
Public sewer excavation can be a surprisingly complex business. Not only must we take account of other services which might run close to the sewer lines (for example, water mains or telecommunications cables), but in urban areas there are all sorts of obstacles we might have to work around, from roads and buildings to subterranean structures.
There are several different sewer excavation methods we use depending on the site and situation – we might even use a particular way of working for budgetary reasons, to help our customers keep a handle on costs. Here’s a quick guide to the different sewer excavation methods we use on site, and why:
Open cut
The open cut method is the simplest type of sewer excavation to explain – it’s a case of digging a trench in the road or footpath to reveal the public sewer, before working within the trench to install the new sewer connection. We use a hydraulic aluminium waler system with trench sheeting, to brace against the sides of the trench and keep our workers safe within the confined space. Its exact specification depends on depth and ground conditions.
Open cut can be the least costly way of accessing a public sewer in areas where there is plenty of room for machinery, and road closures won’t impact too heavily on the daily life of residents and businesses in the area.
Dig and push
Where public sewer excavation is required on a line which is set deep, especially in a confined footprint, the dig and push method is a go-to option. Trench boxes, made from steel or aluminium, enable the sides to be cut vertically, and are pushed into the ground as an excavator removes soil from between the panels.
Timber headings
A time-honoured method of sewer excavation – which has been used for centuries – timber headings are ideal for making sewer connections in urban areas, because they enable minimal disruption at ground level. It’s also the perfect sewer excavation method for working in places where it’s not possible to get heavy machinery on site, where there are buildings in the way, where it’s unclear where other services are located, or where it’s critical to keep disruption to a minimum. For example, we use timber headings when we work in central London, to help control costs that might otherwise be incurred through lane closures and the TFL rental scheme.
For advice on which sewer excavation method will be most appropriate for your sewer connection works, call 01268 950050 or send us an email to [email protected].