than 3/16″Less than 3/16″
|General or partial movement of the background|
or the building.Thermal movement.Poor workmanship. Render too
thick. Too much water in mix. Over saturated
backgrounds. Insufficient setting
Bad preparation of background.Over saturated
|Check if movement is still|
active. (Engineer to
If building stable,
repair cracks / areas.Depending on extent, open
out crack and fill with same
Either apply slurry fill
|Poor background preparation. Poor suction control.|
background. Background too
smooth. Incompatibility with existing
Insufficient strength in bonding
coat. Background movement. Metal corrosion.Salt
crystallisation. Excessive or late trowelling.
|Repair or replace as appropriate.Consolidation|
by grouting may be considered.
background preparation.Incompatibility with existing background.Metal corrosion.
Frost damage during curing.
|Depending on the extent of damage, either|
partial repair or total replacement. Neutralise and treat any rusting metal.
|De-calcification of render (loss of binder). Poor background|
preparation. Poor suction control. Rapid evaporation of water during application,
( pror to adequate set). Frost damage. Insufficient binder dosage. Variation in
surface compaction / finishing. Poor sands.
|Partial or total repair with|
correct mortar applying due protection and following best practice.
|Poor background preparation. Weak mortars.|
repair. Light repairs with several coats of lime wash.Rectify detailing problems.
Replace if necessary.