Mastic Sealing in Knock
Work needed on a mastic joint in Knock? We look at it, seal it with the right product and hand it over with a 12-month guarantee.
- Damaged joints in communal entrances and corridors
- Movement joints with sealant missing
- Water getting in round frames after rain
Mastic sealing across Knock
Send drawings, photos or a joint schedule, or tell us about the site, and we’ll come back with a fixed quote.
Mastic sealing in Knock
Treatment starts with a proper look: which joints have failed, why, and whether sealant is the right answer. Old mastic is removed entirely, the faces prepared, primer used where the maker specifies it and new sealant tooled in and backing rod used wherever a joint is deep. We work on external wall and movement joints, communal entrances and stairwells and balcony and threshold joints, and the failures we are asked to look at most are estate-wide sealant that is simply worn out and draughts at frames across a block. Sealant contractors, mastic applicators, sealant specialists: whatever the job title on the order, the work in Knock is the same: failed joints cut out, faces prepared and the right sealant laid to the right depth.
For buildings around Knock, we group the work to keep travel and visits down. Send addresses and photographs for a quote covering the batch.
Our 12-month guarantee is about workmanship, not wear and tear. How long a sealant joint lasts depends on movement, exposure, cleaning and use, so we’re clear about what is covered before work starts.
- Location
- Knock (HS2)
- Wider area
- Na h-Eileanan Siar
- Guarantee
- 12 months on every job
- Price
- A fixed quote before we start
- Telephone
- 01277 525 020
- Page updated
- 3 November 2026
How a job runs
Where the site stays busy, we agree a sequence with your contact so the disruption stays in one area at once. Each area is protected, prepared and sealed before we move to the next. Jobs near Knock are often grouped with others in the same area. Let us know if your dates have any give.
- First comes a look at the joints and, for older buildings, the asbestos records.
- The products and programme are set out in a fixed quote.
- We strip out the old sealant.
- Joint faces are cleaned, backed and resealed.
- We finish each building before moving to the next.
What we need from you
- Tell us which areas need to stay in use
- Let us know about inductions and permits
- Explain the parking and delivery arrangements
Getting a fixed quote
Pricing a project or setting a maintenance budget? We will quote against your scope and drawings that you can work with. If you have questions first, speak to us on 01277 525 020 or email the details over.
Related advice
What the job involves on each surface
Communal areas
Joints at low level in communal areas take knocks from bins, bikes and buggies, so they often need renewing sooner.
Tenement and older buildings
Stone needs a neutral-cure product and we choose accordingly.
Block-wide mastic in Knock
Knock sits close to the coast, within about 1 mile. Blocks and commercial buildings facing the sea take the most weather on their window perimeters and external joints, and they deserve more regular inspection. Being on an island, Knock means planning around ferry times as well as the weather. Photos of each elevation and a list of buildings let us plan the whole programme.
Around Knock, a planned programme renews failed mastic across a building or estate in one go. If you own or manage units on a site such as Parkend Industrial Estate (3 miles west of Knock), failed mastic on frames, door surrounds and external joints can be dealt with unit by unit.
Knock (Gaelic: An Cnoc) is in Na h-Eileanan Siar. Knock sits inside our coverage, and jobs here get the same fixed quote and 12-month guarantee as anywhere else. Across Na h-Eileanan Siar, 87 places are covered, including Knock.
Postcode districts covered here: HS2. We cover commercial and managed buildings on Seaview and A' Chnuic. You’ll find Knock on or near the A866. Just outside Knock, we also work in Na h-Eileanan an Iar (1 mile west), Aiginis (1 mile west), Lower Bayble (1 mile east), Garrabost (2 miles north-east) and Pabail Uarach (2 miles east). For island and remote sites, travel and materials need planning ahead, so include the location in your enquiry.
Near you in Knock
Nearby you will also find Western Isles Hospital (4.5 miles west).
Should maintenance staff do it?
What you see is the finished bead, but most of the work is hidden. Backing rod, primer where specified and a joint designed to move with the building are easy to get wrong without experience.
Some joints are best left to specialists: for example fire-rated seals that must match a tested detail, trafficked floor joints and external movement joints. A poor seal in places like these tends to cost more to put right later.
Also in Knock
Quoting for work in Knock
What shapes the price:
- The product specified
- Site requirements such as inductions and permits
- The size and state of each joint
- How much existing material needs removing
What a job costs comes down to how many linear metres there are, how much old material needs removing and how the joints are reached. Call for a fixed quote when you’re ready.
Before you send an enquiry
We can often quote from photographs and a few details. Please tell us:
- Photos of the joints, close up and from further back
- Drawings or a marked-up plan, if available
- Specification clauses that apply
- Your programme or deadline
Tell us about the building, the joints and when you need the work done, and a fixed quote will follow. To get it moving, phone 01277 525 020 or use the quote form.
When something else is needed
Being straight saves everyone time. New sealant won’t cure:
- Glazing that needs replacing
- Old mastic suspected of containing asbestos, which must be tested and dealt with by a specialist first
- Cracked or crumbling render, brick or stone at the joint edges (we will tell you if so)
If in doubt, phone 01277 525 020 or email us and we’ll say what we think before you book.
Surfaces we seal
- Communal entrances and stairwells
- Balcony and threshold joints
- Shopfronts below residential blocks
- Communal kitchens and washrooms
- Window and door perimeters on blocks
- External wall and movement joints
Common questions from Knock clients
Can being near the sea in Knock affect the sealant we need?
It can. Coastal exposure works external joints harder than inland weather. We choose the product for the exposure, prime where the manufacturer requires it and size the joint for its movement.
Does your area include sites such as Parkend Industrial Estate, near Knock?
Yes. Our area takes in Knock and its surroundings, with estates and business parks such as Parkend Industrial Estate included. To start, just phone 01277 525 020 or email us with the unit, the joints involved and your access times.
Can you send RAMS and CSCS details before starting?
Let us know your requirements: tell us what site paperwork you need (RAMS, insurance certificate, CSCS details) and we will confirm with the quote. We are CHAS accredited and a Constructionline member.
What will the job cost?
There isn’t a price list, as every site differs. Send photographs or drawings and we will price it at a fixed figure.
Do you cover Knock?
Yes. We take on work across Knock.
Can weather delay the job?
It can, for external work. Sealant won’t bond properly to a wet or frosty joint, so we watch the forecast and rearrange outside work if we have to. Internal work is far less affected.
Do you work for managing agents and housing associations?
We do. Most of our mastic sealing is for agents, factors, housing associations and portfolio landlords and work can be quoted per building or as a whole.
Why deal with it now?
Open external joints let water into walls and around frames. Damp patches, stained plaster and decorating claims can follow, which is harder to deal with than resealing. In Scotland, wind-driven rain finds a failed joint quickly, and for a smaller place like Knock, a repair visit takes planning, so it’s better to act early.
A quote for mastic joints depends on quantities, condition and access, and any specification that applies. Ask us for a fixed quote.
Why appoint us
- Standard and matched colours in many product ranges
- Fully insured
- Constructionline member
- Fixed quotes based on photographs, drawings or a visit
Read our cost guide and our accreditations.