Early warning “leaky” signs for home owners and developers in case your builder/architect/supplier has dumped you in it’

Posted on Thursday, November 19th, 2009 at 3:13 pm in

Some key factors to observe and to get right on any home:

• ‘Good boots’ and ground clearance. A well built and maintained house has all ground-water deflected away and cladding well clear of wet ground. As a guide, a brick breather-slot should be 250 mm above wet ground.
You wouldn’t like living with wet feet – neither does your home.

• If the ‘hat’ fits: roof flashings. A well-built home has the metal flashings turned out to deflect water into the gutter and the cladding clear of the flashings. As a guide, cladding should be at least 30 mm off the roof and the metal flashings turned out, so water deflects into the gutter.
You wouldn’t wear your hat upside down – neither does a house.

• Deck edges. Water needs to be correctly deflected and plaster not able to ‘wick’/draw-up water from a deck. As a guide, water must be turned out.
Imagine if you got a hose and directed it at this point: if water can get in so can rain.

• Cracks and wildlife. Well-maintained homes are dry and it is very rare for ants to visit and colonise in the walls. Ants look for water. If they are getting into the cracks and under the cladding, chances are your house has serious leaks in the walls.
Larger cracks often signify abnormal movement of timber frames behind the cladding, meaning the building may have settled, or the framing has in part begun to rot.

• Mouldy curtains and linings. Well-ventilated rooms allow internal moisture to escape. The Building Code states one air change per hour is required. Excessive internal moisture allows mould to grow on curtains and on much of the internal furniture as well.
Many mould species carry warnings that the spores they produce affect breathing and may bring on asthma attacks and prolonged periods of sickness.

• Window flashings. Well-flashed windows rarely leak or cause damage. Proper sill flashings, with turned up ends and sealant positioned at the ends to turn water out, are what’s needed.
If a crack develops it will most probably allow water in behind to rot framing.

• Parapet caps. A metal cap turned up at the wall prevents water getting in behind the cladding. Cracks where the cladding meets the house probably mean water is getting in and will cause significant damage — if it has not already happened.
The timber should be checked and correct water deflecting flashings used in its place. Plaster caps do not work.

• Gutters. Well-fitted outside gutters can safely overflow outside the building, without doing any damage. Complex shapes inside some gutters have meant the gutter is cut away, allowing water to overflow onto the soffit (enclosed gutters) where it often gets into the wall and behind the cladding, causing the timber to swell and crack the outside plaster and the interior linings around window openings, as well as rotting the framing.
Take a look at your gutter. If you can’t see a rounded shaped channel on the outside, then you will have an enclosed gutter which if clogged with grass/leaves/plastic bags/etc, so that water is restricted in heavy rains, or has been left without maintenance, will overflow into your ceiling — this is a no-brainer.
• Corner windows. A sill tray under a mitred window frame prevents water seeping back to the timber frame. Stains in a corner window indicate the corner is weeping and it’s highly likely the framing is wet and potentially rotting.
These areas can be surveyed non-destructively with moisture probes.

Timber penetrations through cladding. Correct flashing will deflect water from getting behind the wall cladding. A big overhang (soffit or eave) will reduce the chances of rainwater getting in. Timber beams that penetrate wall claddings need more than expert maintenance — in all probability they need to be