Sand and cement render can look fine from the pavement while hiding hollow sections underneath, and coating over a hollow patch does nothing to stop it eventually falling. A proper tap survey before specifying anything is not optional here.
A tap survey across the whole elevation identifies hollow sections, which we then repair before any coating goes on top.
No — fine surface crazing is common and usually cosmetic, while wider stepped or diagonal cracks warrant a closer look before proceeding.
Yes, we check the render type where we can and specify a compatible system rather than defaulting to one product for every wall.
Tapping the render systematically with a hammer handle reveals hollow-sounding areas where the bond to the substrate has failed, even where the surface shows no visible crack. Those areas need cutting out and re-rendering, not just filling and coating over.
Fine, map-like surface crazing is usually cosmetic and copes well with a high-build coating. Wider, diagonal or stepped cracking can point to movement in the structure behind the render, which is worth a second opinion before any coating goes on.
A traditional cement render and a modern polymer-modified render do not always want the same coating system, since their flexibility and porosity differ. Checking which type is present, where possible from records or by testing, avoids specifying a coating that fights the substrate underneath.
Ask for a tap survey of your elevation before committing to a full repaint specification.
Render needs a proper tap survey before coating, since hollow or moving sections need repair, not paint.
Speak to a Hampshire commercial decorating contractor that turns up, communicates clearly and delivers a finish that lasts.
