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Silicone, monocouche and through-coloured render
Silicone and monocouche render costs £60 to £95 per square metre including scaffold. The colour is through the material rather than painted on, so it never needs redecorating, and that is most of the argument for paying more than sand and cement.
What this covers
What it costs. Silicone and monocouche render costs £60 to £95 per square metre including scaffold, against £45 to £75 for sand and cement. Full cost breakdown.
What the job covers
- Basecoat, mesh and topcoat over blockwork on a new build
- Recoating a tired sand and cement render with a thin-coat system
- Colour matching an extension to an existing rendered elevation
- Fitting a drip bead and a base track before the basecoat
- Applying a self-cleaning silicone topcoat to a north-facing wall
What is involved
A thin-coat system is a polymer basecoat with a fibreglass mesh embedded in it, then a coloured topcoat two or three millimetres thick. The mesh is what stops the cracking that sand and cement gets at stress points, and the silicone in the topcoat is what sheds water and keeps dirt from keying into the surface.
Monocouche is the one-coat version, a dry powder mixed on site and sprayed or hand-applied in a single pass to around fifteen millimetres. It is quicker and it is less forgiving: the colour is in the mix, so a batch difference shows as a band across the elevation and cannot be painted out.
Both need the wall underneath to be sound and reasonably flat, and both need beads at every edge. Neither is a repair for a wall that is holding damp. Thin-coat over a wet wall traps the water behind a waterproof skin, which is the same mistake as cement on a solid wall and shows up the same way.
Basecoat, mesh and topcoat over blockwork on a new build, one of the jobs a silicone and monocouche render specialist is hired for.
Choosing someone for the job
Ask which manufacturer's system it is and whether they are an approved applicator for it, because the guarantee usually depends on that. Ask whether the price is monocouche or a full basecoat, mesh and topcoat. Ask what happens at the damp proof course and at the window reveals. And ask to see the colour on a sample board in daylight, not on a screen.
Common questions
Does silicone render need painting?
No. The colour runs through the topcoat rather than sitting on it, which is the main reason people choose it over sand and cement. Expect to wash it down occasionally rather than repaint it.
What is the difference between monocouche and silicone render?
Monocouche is a single through-coloured coat, usually fifteen millimetres, mixed from a dry powder. A silicone system is a basecoat with mesh plus a thin coloured topcoat. The silicone one is more flexible and more forgiving of movement; monocouche is quicker.