Plastering advice
Why Does Plaster Crack?
Short answer
Plaster cracks most often because of normal building movement, drying shrinkage, vibration, or a junction between two different materials. Fine hairline cracks are usually cosmetic and can be filled or skimmed over. Wide, stepped or rapidly growing cracks should be looked at before any plastering.
Common causes
In houses across Sutton and South West London these are what we see most.
- Seasonal movement, particularly on clay subsoils
- Shrinkage as a new building or extension settles
- Junctions between plasterboard and solid wall, or old and new work
- Ceilings flexing between joists, especially above traffic areas
- Vibration from doors, stairs and busy roads
- Previous repairs that were filled rather than properly bridged
Cracks worth investigating
Get advice before plastering if a crack is wider than a couple of millimetres, runs diagonally from a window or door corner, steps along mortar joints, or reappears quickly after being filled. Plastering over a live structural issue only hides it temporarily.
How they are repaired properly
A lasting repair means opening the crack up, treating the cause where possible, bridging the joint with scrim or mesh, and then skimming the surface so the repair does not show through the paint.
Need this doing?
SJF Plastering covers Sutton, Surrey and South West London. Call 07967 302162 or message us on WhatsApp for a free quotation.