• 1 Trap construction
  • 2 Material for trap manufacture
  • 3 Kinds of traps
    • 1 Corrugated trap
    • 2 Pipe traps
    • 3 Bottle traps
  • 4 Choosing the trap

There are many inconspicuous devices and appliances in our household that we rarely remember about. Trap in the bathroom is one of such things. Even expensive sanitary ware can’t do without it. The most popular products on the market are P-traps and bottle traps for the bathroom.

They are designed to drain wastewater to the sewage system and simultaneously to prevent ascending current of sewer gases from entering buildings.

Trap construction

A trap is a pipe or system of pipes with either a bend or a bottle. As in case of any other sanitary ware manufacturers constantly improve washbasin traps.


Construction of a trap

However, assembly parts of the trap are sold in standard kits:

  1. Drain cover or filter mesh with five-six slots of diameter not exceeding ten millimetres.
  2. Thick rubber washers of three to five millimetres of thickness. Please, mind that washers are, as a rule, of black colour. In models that are more expensive, they are white.
  3. Discharge or outlet pipe with small rim for fitting the washer and two-three compression seal rings.

Please, mind that depending on the model outlet pipe may be furnished with one more inlet for such appliances as a dishwasher or washing machine.

  1. Coupling screw with diameter not exceeding eight millimetres.


It is better to choose the model with stainless steel coupling screw.

  1. Trap body.
  2. Nuts.
  3. Sewer connection.


Material for trap manufacture

Material for manufacturing traps should be thermally and chemically stable. Usually washbasin traps are produced from plastic, cast-iron, nickel, brass or brass and bronze alloys.


Traps may be manufactured from different materials

Taking into account exploitation experience, the most practical in use are plastic traps. They do not rust or rot.

Copper-alloys of brass and bronze, which are usually coated with chrome, are also durable. Such traps are not apt to corrosion.

However, in time they get covered with oxide film. These uneven surfaces start catching dirt, which grows more and more with the time. Plastic traps in this respect are much more practical.

Plastic trap has one undeniable advantage over metal ones. Plastic shows bigger expansion coefficient, which simplifies mounting process to a great extent.

While mounting plastic traps you need no additional materials for sealing as they are replaced by pipe coupling.


Kinds of traps

Nowadays there are many varieties of traps.

The main types are as follows:

  • Bath traps, consisting of two pipes – drainpipe and overflow. They are joined before the water seal. Further water flows into sewer through a single pipe.


Bath trap should not be a single-piece.

Its pipes should be easily regulated in length and fit into any waste outlet.

  • Shower cabin traps are installed into shower tray or directly into the floor.
  • Washing machine traps. This trap is placed in the box, which then is fixed to the wall (either behind washing machine or at its side).
  • Kitchen traps. Most often for the kitchen customers choose a trap with an overflow for the sink and several outlets to connect a dishwasher. This trap is installed underneath the sink.
  • Washbasin traps (corrugated, pipe and bottle ones).

While fitting sanitary ware, use a trap of appropriate type. Installation of inappropriate trap may result in breaks and leaks.

Corrugated traps

Construction of corrugated trap is the simplest one. To make a water seal one of its part is a bend fixed with plastic band. Its other part remains flexible and bends well.


Corrugated trap

Corrugated traps for bath and washbasins are easy to install. Flexible frame allows installation at any place. However, its folds soon clog with grease, dirt, soapy wastes resulting in bath clogging. You may remove it with household chemicals or by dismounting the trap.

Pipe traps

Undeniable advantage of pipe traps is their small size that it why they ideally fit in small bathrooms.

As a rule, pipe traps are made S-shaped or U-shaped. This is a bent plastic or metal pipe furnished with a cleanout. Installation of the given type is possible only if space under the washbasins is big enough and allows it.


S-bend and U-bend traps

Bottle traps

Visually bottle trap is known to nearly everybody. This type’s design reminds a bottle and has a rigid construction. It is very convenient for cleaning all sorts of blockages, as its bottom can be unscrewed.

Bottle trap prevents the smells of sewage due to some water remaining in the trap.


Bottle traps may be manufactured from different materials

Often bottle traps are furnished with overflows, which serve for water control in the washbasin. The overflow does not let water flow over the rims of the basin.


Choosing the trap

While choosing the trap you should first pay attention to category of the sanitary ware. If you have standard parameters and characteristics of the washbasin, it is easy to find the trap matching them. For standard waste outlet standard trap will do nicely.


While choosing the trap keep in mind the model of your washbasin


If bathroom washbasin was manufactured on your individual order, you should buy the trap together with the ready product even if it will cost you more than standard ones.

While making your choice, take into account water volume that is going to flow through the trap daily.

Trap design is just as important as its performance characteristics. Traps may be narrow, wide, with attached cap or in-built plug.

When buying the product, pay attention to quality characteristic of washers and seals as it will help you to avoid troubles while using it.