Can A P Trap Be Too Low (Explained)

The P Trap plays an important role in our drainage system as such the way they are positioned is crucial, when positioned well, it allows it to play it roles on preventing gas from entering our homes ;

Back to the questions how Far Does a P-Trap Have to Be Below a Sink?
Understanding the minimum and maximum length between the P Trap and the sink drain will save us from lots of trouble.

Although there is no building code that specifically spelt out the recommended minimum length between the P Trap and the sink drain but their distance is determined largely by several factors that comes into play during the installation.Can A P Trap Be Too Low

Lets not forget to tell you that there is a recommended maximum length from the International Residential Code which states that the maximum vertical distance or length from your sink drain and the entrance to the p-trap should be 24 inches.

The P Trap shouldn’t be above 24 inches because if it exceed, there will be too much velocity that is capable of taking all water away from the P Trap and this will lead to harmful gas coming into your home rendering the P Trap totally useless.

To pass inspection you need to install your P Trap just below your sink, this normally gives you an easy flow of water out from your kitchen sink.

A P Trap shouldn’t be too low, it should just be install 6 – 8 inches in length when it comes to how short it could be.

when a P Trap is too low then there will be problems of free flow of water as the water won’t get enough momentum to push debris away from the P Trap.

on the other hand If your p trap is too high (more than 24 inches) you wont get good drainage either as their will be too much velocity that will empty the P Trap rendering it useless and also you wont be able to hookup your garbage disposal.


Can P-trap Be Higher Than waste Pipe?

No, its not recommended that a P-trap be higher than waste pipe rather It should be below or lower than the waste pipe to allow easy and natural flow of water or waste.

Also ensure that there is a vent which should prevent water from the P Trap from drying up or being sucked out thereby allowing gas and other smell entering into your home.

Hence the maximum length of a P Trap from the waste pipe as recommended from Universal Plumbing Code stipulates 24 inches, in most cases this could be less but it should not exceed this.

How Do I Tell If My P trap Is Too High

Your P Trap is too high if its higher than the maximum recommended hight as stipulated by the Universal Plumbing Code.

According to the Universal Plumbing Code you should not exceed 24 inches.

Remember we said that if your P Trap is too high then the water is bound to develop massive momentum that will empty your P Trap.

Does The Height Of The P trap Matter?

Yes the height of a p trap matters a lot, lets assume that your p trap is very short and its just above the waste pipe then there will be trouble.

First you wont be able to install your garbage disposal and secondly the garbage disposal is likely to get filled up with water all the time leaving you with a poor drainage flow.

What Is The Standard Hight For P Trap

That standard hight for a p trap to ensure free flow of water or waste should be, 6 – 8 inches long. There are some cases where i personally have seen where it was 12

If its for washing machine then you ensure that you meet the standard rules which means that you should just install the trap on the drainpipe keeping hight between 6 and 18 inches from the floor.

So basically in the industry its generally known that 18 inches is the hight to keep in mind for washing machine.

Lastly it will not be a bad idea if you consult with professional like building inspector in your locality to be sure that what you come up with is up to the required code to avoid violation.

Does A Drain Need A P trap

Installing P Trap to every drain is necessary because they play one important function which is to prevent smell and gas from rising out and spreading into your home.

So a drain need a p trap to prevent exposure to gases which pose serious health problems to human most importantly in a poorly ventilated space.

Does P-trap Have To Be Directly Below Shower Drain ?

In the State, the recommended vertical maximum length of the p trap is 24 inches as such it should be just under the shower drain.

Having a p trap underneath the shower drain will help the water or waste to develop a lot of velocity that is required and needed to push any dirt away from the p trap.

The more vertical your p trap is positioned then the better for it to work, swiftly pushing dirt away.

But Due to the fact that traps and Shower drains are known for getting hair clogs most people wont recommend to have a P trap directly below shower drain.

Which ever way you chose Just ensure that the P-trap is close to your shower drain as close as possible and also be position in a place where it should be self cleansing so you will have no issues.


The role of p trap can’t be overemphasized hence it is necessary we have them installed in our drain to prevent maliferous scent from entering into our home thereby endangering our lives.

The position and length of a p trap is important to enable it to be self cleansing.

We should also know that the maximum length of a p trap shouldn’t be more than 24 inches while there is no specific minimum length.

Leave a Comment