Na h-Eileanan Siar · Scotland
External Mastic in Bac
External mastic for Bac and the surrounding area: careful preparation, the right product and tidy work. Ask us for a quick quote.
- Rigid filler in a joint that should flex
- Water getting into walls through failed joints
- Cracked joints where brick meets render or frames
For landlords and businesses
If you manage several properties in or around Bac, several properties can go on one quote. Send us the addresses and the work at each, and photos by email help.
We also work for businesses, from offices to washrooms and kitchens. On commercial sites, working times can be discussed when we quote.
External mastic in Bac
Movement joints let brickwork, render and cladding expand and shrink without cracking. Its sealant has to flex with the building, season after season, so once it splits or hardens, the joint stops working and water gets in. Typical jobs include panel joints letting water in and water getting into walls through failed joints, across render & cladding joints, concrete & block and copings & trims.
External sealant needs dry surfaces, so outdoor work around Bac is planned around the weather, and longer journeys are planned in advance. Let us know about access to every wall and roofline.
A one-year guarantee comes as standard, so you’re covered after we’ve gone.
- Where
- Bac (HS2)
- Region
- Na h-Eileanan Siar
- Guarantee
- 12 months on all our work
- Quotes
- Quoted before any work starts
- info@mrmastic.co.uk
- Last updated
- 26 October 2026
Also in Bac
Why it’s worth doing now in Bac
A low-modulus sealant is chosen because it moves without pulling hard at the edges. That matters on brick, render and concrete, which can be weaker at the face. A stiffer product can damage the joint edge as it fails. Around Bac, water from a failed joint in an older stone home can soak into timber and plaster.
Some things make a job bigger or smaller: the old material and how easily it comes out, whether mould needs treating, and whether we need extra access for height. We take all of that into account in your quote.
Why choose Mr Mastic in Bac
- Tidy, careful work
- Colour picked to suit the job
- ARBOMaster approved applicator
- We agree the colour with you first
Read what affects the cost and what customers say.
Bac questions
Is Bac in your area for external mastic?
Yes. We work across all of Scotland, and Bac is part of that. Just drop us a line at info@mrmastic.co.uk with a few details of the job, and we’ll give you a clear price.
Is external mastic in a coastal place like Bac any different?
Near the sea, outside joints face more wind, rain and salt than they would inland, so the choice of sealant and the preparation matter even more. It’s worth checking the walls that face the sea first.
Are you fully insured?
Yes, we are fully insured for every job we do.
Can I add another job to the visit?
Yes, we can. Several rooms, windows or areas can go on one quote.
What information do you need?
A short description and the location, with photos by email if possible. We’ll ask anything else we need to know.
Can you work on commercial sites?
Yes. We have worked for hotels, offices and other businesses.
How do you reach high-level joints?
It depends on the height and the site. Ground-floor joints are simple; for higher work, tell us about the building and we will confirm what’s needed.
Can a movement joint be filled with mortar?
No. A mortar-filled joint can’t move, so the movement cracks the wall elsewhere. Use a flexible sealant with backing rod.
What affects the cost of external mastic
The quote reflects the job in front of us. We look at:
- Whether old sealant or filler has to be cut out
- Any mould that needs treating
- The type of sealant required
- How easy the joints are to reach
Doing several joints on one visit normally makes better use of the time than several visits. We will give you a clear price for the lot.
What we need to know
Photos help, but a description is a good start. Try to tell us:
- Where the property is
- Whether it’s a home or a business
- What the problem is, such as mould, gaps, leaks or cracking
- If someone has resealed it before
Want a quote for external mastic? Please drop us a line at info@mrmastic.co.uk and tell us about the job. You will know what we plan to do, and what it will cost, before any work begins.
Signs you need external mastic in Bac
Poor preparation causes many early failures: joint faces that were dusty or damp, unprimed where they needed it, or still carrying old sealant. The sealant never bonds properly.
These are the problems we are asked about most:
- Joints with sealant missing in places
- Leaking joints around cladding and façade panels
- Rain getting behind render or cladding at a joint
- Rigid filler in a joint that should flex
Whether the job is in Bac itself or nearby, the right material for each joint matters as much as a neat finish.
What your quote should include
- Whether the sealant suits the joint
- How long the guarantee is
- How the colour is chosen
- What preparation is included
How to look after the new joints
Simple care keeps the joints in good condition. We recommend:
- Point out the joints to other trades
- Check the sealant is paintable before painting near it
- Walk round the building once a year and look at the joints
- Make sure movement joints aren’t pointed over
Don’t let soil, plants or ivy build up against the new joints. Anything that holds water against the joint wears it out sooner.
Gaps, plants or missing sealant in a joint are worth getting looked at. Early work is quicker and leaves a better finish.
The process
Good joint work is mostly preparation, and we do not rush it. Every joint is cleaned and dried before new material goes in. All told, the work takes a few hours for a handful of joints, longer for a whole elevation. In smaller Scottish places, parking is normally less of an issue than access and distance. Tell us how to find the property and how to reach the work, and the visit is planned around that.
- Each joint is checked and the colour of the new sealant agreed.
- We take out the old sealant until the faces are sound.
- Backing rod goes in so the sealant can stretch between the two faces.
- We prime the faces where required.
- We gun in low-modulus sealant and tool it neatly.
Before we arrive
- Tell us about any previous sealing or DIY attempts
- Let us know about parking restrictions
- Mention any tricky access
Ask for a quote
Every job is quoted individually. Just drop us a line at info@mrmastic.co.uk with the details.
Related advice
When it isn’t the sealant
Some problems need a builder, plumber or other trade rather than us:
- Cracked brickwork or render that needs a builder or plasterer
- Damp from another source, such as a leaking gutter or a bridged damp-proof course
- Loose or hollow render, which needs re-rendering
If in doubt, email us at info@mrmastic.co.uk and we will say what we think.
What we seal
- Façade panels
- Render & cladding joints
- Copings & trims
- Concrete & block
- Joints between brick and frames
- Brickwork movement joints
External mastic in Bac: local notes
Bac is within about 1 mile of the coast, and homes near the sea take more wind-driven rain, with salt in the air closer to the shore. That is hard on movement joints and outside wall joints, especially on the side facing the sea. Island weather, with its wind and salt spray, is tough on movement joints and outside wall joints.
Around Bac, as everywhere, external mastic is only as good as the preparation behind it.
Bac is in Na h-Eileanan Siar. Jobs in Bac get the same care as everywhere else we work: the old material taken out, joints prepared properly and a 12-month guarantee. Bac is one of 87 towns and villages in Na h-Eileanan Siar we cover.
Our applicators cover all of the HS2 postcode area for external mastic. Whether your property is on Broadbay View, Rathad na Sgoile and Rathad an T-Seann Sgoil or a nearby road, our applicators can take on the job. Close by, we work in Upper Coll (2 miles south-west), Aird Tong (2 miles south-west), Tong (3 miles south-west), Steinis (4 miles south-west) and Newmarket (4 miles south-west). As one of the bigger places in Na h-Eileanan Siar, Bac has homes, rented property and businesses of every kind. If you’re somewhere remote, the job takes a little more planning, so let us know when you get in touch.
Around Bac
Well-known places in the area include Western Isles Hospital (4.9 miles south-west). For a walk, there’s Loch Langavat.