Shetland Islands · Scotland
Gremista Window Mastic
Professional window mastic in and around Gremista, with old sealant always removed completely.
- Untidy mastic left by window fitters
- Black, perished sealant on frames
- Water coming in at the bottom corners of a door
DIY sealant or a professional job?
The difference is mostly in the preparation and the product. We take joints back to clean, dry surfaces, and the sealant is chosen for how the joint moves and where it is, then guaranteed for a year.
Overfilling a joint is a classic DIY mistake. A thick, smeared bead looks untidy and doesn’t move well, and the joint depth matters as much as the finish.
Window mastic in Gremista
Whether it’s one leaking patio door or every frame on the house, you will get a clear quote before we start. Just send an email to info@mrmastic.co.uk and tell us how many frames there are and how they’re reached. Typical jobs include leaking joints at the ends of sills and old mastic that has gone black or come away, on uPVC windows, composite doors and timber windows & doors.
In and around a place like Gremista, homes range from older stone-built cottages to newer houses. Exposed frames and sills take the full force of wind-driven rain, so the mastic there works hard.
All of our work is guaranteed for twelve months.
- Location
- Gremista (ZE1)
- Wider area
- Shetland Islands
- Cover
- 12 months on all our work
- Quotes
- A clear quote up front
- info@mrmastic.co.uk
- Page updated
- 26 October 2026
The process
There’s no need to move everything out before we come, just the space around the work. Everything nearby is protected, and the job takes a few hours for a handful of frames, longer for a whole house for a typical job. Somewhere like Gremista may be a longer drive, and the journey is planned ahead. Tell us about tracks, gates, a ferry crossing or anything unusual about getting there.
- Each frame is looked over and we agree which ones need resealing.
- The old mastic is cut out and scraped back to clean surfaces.
- Deep gaps get closed-cell backing rod to set the depth.
- A flexible exterior sealant is applied in a colour to suit the frame.
- We tool each bead neatly and check every joint is closed.
Preparing for the visit
- Plan for the work area to be out of bounds to pets and children
- Mention any tricky access
- Mention any leaks or damp you’ve noticed
Ask for a quote
Getting a quote is simple: let us know what needs doing and where and its rough size. Photos by email help us understand the job, and we will take it from there.
Read more
Common questions in Gremista
Will you come out to Gremista?
Yes. Gremista is within the area we cover, which takes in towns, villages and rural addresses. We work across all of Scotland, including the islands, where work is planned around ferry crossings. Just mention lanes, gates or anything else about the route when you book.
Is window mastic in a coastal place like Gremista any different?
Coastal weather is harder on outside sealant: there’s more wind-driven rain and, closer to the shore, salt in the air. The right product, a clean joint and the right depth all help it cope.
Do you guarantee window mastic?
Yes. Our one-year guarantee covers every job, inside or out.
What information do you need?
Only a few details: the address or postcode, what’s wrong and any access issues. Then send an email to info@mrmastic.co.uk.
Are you ARBOMaster approved?
Yes. ARBOMaster is the approved applicator scheme for Arbo sealants, and we’re part of it.
Can I paint over the new sealant?
Not usually, if it’s silicone. We choose the product with your decorating in mind, so mention it when you book.
Do the sealants smell?
There can be a smell while the sealant cures. Opening a window helps.
Can you do the inside joint as well?
Yes. Plenty of draughts come through the inside joint as well as the outside, so sealing both is often worthwhile.
Other services in Gremista
Different surfaces, different methods
Aluminium frames
Bi-fold and sliding aluminium doors have long frame joints, and the threshold joint takes a lot of water. Each is cleaned, backed where deep and resealed.
Timber windows & doors
Wood swells when it’s wet and shrinks when it dries, so the joint must stay flexible. We seal onto sound, dry paintwork or timber.
Landlord and commercial work in Gremista
Whether it’s one flat or a portfolio, the work is the same standard: old sealant fully removed, joints prepared properly and a 12-month guarantee.
Mouldy or split sealant often shows up at the end of a tenancy, and it’s quick to put right between tenancies. Several properties can be quoted together.
What sealant work cannot fix
To be straight with you, some problems need a different trade:
- Damp coming through the wall itself rather than the frame joint
- Soft or decayed wood in the frame
- Misting between the panes of a double-glazed unit (that needs a new unit)
If you’re not sure, just send an email to info@mrmastic.co.uk and we will give you a straight answer before you book.
Where we work in Gremista
- Composite doors
- uPVC windows
- Window sills
- Aluminium frames
- Timber windows & doors
- Patio & French doors
What affects the quote in Gremista
Your quote is based on your job. We take into account:
- Which sealant suits the joint
- How much old sealant there is and how hard it is to remove
- Any working-time requirements on site
- Mould in or behind the old joints
The cost reflects the work involved, not a rough estimate. That is why we ask about the job first and agree the price before starting.
What to tell us for a quote
To help us quote quickly, let us know:
- If someone has resealed it before
- The problem you’ve noticed
- A few photos by email, if you can
- Any access issues, like height or stairs
Need a quote? Please send an email to info@mrmastic.co.uk and tell us about the job. We will explain what we’d do and send you a clear quote before we start.
Frames and glazing around Gremista
Gremista is within about 1 mile of the coast, where wind-driven rain is a fact of life and, nearer the shore, so is salt air. That’s hard on the mastic around window and door frames, especially on the side facing the sea. Work on the islands has to be planned around ferry crossings and the weather, so the more notice, the better.
For site and facilities teams at buildings such as Anderson High School, larger buildings have plenty of frames, and the mastic around each one ages. For an older house near a landmark such as St Margaret's Roman Catholic Church, frames set in older brick or stone need a sealant that suits the wall as well as the frame.
Gremista is about 1 mile north of Lerwick, in the Shetland Islands. Wherever you are in the ZE1 postcode area, our applicators can take on window mastic. Gremista is one of 63 towns and villages in the Shetland Islands we cover for window mastic.
We cover every part of ZE1 for window mastic and the streets around it. Whether your property is on Gremista Road, Arlanda Yard and Holmsgarth Brae or a nearby road, we can help. Close by, we work in Heogan (1 mile east), Lerwick (1 mile south), Sound (2 miles south), Gunnista (2 miles east) and Veensgarth (2 miles west). Island and remote addresses take a little more planning, so tell us where you are when you ask for a quote.
Near you in Gremista
Locally, jobs take us to homes and businesses close to Gilbertson Park, among other places. Other landmarks nearby include Montfield Hospital (1.2 miles south) and Shetland Textile Museum (within half a mile south). The countryside around Gremista includes Loch of Kebister and Setter Hill.
Why deal with it now?
Once mastic fails, rain can get between the frame and the wall. Over time that can mean damp patches, damaged plaster and rotting timber. Resealing now is a small job by comparison. Exposed walls in smaller Scottish places take a lot of wind and rain, and damp in stone or harled walls takes a long time to dry once water gets behind a joint.
Homes and businesses are quoted the same way: how much there is to do, how we reach it and what it needs, along with when we can work on site. Ask us for a quote and we will go through it with you.
Why us?
- Every job guaranteed for a year
- Approved under the ARBOMaster scheme
- We never seal over old sealant
- Full insurance on every job
Take a look at how sealant jobs are priced and customer reviews.