Modern Building Construction
Traditional construction has embraced gradual change over the last 50 years or so. A notable change has been the huge increase in in the use of plastics in almost all areas, from ground work to roofline from insulation to plumbing.
Once the groundwork foundations are dug, plastic drainage pipes are laid. These are normally, for house building purposes 110mm in diameter, and are made in 3 and 6 metre lengths.
A variety of bends, from 15% to 90% are available to allow flow flexibility. Junction pieces to conjoin pipes are made in T format or in Y format.
The manholes are pre-formed plastic bases with 3 or 5 pipe inlet holes and sit at the same level as the pipes. To get up to ground level collars called risers fit on the sides of the base and are available in depth sizes of from100mm to 500mm.
At ground level the chamber is covered by the manhole cover, again, in plastic, its strength and thickness chosen in regard of the anticipated weight of traffic. Obviously there are some areas which will only have pedestrian weights, and others with vehicular weights.
The groundworks required to install construction drainage commonly involves a backhoe loader.
Smaller traps or “bottle gullies” connect the drainage system to smaller inlets of water. The gullies hold water to stop foul air from escaping the foul main drainage system.
They are designed to accept waste water from kitchens, utility rooms and ground floor bathrooms, or rain water from paved areas or roofs.
Ideally the bottle gully could be connected to the manhole, but because it is roddable it may be positioned up to 20 metres away from one. This is providing the gully is less than 12 metres from the drain, and a set of drain rods must be able to pass right through the junction.
These are all made in compatible 110mm plastic, commonly with push fit connections.
Waste water and soil are carried to the underground system via 110mm waste pipes, the soil coming in directly in 110mm format, waste water through 32mm, 40mm or 50mm drainage pipes, all in plastic.
Once the roof trusses are in place the soffits and fascia are fixed on and the rain water drainage is attached, ie, the guttering and down pipes.
Almost all modern house construction will be using plastic UPVC guttering, with the most common 112/68mm half round. Larger gutter, for greater roof run off areas are usually deep flow, a similar profile but deeper, or an ogee formed system combining large flow volume with decorative frontage.
All are normally made in 4 metre lengths with push fit connections and bends to carry the gutter around the roof line.
The usual downpipes for the half round gutter are 68mm and are available in 2.5, 4 and 5.5 metre lengths, which bring the water down, usually into the underground drainage system.