Is it really worth the risk?

Non-compliance could cost someone big dollars! Don't let it be you!


Ask to see the soil report before commencing any drainage project and if flexible connections are specified in the storm water and sewer drainage section, comply with the recommendations to prevent future reactive soil damage.


These high performance, low cost fittings have been the key to success for Storm Plastics. This flexible fitting was developed at a time when engineers had been looking to solve problems caused by expansive soils. The Expanda Joint has proven to adequately satisfies engineers' requirements.

It is manufactured to tolerances that ensure maximum seal when installed correctly and is designed not to pull apart.

Differential Soil movement of up to 150mm, is accommodated by the 100mm DWV fitting and the 90mm Stormwater fitting accommodates up to 90mm of soil movement.
Mechanical Flexible Joints are currently being called up by consulting engineers to the building trade, in an effort to reduce the likelihood of structural damage in reactive clay sites.

It is now mandatory that Mechanical Flexible Joints are installed in all sewer and stormwater drains in reactive soils.

Expanda Joints may be installed vertically or horizontally in reactive soils classification and have been designed as mechanical  flexible couplings in keeping with the requirement of AS 2870-2011. Connection of stormwater drains and waste drains shall include FLEXIBLE CONNECTIONS on reactive sites classified as H1, H2 and E.

The 100mm DWV Expanda Joint is manufactured to comply with AS/NZS 1260. It has been tested at a registered NATA Laboratory and has been authorized by the relevant authorities throughout Australia.
The 90mm Stormwater Expanda Joint has passed similar tests, but comes under local government/council jurisdiction.


Important Advice
The Expanda Joint, being a Mechanical Flexible fitting, does need extra care and attention for maximum performance. Installation instructions on the fitting should be followed.
During development of the Expanda Joint, it was found that the 100mm fitting, if left in a completely closed position, was very difficult to open. Hence the addition of the cardboard spacer, easily removed by pulling one end of the spacer, until it is out of the fitting.

The rubber ring seal below the cap grips so tightly on the pipe that physical pressure is insufficient to release the seal when the fitting is completely closed. However, the contractor may be assured that once the fitting is installed underground, soil movement, which is great enough to break solvent cement joints, will certainly expand and contract the Expanda Joint as necessary.

Before use, the spacer should always be left in the fitting. If the spacer has been removed, however, the fitting should be stored open by at least 20mm. To free the seal tension, one can simply remove the cardboard spacer, upturn the fitting and push sharply downwards, or alternatively 'stomp' on it. Once the seal has been released, the fitting becomes pliable for use.

All units with this cardboard spacer should be treated in the same manner


Advantages for DWV Application
The pipe and socket of the Expanda Joint are moulded to tolerances that ensure maximum seal is attained (unlike the elastic band, clamp and slip socket methods).
Only one Expanda Joint is required, therefore the time saved on installation is a cost saving.
Use of the Expanda Joint achieves a permanent repair and incorporates allowance for future soil movement.
Expanda Joints are easy to install in confined space's.

The fittings are designed to resist penetration by roots. 100mm Expanda Joints are assembled using a 7mm face rubber ring seal which is manufactured in accordance with AS 1646 and the snap-on cap has been designed primarily to deter root intrusion.


Tension Free Sewer Pipe Systems
One of the key objectives in designing, engineering and installing an Expansion Joint is to minimize soil tension on the drainage system.

The SWIVEL EXPANSION JOINT is capable of being angled in all directions by up to 15 degrees from its axis and has a telescopic ability of 50mm. When coupled with Storm Plastics EXPANDA JOINT it provides the Engineer with the means to design and overcome all tensions in reactive soils.

The SWIVEL JOINT adds to the range of specialised plumbing fittings available from all good Plumbing merchants and has been tested and approved for use in Europe and South Australia. S.A test cert. No. LR18.

The 100mm SWIVEL JOINT can extend 50mm and the 150mm SWIVEL JOINT can extend 60mm, thereby compensating for soil movement.


Soil Classifications


 AS 2870-2011 Ref Table SP-1


A - Moist Sand & Rock Sites   0-10 mm


S - Slightly Reactive Soils  11 - 20 mm


M - Moderately Reactive Soils  21 - 40 mm


H1 - Highly Reactive Soils  41 - 60 mm


H2 - Very Reactive Soils  61 - 75 mm


E - Extremely Reactive Soils  76 mm  +


P - Site condition affected by various and abnormal conditions/features



Beware of Sodic Soils


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