Avoiding cracks

By Alex May

What do homeowners need to know if we are lucky enough to get some cloud juice back into our parched soils?

My house is hurting. “Water,” the walls seem to whisper at night. “I need water.” Houses are literally cracking up under the extended dry period the drought has brought on – Archicentre says 34 per cent of Sydney homes have cracked during the drought as clay soil shrink and contract. Fine cracks along cornices and doors that don’t shut properly are the minor symptoms of drought-induced house movement – whopping great holes in the walls are the big problem. But those dry soils could get the big long drink they’ve been crying for in March 2007.

If you can interpret Bureau of Meteorology-ese, you will know that El Nino is weakening and March is typically the highest rainfall period for the Sydney area. “There is a 50:50 chance of rainfalls returning to averages,” is the official line from the Bureau. (That means we have an average chance of rainfall returning to averages, rather than the sub-averages we have been enduring for the last few years. Geddit?) Homeowners may rejoice at such news, but they need to understand what a return to average rainfall could mean for their parched property. Properties on shrunken, dried out soil are likely to shift again this Autumn, ideally with cracks closing up. Archicentre’s Angus Kell has been recommending that people do not repair any cracks until the rains return.

“Don’t spend any money on expensive under-pinning work or try to repair the cracks while the soil is still dry – wait until the rain and the cracks will probably close up,” he says. “Once that happens, it will mean a mini-boom in work to gap-fill the cracks, and repainting, and tuckpointing the mortar in brickwork. The tuckpointers will be very happy.”

Building inspector David Hall says older double brick homes have been the most susceptible to cracking – with an Archicentre report finding the upper north shore and inner west the most vulnerable areas. Property owners have been tempted to spend big bucks on underpinning to fix the unsightly cracking.

“It’s not worth spending the $80,000 on underpinning the foundations to stop cracking if it’s been caused by drought. Once the rain comes, the ground will shift again. If we return to drought, the cracks will come back,” he explains. “I’ve been recommending that people irrigate the foundations of their house.”

Hall and Archicentre both suggest setting up drip irrigation around the foundations of a home to stop soils shrinking in the dry period. So instead of watering the plants, you water your house. Naturally, once the rains return this can be stopped.

“There’s also work that can be done with trees close to the house. Tree surgery and occasionally tree removal can also prevent further cracking,” Hall says.

HERE COMES THE RAIN AGAIN (WELL, MAYBE)

Other checks to do before rains come include:

ROOF INSPECTION:

OK, don’t go clambering all over your roof and risk a fall but find a safe way to check the condition of your roof. Extended dry periods mean you are probably unaware of any leaks – and any new homes or renovations have possibly not been tested in heavy rains. If roof tiles look bleached or aged, they could leach water. Any cracked tiles can be swapped with an uncracked tile on the outer edge of the roof. Call in a roofing company if you suspect any leaks.

GUTTER CLEANING:

If the heavens open, the water will need a clear path to escape down the dusty downpipes – otherwise you could find yourself with some flooding or water in places you don’t want it. Clean all gutters and downpipes now. Kell also recommends that inner city dwellers check the condition of street gutters and storm water pipes. “There are lots of hard surfaces in the inner city, so drainage of stormwater is important. Don’t just check your own house, but also the surrounding properties and streets,” he says.

GET INSULATED:

Weather stripping can be plastic, foam, felt or metal and it seals small gaps around doors and windows, keeping moisture and cold air outside. On doors, make sure the bottom seal is working properly. Adhesive-backed foam pads are easy to install on windows to minimize drafts and reduce heating costs. With cooler months ahead, it’s worth checking a) whether you have any insulation; and b) whether it is in good condition. Patnicar’s Justin Beck – who specializes in supplying and installing insulation – says winter is his busiest time as people in old houses realise that insulation makes a home up to 10 degrees warmer in winter. The average cost is between $800 and $1200. The Building Code of Australia suggests a 2.5 rating for the Sydney area.

“It’s worth it to go above the minimum standard,” explains David Hall. “You pay the same labour costs whether you’re installing 2.5 or 3.5.” Beck says you can over-insulate a house, particularly if there are west-facing windows, so it’s worth getting a professional to quote and explain the best type of insulation for your particular property.

CLEAN HEATERS AND CHIMNEYS

Old houses with open fireplaces could need to make an appointment with a chimney sweep to not only clean out the chimney, but check it’s condition.

“The biggest problem I see in Sydney is erosion of the brickwork around chimneys,” says Hall. That means chimneys can come crashing down through the roof in heavy winds or storms. “A good chimney sweep will check that for you and advise you.”

People with combustion heaters can clean their own chimneys, and Hall recommends this tip:

“I unscrew the cowl on the top of the chimney, drop down some rope with a heavy screwdriver attached,” he explains. He then goes into the heater, ties a bottle brush to the end of the rope and pulls the brush up through the chimney. “That removes all the solids and resins from the wood. You need to do it once or twice each winter if you use a slow combustion heater,” he says.