Project – Wide Lane, Southampton

Client – Winvic construction

Cost – £70,000

Substructure size – 5no. Varying

Time on site – 10days

If you need to construct a substructure for your project, we understand that you’re going to want it not to leak, crack or be built to very low tolerances (all issues that are common with in situ concrete).

Below, we’re going to highlight one project where we helped a client overcome these challenges with a prefabricated steel substructure, and the difference it made to their project.

The challenge

We were contacted by one of our repeat clients, Winvic Construction, who needed to install below-ground substructures for an industrial laundrette.

They required:

• 3no. 1m (w) x 4m (l) x 2.5m (d) to used to store machinery
• 1no. 2m (w) x 4m (l) x 4m (d) to be used as an interceptor tank
• 1no. 1.5m (w) x 1.5m (l) x 1.5m (d) to be used as storage

In this case, the main objective and concern for the client was to find a way to de-risk the construction process, as a traditional in situ concrete approach could lead to cracks and leaks. Not to mention the substructures themselves could end up being built to low tolerances.

One of the required substructures was 4m deep, meaning it would have required a hole that was 8m x 8m wide – there simply wasn’t enough room on-site.

Time for another significant driver, as with a traditional method like in situ, it would have taken around five weeks to build – and around nine weeks in total to complete this part of the project.

Three of the other substructures required a detailed shelf at the top, which would prove very tricky to build with precast or in situ concrete – therefore, our method was far more suited to the project, and this particular shape of substructure.

The design we received from Winvic was for traditional in situ concrete substructures, as many projects are originally designed with this in mind, before clients realise there may be a better alternative – with less likelihood of defects occurring.

As this building was to be used for a laundrette, we knew that the challenge would really be pricing the works with the right materials, so there would be no issues with anyone thinking there was a possibility of the substructures rusting.

The solution

Having worked with us before, and being fully aware of our unique and innovative method of below-ground construction, Winvic were delighted when we quoted them 10 days for the installation.

Our fully costed project included us completing the design, delivery, installation and all materials, including excavating and pouring concrete. Winvic compared the cost of them excavating the earth and supplying the concrete – which we would then pour as part of the installation process, but it was more economical a more risk averse approach for us to do this.

This meant we were able to work within their budget, and they were pleased to use us as a “one-stop shop” to complete all the works.

We sat down with our client and discussed how the other substructures were to be used, before agreeing that the most cost-effective material was mild steel.

This was ideal as the substructures would not come into contact with water, and would last over 120 years.

We constructed the large interceptor tank with 304-grade stainless steel, which would not be affected by the chemicals in the water.

We also fitted connections onto the tank so that they were the correct diameter for the on-site pipes and fitted at the exact invert level.

The results

Winvic were very pleased with the end-result, which led to a faster installation time and resulted in substructures that were bespoke and perfectly suited to the industrial laundrette’s needs – with no chance of rusting.

Essentially, our method of prefabricated steel de-risked their programme, and allowed them to complete their project on time, and without any defects.