1. It is necessary to remember that we have to protect pipes against freezing if they have to be laid on external walls or in places subject to inflow of external air, and also under the floor in rooms where temperature can drop below 0⁰ C.

2. The size of covering on horizontal outflow pipes, made of PVC, has to be of at least 0.5m (it is not permitted to lay pipes directly under the floor on a hard concrete ground). In passages through construction obstacles (continuous footing, load bearing walls) protection sleeves are obligatory, a pipe junction cannot be placed inside a sleeve, and sleeves have to be filled with flexible stuffing.

3. Sewage pipes in the ground, under the floor, have to be laid on a sand bank, 15-20 cm thick. In I-IV class soils such bank is not necessary. The bottom of an excavation should be in virgin soil or protected against settlement of the sewage pipeline.

4. Sewage pipelines levels, which are touching directly living quarters, must have acoustic insulation. Heat and air insulation in furrows should be of at least 2 cm.

5. Furrows can be covered after partial acceptances. It is not allowed to fill furrows with building materials.

6. Both horizontal pipes, and the vertical ones, have to be fixed to the building’s structure with clamps or supports providing easy and durable assembly. Between the clamping ring and the pipe should be placed flexible washers. The clamping ring should fix the pipe under the flange.

7. Vertical sewage pipes, on every floor, should have at least one permanent fixing.