladding joints and joints between brick and frames.
Older stone buildings need a sealant that suits the stone, not an acetoxy product that can mark or attack it. Newer houses need their movement joints and roofline trims kept sound.
Your job is guaranteed for a year, as with all our work.
- Place
- Achnacroish (PA34)
- Wider area
- Argyll and Bute
- Guarantee
- A year, on every job
- Quote
- A clear price before we start
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Achnacroish: your questions answered
Do you cover smaller places like Achnacroish?
Yes, Achnacroish is covered. We work across all of Scotland, from towns to the smallest places. The journey is planned ahead, so it helps to know about access.
Is external mastic in a coastal place like Achnacroish any different?
Near the coast, wind-driven rain and, nearer the shore, salt air make outside sealant work harder. Choosing the right sealant for the frame and wall, laid at the right depth, helps it last.
Can tenants book the work?
Of course. Check with your landlord; we can send the quote to them too.
When is the sealant fully cured?
Cure times vary by product and the conditions. We tell you how long to leave it before we go.
Will the old sealant be removed?
Yes, every time. New sealant will not bond properly to old, so any old material comes out before anything new goes in.
What is backing rod for?
Backing rod goes into deeper joints as a matter of course. It sets the sealant depth and prevents three-sided bonding.
Can I do it myself?
You can, for simple jobs. Preparation is everything: all the old sealant out, and a clean, dry joint. We can always put it right if it fails.
Why is there a gap in my brick wall?
Brickwork, render and cladding all move a little, so long walls have planned gaps to take that movement. It’s closed with backing rod and a flexible sealant.
How the job changes by surface
Render joints
The face of render can be soft, so a sealant that stretches easily protects the edges. We prime where the product needs it.
Cladding and façade panels
Metal and composite panels move a lot with temperature, so the joints work hard every day. The sealant is chosen with that in mind.
Signs you need external mastic in Achnacroish
Sometimes a movement joint was filled with mortar or a rigid filler. The joint cannot move, so the wall cracks somewhere else instead.
The most common problems we see are:
- Weathered mastic that no longer stretches
- Cracked joints where brick meets render or frames
- Rain getting behind render or cladding at a joint
- Sealant pulling away from one side of the joint
Whether the job is in Achnacroish itself or nearby, the right material for each joint matters as much as a neat finish.
Questions to ask before you book
- How the colour is chosen
- Whether all the old sealant comes out first
- What the cure time is
- Whether they’re fully insured
DIY versus a professional finish
Not every job suits DIY: work at height, external movement joints, fire-rated sealant and large areas call for the right materials, safe access and experience.
A careful DIYer can reseal a simple joint, like a short, easy-to-reach joint indoors. The common mistakes are sealing over old sealant, sealing a damp joint and using far too much.
What we do, step by step
The work is kept neat and contained to the area we’re working on, so you can get on with your day. The job generally takes a few hours to a few days, depending on the length of joint and the access. Outdoor work around Achnacroish depends on the weather, as sealant needs a dry surface, so external jobs may need to move if the day turns wet. Indoor work goes ahead whatever the weather.
- First, the joints are inspected and the access agreed.
- We cut out the old mastic and rake out anything in the joint.
- Joint faces are cleaned back and primed if the sealant needs it.
- Backing rod sized to the joint goes in to set the depth.
- The exterior sealant is applied, tooled and checked along its length.
Preparing for the visit
- Tell us if parking is tricky
- Mention any tricky access
- Try not to wet indoor joints just before the visit
Ask for a quote
Call for a quick quote, or email us if that’s easier. Tell us about the joints that need doing and we will explain what’s involved.
Advice
Leave it or put it right?
Pointing a movement joint with mortar might seem a neat fix, but it locks the joint solid. The movement then cracks the brickwork or render nearby. A flexible sealant over backing rod is what the joint needs. When the nearest tradesperson is a drive away, it’s tempting to leave a small leak, but water through a failed joint keeps working away until it’s fixed.
A failed joint rarely gets cheaper to fix by waiting, because water and mould keep working on it. If you’re unsure, send an email to info@mrmastic.co.uk for an honest opinion and a quote.
What you get with us
- Domestic, commercial and hotel work
- We’re fully insured
- An ARBOMaster approved applicator
- Old sealant always removed completely
Read our cost guide or what customers say.
What external mastic looks like in Achnacroish
Achnacroish is within about 2 miles of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. Both are hard on movement joints and outside wall joints, which can dry out and crack sooner where a building faces the weather. Plenty of Scottish homes have harled walls, and joints where harling meets other materials need a sealant that can grip and flex.
Around Achnacroish, as everywhere, external mastic is only as good as the preparation behind it.
Achnacroish is in Argyll and Bute. Jobs in Achnacroish get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Our area takes in 118 places across Argyll and Bute, large and small. Glasgow is on our list too, about 65 miles from Achnacroish.
Work in PA34 works the same way as everywhere else we cover. We also cover the places around Achnacroish: Balliveolan (1 mile north), Benderloch (4 miles east), Port Appin (5 miles north-east), Dunbeg (5 miles south-east) and North Connel (5 miles south-east). Island and remote addresses take a little more planning, so please mention your location when you drop us a line at info@mrmastic.co.uk.
Local landmarks in Achnacroish
Other landmarks nearby include Coeffin (1.8 miles north) and Lismore Gaelic Heritage Centre (1.3 miles north). Green spaces nearby include Loch Fiart and Barr Mòr.
Keeping the joints in good condition
Joint life depends on how it’s used and looked after. We suggest:
- Never let anyone fill a movement joint with mortar
- Wash walls gently around the sealant
- Walk round the building once a year and look at the joints
- Act on the first splits you see
Make sure anyone working on the wall later knows where the movement joints are. They should be kept open and resealed, not filled.
Once a joint can’t move, the wall finds another way, often as cracks near the joint. Catch it early and you reduce the risk.