Lath and Plaster: Repair or Replace?

Many South London Victorian and Edwardian homes still have their original lath and plaster walls and ceilings. When problems arise, the question of whether to repair or completely replace it is a significant one.

What Is Lath and Plaster?

Lath and plaster is a traditional wall and ceiling construction method using thin strips of wood (laths) nailed across joists or studs. Three coats of lime plaster were applied over the laths. The first coat (the render coat) was pushed through the lath gaps to form 'keys' that held it in place.

Signs It Needs Attention

• Hollow sound when tapped (lost key)
• Visible cracking, especially at corners
• Sagging ceiling sections
• Crumbling plaster

Repair: When It's Appropriate

Repair makes sense when: - The laths are still sound - Only isolated areas have lost their key - You want to preserve the original character and period detail - The surrounding plaster is in good condition

Repair involves cutting out the damaged section, checking the laths, and applying new plaster matched to the original.

Replace: When It's Necessary

Replacement is the better option when: - Large areas have lost their key and are unstable - The laths themselves are rotten or infested - A ceiling has been affected by water damage or has sagged significantly - You want a perfectly flat, modern finish

Replacement typically involves removing the lath and plaster and installing plasterboard, which is then skimmed.

Heritage Considerations

In conservation areas or listed buildings, maintaining original materials may be a planning requirement. Lime plaster can be specified for repairs.

Shadbolt Plastering carries out both lath and plaster repairs and replacements across South London and Surrey.