Underpinning Methods

Comparison of Underpinning Methods

Traditional Concrete Underpinning Methods Compared with Uretek’s Modern Technology

The Uretek Underpinning Method is :

Traditional Concrete Underpinning is :

Amazingly fast. Most jobs take between half a day and two days.

Very clean and neat. There’s no excavation, no cement or concrete, no water.

Very unintrusive. No need for occupants to move out. Usually not much furniture to move. Injection done from outside wherever possible. Injection through tiny holes that can usually be placed between tiles or even through carpet. Very little to get in your way while the work is being done.

Very slow. Most jobs take between two and three weeks

Extremely messy. There’s a great deal of excavation, concrete and water. And the excavated material has to be dumped somewhere, usually across lawns, paths and garden beds. And it’s often walked into your house.

Hugely intrusive and stressful. Experienced occupants often choose to move out. Interior work usually needs furniture and carpets to be moved. The site typically resembles a war zone!

General Issues Affecting Underpinning Methods

In reactive clay conditions, foundation clay soils expand and contract with changes in the moisture content of the ground. (“Shrink-swell”) Concrete or masonry underpins, unless installed along every part of a building’s footing system, often contribute to future differential movements in the structure. This is because underpinning is generally used to re-support a footing down onto a different stratum not susceptible to movement. The problem is that whilst the corrected section is then effectively rigid, the adjacent sections that have not been underpinned will continue to move with future shrink-swell of the ground. This can create new cracking in the structure - unless articulation joints are sawn completely through the walls.

Uretek resin injection underpinning method does not exhibit this problem. This has been shown by empirical evidence, (university research and nearly 30 years of specific field application). Uretek is different, addressing the nature of the foundation soils and any cracks and voids therein, improving bearing capacity, raising and restoring and maintaining a uniformity of bearing strata.

N.B.: In relation to concrete underpinning, Australian Standard AS 2870 warns, “Underpinning should generally be avoided where the problem is related to reactive clay,” and “Deep underpinning should only be considered as a last resort.”

In poor ground conditions (eg non-cohesive, sandy or muddy soil or poorly compacted fill) where there is settlement, the added weight of concrete/masonry underpinning (2400 kg/cu.m.) can exacerbate the situation, not correct it. With Uretek underpinning methods and the exceptional specific rigidity (stiffness to weight) of Uretek material, this is avoided.

A Comparison of Underpinning Methods shows that Uretek 'keyhole surgery' offers many advantages over the old-fashioned underpinning methods.

Uretek Ground Engineering

Uretek solves many problems by unique and patented systems of resin injection.

Fast, economical, long-lasting, environmental and with minimal disruption.