Are your masonry walls reinforced?
Unreinforced masonry used to be a common form of wall construction in Wellington and the Wairarapa. Unreinforced brick and masonry walls are very likely to collapse in a big earthquake. The following pose the greatest risk:
- Old double brick walls (two rows of brick with a gap between but no timber frame) image
- Concrete block walls with no steel reinforcing inside
If you have a more recent brick house, your masonry is likely to be a veneer – the brick wall is tied to a timber frame behind it. These perform much better in earthquakes.
- Was your house built before 1950 and does your house have external brick or block walls? If so, you probably have unreinforced masonry walls.
Consult a professional engineer for advice on reinforcing or replacing any unreinforced brick or masonry walls.
Do you have properly fixed wall linings?
Properly fixed plasterboard linings will add structural stiffness and strength to your house. However, old Wellington homes sometimes have wall linings of lath (wooden strips) and plaster or scrim (a coarse jute fabric) that has been tacked or stapled on to thin wooden planks (sarking). These old wall linings should not be relied on to provide bracing.
- Do the edges of a removed power point or light switch have lath (wooden strips) under the plaster or scrim (a coarse jute fabric)?
It can be difficult to tell if your house uses old linings. You may need to get advice.
Reline your walls with plasterboard. Either remove the existing lining and replace it with plasterboard or apply new plasterboard directly over the old lining, taking care to fix it properly to the framing behind.
These are both big jobs. Ask a professional for advice on how to best remove your old lining and install new plasterboard to provide good bracing.