Material guide · MCM
What is flexible stone, and what is it not
A mineral sheet about 3 mm thick that bends around a 200 mm pipe and still reads as quarried stone. It replaces 30 mm slabs where weight, curves or lifting gear were the problem. It is not structural, and it does not forgive being handled like tile.
The short version
Flexible stone is clay and mineral aggregate, formed at low temperature and locked together with an inorganic copolymer. The trade shorthand is MCM, modified clay material. There is no plastic core and no stone skin glued on top — the sheet is the same material all the way through, so a cut edge looks like the face. That one fact explains most of how it behaves on site.
A 1200 × 600 mm sheet weighs about 4.3 kg. Per square metre the material comes to 6 kg, against roughly 80 kg for 30 mm granite cladding of the same area. That ratio is the reason the product exists: it goes on upper floors, over old render and around columns without anchors, a crane or a structural survey.
- flexible stone panel
- flexible stone veneer
- flexible stone cladding
- soft stone panel
- MCM
Where it earns its place
Five reasons buyers pick it, in the order they usually ask.
One person can carry a day’s wall
A square metre of finished wall is 6 kg. The same area in 30 mm stone is around 80 kg, which means pallets, a hoist and a crew. On a fourth-floor renovation with no lift, the panel often wins on handling alone.
It wraps what stone refuses to
Round a 200 mm cylinder without cracking, tested to JG/T 311-2001. Columns, arched openings, curved reception desks and lift surrounds become ordinary work instead of a specialist subcontract.
Thickness you can actually specify
3 ± 0.3 mm on 1200 × 600 sheets, 4 ± 0.5 mm on big panels. The 2–3 mm material quoted elsewhere looks fine in a sample book and chips at the edge in the carton. Thickness is the margin that absorbs handling. Our engineer sets out the reasoning in five technical checkpoints.
It survives a facade
Twenty freeze-thaw cycles and −40 to 80 °C cycling, no cracks or bubbles at either end (ASTM C1026). Exterior walls, high-rise cladding and cold-store corridors are all in scope.
A utility knife is the whole tool kit
Score, snap, fit. No wet saw, no dust extraction, no blade wear on mineral. On site that difference shows up as a faster programme and a cleaner handover.
Where it is the wrong material
Three cases where we talk buyers out of it.
As the only waterproofing over a live crack
Water absorption is 5.41% by ASTM C97. Low enough to sit on an exterior wall with a drained, sound substrate behind it; nowhere near a membrane. If the wall is already letting water in, fix the wall.
On floors, worktops and stair treads
500 abrasion cycles cost the surface 0.0833 g (ASTM D1044). Fine for a wall that gets brushed past, wrong for anything that takes foot traffic or a knife.
Where a book-matched slab is the design
Patterns repeat every 1,200 mm. On a twelve-metre wall you either plan the layout or you see the join. If the drawing calls for mirrored veining across a lobby, this is not that product.
The weak point in service is the edge, not the face. Thin edges bruise on site and show every knock at eye level — which is why we run 3 mm rather than 2.
Against 30 mm natural stone
| Property | Flexible stone | 30 mm natural stone |
|---|---|---|
| Weight per m² | 6 kg | ~80 kg |
| Thickness | 3–4 mm | 30 mm |
| Fixing | Tile adhesive | Anchors and mechanical support |
| Minimum radius | 200 mm | None — it cracks |
| Cutting on site | Utility knife | Wet saw |
| Movement joints | Not required on standard walls | Required |
| Freight | About one-thirteenth the weight | Heavy freight, crated |
Specifications
- Sizes
- 1200 × 600 / 600 × 3000 / 1200 × 2400 / 1200 × 2800 / 1200 × 3000 mm
- Thickness
- 3 ± 0.3 mm standard; big panels from 4 ± 0.5 mm; 3D relief 5–15 mm
- Weight
- From 6 kg/m²
- Textures
- Slate, sandstone, marble, travertine, wood grain, metal
- Fire class
- EN 13501-1 A2-s1,d0
- Form
- Flexible sheet, carton or plywood crate
What the lab measured
| Test | Result | Standard |
|---|---|---|
| Apparent density | 1.92 g/cm³ | ASTM C97/C97M-15 |
| Water absorption | 5.41% | ASTM C97/C97M-15 |
| Flexibility | Surrounds a φ200 mm cylinder | JG/T 311-2001 |
| Freeze-thaw | 20 cycles, no breaks, cracks or bubbles | ASTM C1026-13 |
| Temperature cycling | −40 to 80 °C, no change | ASTM C1026-13 |
| Abrasion | 500 cycles, 0.0833 g mass loss | ASTM D1044-13 |
| Surface impact | Grade 7 hardness | ISO 10545-5:1997 |
| Prop 65 | Lead (Pb) not detected | CPSC-CE-E1002-08.3 |
| VOC | 54 substances tested, none detected | US EPA 5021A-2003 |
| Fire resistance | Class A2-s1,d0 | EN 13823 |
Report numbers and the PDFs are on the certificates page. If a specifier needs a specific clause quoted, ask and we will send the page.
How it goes on
The adhesive does the work. There is no anchor, no rail and no cavity, which is why the wall behind matters more than the panel in front.
- 01
Clean, dry, flat. On a renovation this is the slowest part of the job, and the part that decides whether the finished wall reads flat under raking light.
- 02
Adhesive spread evenly across the back with a notched trowel — standard construction adhesive, no specialist primer on sound substrates.
- 03
Press the sheet on while the adhesive is still open, adjust the position, then leave it alone.
- 04
Seal the edges and any joint that will see weather. Interior joints can be tight.
The step-by-step version, including the mistakes that cause callbacks, is in the installation guide, with a video walk-through.
Where it ends up
The same material gets specified for quite different reasons depending on the market.
North America
Commercial interiors, retail and residential renovation. Lightweight matters less than speed here — the panels go up over existing finishes without a demolition phase.
Europe
Older buildings that cannot carry 80 kg per square metre. Renovation work where the facade has to change appearance without a structural upgrade.
Middle East
Hotels, malls and hospitality fit-outs. Marble and decorative finishes, with the A2-s1,d0 fire class as the entry ticket.
Southeast Asia
Residential towers and interior work. Humidity resistance and the absence of heavy fixing detail drive most of it.
Questions that come up before the first order
Are flexible stone panels waterproof?
No, and any supplier who says otherwise is overselling. The sheet absorbs 5.41% water by ASTM C97 — low enough for an exterior wall with a drained, sound substrate, nowhere near a waterproof membrane. Treat it as the finish, not the weatherproofing.
Can it be used outdoors?
Yes, with that caveat. Twenty freeze-thaw cycles came back clean, and the panels went from −40 to 80 °C without cracking or bubbling. Twenty cycles is roughly twenty winters where the test ran.
What fire class is it?
EN 13501-1 A2-s1,d0, tested to EN 13823. Limited combustibility with minimal smoke — the class most commercial interiors specify. It is not A1.
How long does it last?
The lab measures cycles, not years, so be suspicious of anyone quoting a lifespan. Twenty freeze-thaw and 500 abrasion cycles are proxies. In service, what ends these panels early is a wet substrate and edge damage, not the material ageing.
Can it wrap a curved surface?
Around a 200 mm cylinder without cracking, per JG/T 311-2001. Tighter than that you are into relief panels and segmenting, which is a different conversation.
Does it look fake up close?
The stone series is pressed from mineral aggregate, so the surface has depth and shifts from sheet to sheet. The printed series is flatter by nature. Either way, see a physical sample before committing several thousand square metres — photographs flatter everything.
Ask for a sample, not a brochure
Samples ship with the matching test reports attached, so the numbers and the surface arrive together. Tell us the wall and the market and we will point you at the series that fits — or say if none of them do.