What is vertinnen?
In construction, vertinnen is the Dutch term for applying a thin coat of cement mortar to a wall or floor, usually wet-on-wet, to stop moisture from penetrating inwards. The coat itself is called the vertinlaag. The second, more general use of the word is coating a metal object with a thin layer of tin, known in English as tinning or tin-plating.
Vertinnen of masonry
In the past, solid brick walls without a cavity were given this thin cement coat on the inside or outside to limit rain penetration. Walls and floors of wet rooms, cellars and the outer face of inner cavity leaves were, or sometimes still are, treated the same way. Sometimes the coat is roughened or scratched, so that a following plaster coat bonds better.
With modern cavity walls, such a coat is needed less often, because the cavity itself stops the rainwater. In practice, the coat is therefore often left out.
Related techniques
- Scratch coat (berapen): a rough first coat of mortar as a base for plasterwork.
- Cement rendering: finishing an entire facade with a cement coat, often also to give untidy brickwork a uniform appearance.
- Trass course: a water-repellent bottom zone in masonry against rising damp.
- Silicate painting (keimen): finishing a facade with a mineral silicate paint.
Tinning metal
A layer of tin protects metal against corrosion and makes it easier to solder. Tinplate is thin steel with a tin coating. Tinned copper is sometimes used as roofing and weathers grey instead of green. The ends of electrical wire are often tinned so that they make better contact and do not fray.
Tips and points of attention
- Watch out for moisture in old walls: a cement-rich coat on an old lime-mortar wall is harder and more vapour-tight than the masonry. Moisture can then become trapped behind it, causing frost damage and flaking plaster. For historic work, choose a lime-based or moisture-regulating finish.
- Prepare the substrate: make the wall dust-free and pre-wet absorbent masonry, so the mortar does not dry out too quickly.
- Do not confuse with impregnation: an impregnating agent soaks into the stone and does not form a layer; vertinnen is a coat of mortar.
Related terms
- Scratch coat
- Cement rendering
- Trass course
- Silicate painting
- Inner leaf of a cavity wall
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