It is clearly important to be able to gain access to all parts of the underground drains. This is usually done by providing inspection chambers at various points. To meet the Building Regulations, chambers have to be provided: at junctions between drains; where the drain changes direction or gradient; at or near the beginning of the drain; and at intervals of not more than 45m on long, straight runs. In between the inspection chambers, the drains should be laid in straight lines. It’s always wise to call for drain cleaning in Bergen County if you own a septic tank to help avoid potential sewage disasters.
The usual form of an inspection chamber has sides made of brick, often cement-rendered either on the inside or the outside. At the base of the hole are open channels to which the drains are connected and along which the water in the drains runs. The inspection chamber is at a junction between three drains. The branch drain is connected to the main one with a specially shaped half-channel bend which is swept in the direction of the flow of water through the main channel. The channels are built up with benching – smoothly finished concrete shaped to direct any splashes back into the channels. The top of an inspection chamber is covered with a manhole cover a heavy, cast-iron plate set in a cast-iron frame. If there is a manhole cover within a building it usually has to be screwed down to the frame and the joint sealed with grease.
In older properties, the inspection chamber at the boundary of the property may have an interceptor trap fitted at the outlet of the channel. To gain access to the length of drain between the trap and the main sewer, the trap has its own rodding arm which bypasses the U-bend. The rodding arm is fitted with a stopper (sometimes secured with a chain) to prevent the drain water from bypassing the U-bend, too.