A Floor Drain is a plumbing fixture that is usually installed by a plumber as a means of draining water from a floor area after a spill.
And it can be 2 and 3-inches in sizes.
(although it is possible to find a 4-inch floor drain)
A general rule of thumb is that if the floor drain (FD) is in contact with the ground, such as in a basement floor, then the size is 3-inch.
If the floor drain is serving an upper floor area, such as a main floor laundry room, then the size is 2-inch.
According to the Ontario Plumbing Code, all basements of a dwelling unit must have an FD.
Including homes and apartments.
The following locations of other buildings must have at least one floor drain:
Garbage room, Public laundry room, incinerator room,
heating or boiler room in a building with more than one dwelling unit. And anywhere that there is a high likelihood of a large water spill.
If the water in FD cannot flow naturally by gravity into the building drain ( It is below the building drain) then the plumber may connect the floor drain to the storm pipe, drainage ditch, or dry well and it can take only clear water waste.
A Floor drain cannot be attached to the drainage system if it is in the following locations:
In a room with flammable or dangerous chemicals, a high voltage room, or and oil transformer vault,
this is to prevent movement of a possible hazard in the event of a spill. If a Floor Drain is in an elevator pit, then it must meet the requirements of the Safety Code for Elevators.
All Floor Drains must have a Trap.
However, if there is more than one FD in a room and if those
Floor Drains do not contain food or organic waste then the plumber can install one trap for more than one FD.
This type of installation is known as gang trapping.
A Vent is a must for All Floor Drain Traps.
There is no need to use separate vent for a floor drain if it fits the following rules:
1) The size of the FD is at least 3inch.
2) The fixture drain or the length is minimum of 450mm
The slope or fall for a fixture drain is not greater than it’s inside diameter
( 3-inch or less fall on a 3-inch drain pipe).
3) The minimum slope of the 3-inch drain is 1 in 50 ( or 1 in 100 if the floor drain is more than 3-inch)
Floor drains often lose their trap seals from evaporation because often they are not in use for some periods of time.
To prevent this and the result, which is sewer gas entering the building, a provision for maintaining the seal must take place on all floor drains, adding water to the trap.
Adding water is done by several means.
The preferable ways are:
using the flush valve of a water closet, indirectly connecting the floor drain to a drinking fountain, or installing a trap seal primer.
The tube to connect the floor drain to its supply of water must be at least 3/8 inches in size.