How to install plumbing on a concrete slab
Construction and plumbing of a house requires skill, perseverance, precision and aptitude. The systems of pipes in concrete slabs go in before pouring the concrete, since they are installed under the slab. But before you can pour the slab, the construction inspector must first approve and sign the waste and respiration drain, or S and V, of the system.
The plumbing ditches
The drawings of the foundation for its detail of the house where a backhoe should dig the trenches for the DWV system. While you can install water supply lines on the same walls – these supply pipe fittings from behind the walls – you must dig ditches that are placed under the slab to install the DWV system that drains into the sewer connection final. Each ditch must have a slope that matches local building codes, typically a 1/4 inch drop per foot. You may need a pump station if the house is below the sewer connection.
Foot or heel-outs tubes
The plumbing trenches are typically excavated at the same time as the slab shoes, if any. Once the trenches are dug, you can add sewer pipes and stub-outs – pipes that are placed above the floor plate so that you eventually connect the sink, toilet, tub or shower, and no other drains to the system. It is also necessary to wait for ventilation piles that should eventually go all the way through the roof. Plumbing code dictates how many accessories can attach to each vent and drain pipe.
Traps, vents and cleaning facility
Plumbing code requires that each plumbing fixture has a trap and a vent pipe that it grants. The codes also require cleanings installed outside the slab, usually near the outside of the base at its top end. Properly installed cleanings make it easy to maintain the system, especially if it is a backup. Vacuum cleaning includes a pipe that is above grade, with a sewer cover that tightens.
The size of the drains, heel-outs and vent chimneys are based on the accessories that will be attached to them or where they are placed according to tables of plumbing codes. The final size of drain pipe is determined by the number of bathrooms and accessories in a home. Each bathroom, sink and drain in the house must have a waiting piece in the S and V system that is above the final height of the slab.
System checks and tests
The building inspector usually requires a temporary pipe – at least 10 feet tall – top of the last accessory added to the S and V system to prove that there is no air or water leakage. If it is filtered, the system must be repaired before pouring the slab. The sewer line to the septic or sewer system must also be tested in the same way.