Cotterill Civils provide a range of concrete manhole rings in a range of diameters and depths. Each of them comes in the form of precast concrete rings, and all of them have a tongue and groove joint to allow them to lock together neatly and easily. Once put together, they can be sealed with cement and sand mortar or a bitumen sealant, making them watertight and helping to prolong their lifespan. Able to withstand infiltration and attack by groundwater and corrosive environments, these precast concrete manholes will remain in pristine condition for many years.
With incredibly long lifespans, these sturdy and reliable concrete rings also include ladder rungs for easier access to the lower levels, and can be stacked indefinitely to reach whatever level you need, with far faster construction time than casting the rings onsite would allow for.
Precast concrete rings allow for a quick, easy installation and can be easily sealed against the elements, and precast concrete cover slabs are also available which can be used to cap the manhole chamber and reduce the size of its entry point. Commonly used in deeper manholes, these concrete manhole covers or “landing slabs” are installed at intervals through the tunnel, preventing a long fall or allowing regular resting points along the length of the concrete manhole.