Wall finishes
Microcement On Walls: Coverage, Sheen And Scale
Walls are where microcement is at its most forgiving structurally and its least forgiving visually. There is no traffic load to worry about, but there is nowhere for a trowel mark to hide on a five metre elevation lit from one side.
Wall finish questions
Substrates that suit a wall application
Plasterboard, skimmed plaster, tile backer board, existing tiles and sound masonry all take a wall system, each with its own primer. The most common problem is not the material of the wall but the flatness of it. A trowelled finish at two millimetres does not straighten a wall, and a wall that undulates will still undulate under a beautiful surface.
Board joints and any junction between two different substrates need meshing at base coat stage. That includes the line where plasterboard meets masonry, which is a classic location for a hairline to appear months later on an otherwise perfect elevation.
- Plasterboard
- Suitable, joints meshed, primer matched to the board
- Existing tiles
- Suitable where firmly bonded, joints filled
- Masonry and render
- Suitable when dry, sound and free of salts
- Timber panelling
- Case by case, movement is the deciding factor
Sheen and light do more than colour
The same pigment finished matt and finished satin will read as two different colours in the same room. Matt absorbs, softens and hides marks. Satin reflects, sharpens the trowel movement and cleans more easily. In a hallway that takes shoulder contact, the cleanability of a satin finish often beats the softness of a matt one.
Side lighting is the honest test. A wall washed by a window or by a downlight close to its face shows every variation in the trowel work, which is either the point of the finish or the thing that will irritate the client, depending on expectations set beforehand. On a large elevation we would always recommend seeing a sample panel on that wall rather than a board in a different room.
Working at scale without visible set lines
A microcement wall has to be completed wet-edge to wet-edge within a single working pass. Stop halfway across a long elevation and a set line appears where the two passes met, permanently. On a large wall that means enough applicators on site to complete the elevation in one go, which is a resourcing decision made before the job starts, not on the morning.
Where a stop is genuinely unavoidable, it should be designed in as a deliberate break at an architectural line, a shadow gap or a corner, rather than left to fall wherever the day ended. Designers can help enormously here by giving the applicator a logical panel arrangement to work to.
- Plan each elevation as a continuous pass before mobilising
- Design deliberate breaks at corners or shadow gaps, not mid-wall
- Match the crew size to the wall area, not to the room count
- Agree the sheen on a panel on site, in the room's own light
Durability in circulation spaces
Sealed wall finishes handle wiping, cleaning and everyday contact well. Where they suffer is impact: a trolley in a commercial corridor, a bike handlebar in a hallway, a chair back against a dining room wall. The finish is thin, so a sharp impact damages it in a way a solid plaster would shrug off.
In busy commercial circulation, the sensible approach is to accept that and detail for it, with a more robust material at the impact zone and microcement above it. On a private house it is usually a non-issue, and localised repair is possible although a repair to a hand-trowelled surface is never entirely invisible.
See it on the wall before you commit
Elevation size, lighting and sheen decide how a microcement wall reads far more than the pigment reference does. We can prepare sample panels for the actual wall so the decision is made in the right light rather than in a showroom.