thisplace.com.au - Foundations and Footings

Many serious foundation problems are caused by reactive soil types and trees and gardens being planted too close to the house.

Most clay soils are 'reactive soils'. However, professional advice should be sought from either your builder or soil engineer. Your Local Government building section may also be able to advise you about soil characteristics in your area.

Large trees use huge amounts of water and can very quickly draw moisture out of the ground during dry periods. This results in destabilised moisture content of the soils around your home and ultimately can cause a foundation problem.

Overwatering gardens around your home can have the opposite effect. This changes the moisture content of clay, which can result in the heaving of foundations adjacent to the garden.

When watering around your home you should avoid 'ponding' of water in a particular area as this also affects the moisture content of the soil, which in turn can cause damage to footings and foundations.

Remember, too much or too little water near the perimeter of your home can cause serious problems with foundations and footings.

Damage to foundations and footings can cause major structural problems, resulting in costly repairs.

Hints for avoiding problems and costly repairs:

Water evenly around your home and don't overwater
Ensure the ground is graded away from the walls of your home, and that your property has adequate drainage
Promptly repair broken downpipes, leaking taps, sewerage pipes and other water services
Toilet cistern overflows and hot water system overflows should be directed away from the immediate area adjacent to the foundations and those services maintained to ensure excessive leakage does not occur
Garden beds should not be located against the house
To minimise the risk of foundation damage, obtain professional advice when selecting and planting trees according to their mature height and root structure (on normal suburban blocks of 600 - 800 sq.metres, trees that grow higher than 8-9m would usually be inappropriate.

For more information contact the Building Services Authority or go to their website.

Source: BSA Fact Sheet Edition 2 9/99