Skip navigation

Roofs and walls

Your home is likely to be more resilient and safer in an earthquake or extreme wind if the roof is lightweight and well secured. This includes the roof being well connected to the walls and making sure the walls are safe and strong too.

How safe are your walls and roof?

  • Check your roof inside and outside. Does its material or condition create a hazard? Is there a header tank that needs securing or removing?
  • Can repairs be done to make your roof safer in the event of a natural disaster? If re-roofing, consider a lightweight material.    
  • Are your walls solid and reinforced? Unreinforced brick and masonry can be hazardous in a natural disaster.  

Check your roof

Find out about the basic checks you can do inside and on top of your roof, for all roof types. Only complete these checks if it is safe to do so. Otherwise, talk to a licensed building practitioner(external link) or an engineer to complete these checks for you.

Inside the roof

Find the access point to your roof space so you can check the condition of the framing.

  • If it’s a timber frame, look for borer or rot. If timber needs to be replaced, you will need a licensed building practitioner to do the work and may need a building consent.
  • Check that nails are in good condition and the timber isn’t split around the heads of nails.
  • If you have a steel framed roof, check for signs of rust or loose connectors.
  • If you have concrete, clay or slate roof tiles, make sure they are well secured to the framing so they don’t slide off in an earthquake.

Consider getting advice about whether the roof needs any additional bracing for extra strength.

On top of the roof

  • Make sure all materials are securely fixed down, and all nails and other fastenings are in place.
  • If you have a flat roof, make sure the fixings and the roofing material around the fixings are in good condition (no rust in the steel roofing or the fixings). Flat roofs may be more hazardous during a storm as the increased lifting forces of the wind can pull them off more easily than pitched roofs.
  • If you’re considering replacing heavy roof tiles, such as concrete or clay, find out about lighter weight metal options. You can get some metal roofs that look very similar to clay tiles.
  • Keep gutters clear of leaves or debris so water doesn’t overflow into your roof space, wall cavity or ceiling during heavy rain. Check your gutters if a volcanic eruption is predicted in your area, as ash build up could cause blockages.

You can read more about providing sufficient bracing capacity for wind and earthquakes in the bracing supplement on BRANZ’s Build Magazine website(external link).

Check your walls

Your roof needs to sit on external walls that will perform well under stress. Different types of wall construction behave differently in natural disasters.

In most cases, you will need a licensed building practitioner to help you check the walls and carry out any strengthening work.

Gable roof and brick walls

Check in the roof space to make sure the gable walls are braced, as they can cause damage if they fall during an earthquake. Check that the brick veneer is properly tied to the gable end framing.

Brick or block masonry walls

If your house was built before 1950 there’s a chance any external brick (such as double brick) and concrete block masonry walls are not reinforced. These are at  risk of being damaged in an earthquake.  

Brick veneer walls

These walls are less hazardous than brick or block masonry walls in an earthquake but some damage can still occur. The veneer could come off the timber framing if the ties have corroded or their fixings have weakened. The best time to check the ties or fixings is when you have the wall open for renovations. 

Lath and plaster walls

Houses built before the 1930s often have ‘lath and plaster’ wall linings. These are closely spaced horizontal thin timber strips covered with plaster. These types of wall linings are not intended to provide bracing in an earthquake.

Securing header tanks

header tank webIt’s important to check your roof space and secure heavy items you might not realise are there, such as a header water tank.

Older houses may have a header tank. This is a water tank in the attic, roof space, or on the roof, that feeds the hot water cylinder and helps manage the water pressure. The tank will be heavy especially if it's full, and could damage your home if it moves or spills in an earthquake. Make sure you fasten it so it doesn’t wobble, shift or even crash through the ceiling. Try doing the following:

  • strap the header tank to the ceiling framing
  • nail timber blocks to the platform at the base of the tank tray to stop it sliding
  • fit wooden blocks between the perimeter of the tray and the tank.

An empty and unused header tank is unlikely to cause any damage, but it’s a good idea to take it out of your roof space if possible. 

Working safely at heights

If you decide to go into or onto your roof, or undertake any inspection or work with walls that involves heights, make sure you do so safely.

Some key steps:

  • If you’re going up on the roof, check the weather and delay your inspection if necessary.
  • Ask someone to watch while you’re inside the roof or up top, and let them know which areas you’ll be inspecting. 
  • Check it's safe to work around any power services. If not, turn them off. 
  • Check your equipment is in good condition (for example, your ladder or torch).
  • Wear appropriate safety gear for the task, such as non-slip footwear, hard hat, high vis vest, gloves, mask, overalls, kneepads, boots and protective eyewear.

You can read more about working safely at heights(external link) on the Worksafe website.