When the trap is too deep, liquid may flow through it too fast, which can lead to siphoning of the trap seal and sludge buildup. The drain connection at the wall is too high on this sink, resulting in a 9-inch-deep trap seal — 5 inches deeper than is allowed by code.
P traps that are either too deep or too long can collect too much water to the point that any debris that passes through the drain won't get washed away by the pressure of the water draining from the sink or tub. This will inevitably lead to more frequent clogs that are harder to remove.
Dimensions of a P-Trap
Another important dimension is the 'trap seal depth' - the height of the water seal inside the trap. This is typically between 2 and 4 inches, and is crucial in preventing sewer gases from entering the building.
Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm), or deeper for special designs ... The term "trap seal" shall mean the vertical distance between the crown weir and the dip of the trap ...
As we previously mentioned, it is a law in the United States that every shower has a P-trap. In addition to this rule, P-traps must be no more than 5 feet away from the shower drain. Ideally, it should be as close to your shower inlet as possible.
Each “P” trap shall have a water seal of not less than 2 inches and not more than 4 inches and shall be set true to its seal. (6) Size. Traps shall be not less than 1 1/4 inches in diameter. A trap shall not be larger than the waste pipe to which it is connected.
With most plumbing codes a minimum of 1 1/2" trap is required for a bathtub and 3 1/2' is the maximum distance allowed for a trap arm IF you go exactly at 1/4" per foot drop.
The depth of seal in the water trap needs to be a minimum of 75mm to comply with new build regulations where waste water discharges into a single stack waste system. Below are the common types of trap which are used on installations of sinks, basins and urinals.
The Uniform Plumbing Code states trap arms can for 1 1/2 pipe size = 30 inches, 2 inch can be 60 inches. Showers are 2 inch trap arm size.
Northern elephant seals can dive to depths of more than 5,000 feet and southern elephant seals to depths of nearly 7,000 feet.
Plumbing codes expressly prohibit the use of double traps. But what's the problem with this setup? I've been told that this will cause the sink to drain slower, increasing the potential for the trap to get clogged.
When pushing the cable through the P-trap, the U-shaped pipe section under the sink, you may encounter some friction and resistance. If this happens, push on the cable while cranking the drain snake slowly. A couple of turns will help the cable maneuver through the bends in the pipe.
If your sink is too deep, you might find yourself bending over too much, which can lead to back and shoulder pain.
Make sure the top of the P-trap and the bottom of the sink's tailpipe are properly aligned, then tighten the slip-joint nut by hand and then with slip-joint pliers until you feel moderate resistance. Repeat the process where the end of the P-trap meets the drainpipe that disappears into the wall or floor.
Is your P-trap working properly? If you detect any foul odors near the P-trap that remind you of a smell similar to rotten eggs, then it means that there is hydrogen sulfide present. This, and other harmful gases, bacteria, and viruses, can get into the house if your plumbing trap has malfunctioned.
When the trap is too deep, liquid may flow through it too fast, which can lead to siphoning of the trap seal and sludge buildup. The drain connection at the wall is too high on this sink, resulting in a 9-inch-deep trap seal — 5 inches deeper than is allowed by code.
How Long Does It Take for a P-Trap to Dry Out? P-traps can dry out as quickly as a month, sometimes even less than that. This happens most often in winter. To prevent your P-trap from drying out, run the sink or shower for a minute or two once a week to keep water flowing and your P-traps from drying out.
Unlike other plumbing fixes, there is no need to turn off the home's main water supply. You only need to make sure water going into the specific area you're working on is off. It's important to remember that this is still a wet process.
Foul Odours and Health Concerns
If a soil vent pipe becomes blocked or damaged, foul odours from trapped gases can infiltrate living spaces.
Can bath and shower waste join together? Yes, but care should be taken during installation. Since both appliances use the same size pipework (40mm waste pipe), having them connect to the same discharge pipe shouldn't be a problem.
The water pipe should be laid at depth of 750mm (minimum) to 1350mm (maximum).
Waterless traps
Wavin Osma's HepvO waterless trap provides a hygienic alternative to the traditional trap because it cannot dry out. Its self-sealing membrane provides permanent, watertight protection.
Section P-505 Bath Traps
The minimum size trap shall be 1-1/2 inches inside nominal diameter and shall have a water seal of not less than 2 inches and not more than 4 inches. Traps for bath tubs shall be made of cast brass, cast iron, DWV copper, galvanized durham piping, ABS, or PVC.
Running your sink obviously flushes water through the trap and down into the drain line. However, when you shut the faucet off, a small amount of water always remains inside the bend at the bottom of the P-trap. This water acts as a barrier that seals off the pipe so that the smelly sewer gases can't escape.