Fantastic Plastic: Should I Choose A Concrete Or Polypropylene Soakwell?

4 August 2016
 Categories: , Blog

Incorporating soakwells into a home or farm's drainage system is an excellent way to regulate the drainage of stormwater away from your property. These subterranean tanks collect excess water and allow it seep slowly back into the surrounding soil, preventing soil waterlogging and excessive water run-off which can potentially lead to expensive fines and legal troubles.

Despite their effectiveness, these devices are remarkably simple, and you do not have many difficult decisions to make when choosing a soakwell beyond size and capacity. However, one important decision you will have to make is what your soakwell will be made from. Soakwell tanks are widely available in both concrete and polypropylene versions, and while both materials allow the soakwell to perform the same function, they each have their own distinct properties which may make them more or less suitable for your needs.

Concrete soakwells

In terms of raw durability, it's hard to beat concrete soakwells -- a well made and well installed concrete soakwell can be expected to last for decades, with minimal maintenance and oversight required. This durability comes with an enormous amount of load-bearing strength, and even the smallest and cheapest concrete soakwells can be expected to bear the weight of heavy vehicles and machinery passing overhead. In addition, the large, angled drainage outlets of concrete soakwells allow consistent and effective water drainage while minimising the risk of clogging and loose soil floating into the tank.

Unfortunately, concrete soakwells are as heavy as you expect any large, concrete tank to be, and transporting and installing concrete soakwells can be very difficult (not to mention expensive). Hiring professional soakwell installers is practically a must, and you may also be required to hire powered lifting equipment to transport the soakwell on-site (although many reputable soakwell installers will provide this machinery themselves). Concrete soakwells also tend to be significantly more expensive to purchase than equivalently-sized polypropylene soakwells

Polypropylene soakwells

These modern soakwells are built to a modular design that can be easily disassembled and reassembled. Combine this with polyproylene's light weight, and you have a soakwell that is tremendously easy to transport and requires little mechanical aid to install. Despite this lightness, however, polypropylene soakwells are surprisingly durable, and contain a number of additives to prevent perishing. As such, a polypropylene soakwell can have a comparable lifespan to a concrete equivalent. This design also allows them to be constructed in a variety of shapes and sizes, making them highly suitable for installation in cramped quarters.

However, while polyproylene soakwells are surprisingly strong, they cannot match the sheer load-bearing strength of concrete, and can be vulnerable to collapse when heavy vehicles (such as farm machinery and tractors) pass overhead. They can be reinforced relatively easily with internal plates, but be aware that these will add to the cost of installation, and may slightly reduce the soakwell's rate of drainage.