Five signs your external render needs attention

Cracks, hollow patches and staining can all tell a different story. Here is what to notice before problems spread.

Cracks that are changing

Fine shrinkage cracking is different from a crack that widens, returns after filling or follows a structural junction. Photograph and date anything that appears active.

Hollow-sounding areas

A dull or hollow sound can indicate a loss of bond between layers or from the wall. The affected area may extend beyond the visible defect.

Persistent staining

Dark runs, algae or staining below roof edges and sills often point to water being directed onto the façade. Cleaning alone will not correct the source.

Bulging or loose edges

Movement around corners, beads, plinths and service penetrations deserves prompt attention because exposed edges can allow further water entry.

Repeated internal damp at an external wall

Render can be one factor, but damp has several possible causes. Gutters, ground levels, ventilation and plumbing should be considered before assuming the façade is responsible.