More Plumbing For Kids - The Kitchen Sink

In a recent post, kids learned about how a toilet works. We will build on that knowledge and
include what we have already learned about plumbing for kids.

In the post about how a toilet works, we learned about a trap and how it stays full of water. Now
we will take that knowledge and learn about the kitchen sink. The homeowner/parent will open
the doors below the sink and clear out buckets, and all manner of cleansers so the children can
get a look at how the sink works.

Garbage Disposal

First, let’s look at the garbage disposal. When we talked about how a toilet works, we used a
big word “biodegradable.” That word is useful for the garbage disposal as well. The only things
that should be put into a garbage disposal are food items that will eventually be broken down by
water and microorganisms. This means no bones, no plastic items, no cardboard, no metal.

Disposal Do’s And Don’ts

Children should understand that they are NEVER, NEVER, NEVER  to put their hand inside the garbage disposal. The disposal will grind up fingers just as easily as it does meat and mashed potatoes. If the disposal is jammed, an adult will turn off the power to the disposal and remove the bits of glass, bone or metal (a small fork perhaps?) that have blocked the disposal’s operation. Once the offending piece has been removed, the disposal can be safely started again.

The child should be told that if he is unsure about placing an object in the disposal, the item in
question should be thrown away in the garbage instead.

The adult can run the disposal and point out below the sink how ground-up remains from the
disposal can now flow downward in a pipe that joins a descending pipe from the sink at a joint.
From there, the water and material will flow through a trap and out a wastewater pipe into the

Children will probably have a few questions, including “What keeps the water from the disposal
from coming back into the sink?” and “The trap really doesn’t seem to do anything, does it?”

The adult can answer the first of these excellent questions by shining a flashlight down the sink.
Often the child will see a small flange in the pipe that will direct the waste from the disposal
downward, rather than allow it to spurt upward into the sink. It is important for the kids to see
how the sink and the disposal are connected; that water from both the sink and the disposal flow
downward into the same pipe.

The Trap Stops Smells

In the next step in explaining plumbing for kids, the adult will need to fill a pitcher with water for a simple demonstration of how the trap works. Ask the child if smells can travel through metal.
They might have to think for a moment before answering, “No.” “Can smells travel through wood?” Now the answer comes quicker: “No.” Can smells travel through air? In other words, if
someone is cooking a hamburger and French fries in the kitchen, can you smell it in your room?
The answer, of course, is “Yes.” Can smells travel through water? By now they have figured it
out. The answer is “No.”

Now show the kids the under-the- sink hardware again. Have them trace with their hand the flow
of water from the sink through the trap to the wastewater pipe. Now they can visualize how the
trap can block smells coming from the sewer into the house.

Redirect their attention back to the water pitcher half full of water in the sink. Have the children
put some small bits of food left over from their last meal into the bottom of the pitcher. Now have
the children run water from the faucet into the pitcher. They can see it overflowing, flushing out
the food bits and filling with more water.

“Do you see how the trap works?” says the in-home plumbing expert. “The food and junk are
flushed out and more water replaces it, so the smells stay out.”

Here’s a tough question in plumbing for kids. Ask the children, “What would happen if they left
home for a long time, months perhaps. Would the water always be in the trap?”

Here’s a secondary question for them. “If you left water out in a bowl would it still be there after
a month?” The answer is, “Probably not.”

Evaporation would eliminate much of the water. The same is true in a sink that has not been used for several months. The water in the trap could evaporate. Without that barrier in place, sewer gases could creep into the house bringing its nauseating smells inside. Not good!

To summarize our plumbing for kids ”tour,” they now know about traps, sewer gas and what to
do and NOT to do with a garbage disposal. You are preparing the next generation of homeowners.