View Full Version : toilet science

10-15-2012, 10:42 AM
Hello, this is my first post at this forum.

I have a question to you about toilets science. How do they function and what is the best design ever made? I spoke to the guy in Home Depot and he told me that all toilets pretty much the same. But I think that there is must be a best of the best proven by time and patented design.

First of all my basement toilet works not as good as the one on the second floor. It flashes not as quickly, basically waters goes in it and circles "marry go round". Sometimes I have to use plunger, but not too frequently...may be once in 6 month or so. This toilet is very old probably 30 years old. I did scarp it already as I do my bathroom renovation.

I spoke to a plumber from the shop and he told me that the difference between these two toilets is the height- one in the basement has a very small pipe slope. Also he pointed that it might be a problem with the vent pipe- basement toilet is located too far from it.

Currently I am doing my washroom renovation in my basement and I am just wondering if this pressure assist toilet would improve my situation with basement toilet?

Another potion I am thinking just purchasing this Toto Drake II toilet. As I have heard it is the best of the best...

Also I refer to some info posted here:

If the flange is setting above the floor, one will do.
If the flange is setting on the lower plywood, not on the underlayment, then two wax rings.

If my flange is setting on the lower plywood, not on the underlayment, may be I need to use the flange extender and bring it up to the level of the above tiles instead of using double wax rings?

Thank you!

10-15-2012, 12:40 PM
Your old toilet was probably calcified which had nothing to do with the piping. A toilet will flush, and maybe flush better, without a vent. A power flush pushed the material out of the toilet "faster", but once the material is in the pipes it doesn't make any difference what kind of toilet you had. The Toto may be the "best of the best", but I have only installed about 8 of them in all the years I have been installing toilets. I have not had any customers complain about the function of the ones I do use, either.

10-15-2012, 12:49 PM
The Drake II is a great toilet. All toilets are not designed the same.

There are pressure toilets and gravity toilets and the designs of the bowl are very different. On this forum, we find gravity toilets (where gravity pulls the water from the tank) to be much quieter, and safe and reliable, provided they are designed well. Many are not. Virtually all Toto toilets are well-designed. The Drake II that you are considering provides excellent bowl wash, excellent disposal of the waste, and does so with very little water usage. It is a comfortable height, and has a special coating to reduce water marks and other nasty marks inside the bowl. It is solidly-built. Toto has demonstrated over and over a commitment to quality and is well-known among professionals for not selling toilets with defects (as compared to what happens too often with some of the brands sold at Home Depot). You can easily find replacement parts for it when the time comes to change the flapper or fill valve (the major working parts).

From your description, two wax rings should be fine. Get one with a horn in it and one without. Put the one without the horn on the bottom and the one with the horn on the top. You may also be able simply to use an extra-thick wax ring, which can be double the size of the regular wax ring. If you do this right, you should have a better seal than if you used a flange-extender.

Good luck and let us know how it goes.

10-15-2012, 12:51 PM
Here's a comment from someone replacing a Glacier Bay from Home Depot with a TOTO Vespin/Drake Dual Cyclone.

We have successfully installed the Toto Vespin II today and it is truly a one flush wonder. I have Crohn's disease and this is the first residential toilet to work with only one flush. FIRST! That dual cyclone flush is amazing.

A Flushmate pressure assist is pretty much unpluggable, not a guaranteed bowl rinse though.

If you have something in the trapway, of it has calcified, then you can get the slow flush. Normally, once it drops or siphons out of the bowl, it's gone.

Flange on top of the floor, one wax ring
Flange below, as in the flooring has been cut around the flange, then two wax rings.

Gary Swart
10-15-2012, 01:03 PM
Smock man at HD gave you their pat party line when he said all toilets are pretty much the same. This may have been more or less accurate in pre low flow days when all toilets used a large volume of water, but when low flow became the law of the land (USA) things changed. Most of the old, well known brands tried to meet the new standards by tweaking their existing flush mechanisms. The results were awful and made low flow toilets unpopular. At least one company, Toto, realized that there needed to be a redesign of the trap way inside the toilet, and using modern technology did this and proved that it was possible to have a high performance toilet that used half the volume of water. They did have a couple of early models that did not perform well, but they were soon replaced by the Toto Drake and other models that would meet the standard of low flow and still provide a good flush. Meanwhile other companies continued to redesign the redesigned mechanics with little success. The result of all of this made Toto the largest manufacturer of toilets in the entire world. They didn't stop with just meeting the 1.6 gpf standard, they further refined their designs making a 1.28 gpf possible, and now, they have a 1 gpf that should be marketed soon. Since the average layman does not really research all of this, the Big Box Stores continue to sell their $99 toilet-in-a-box to the public who think having to flush twice is normal for low flow toilets and to builders of spec houses who couldn't care less if the thrones they install will perform well or not as long as they are cheap. In addition, many of the well known brands have been merged and no longer produce the quality products they did in days of yore. You won't find a Toto in a discount store, but any plumbing shop can get them even if they don't stock them.

10-15-2012, 01:10 PM
Thank you all for your prompt replies!

My basement floor was too high due to the sub floor thickness, people who were installing the new bath tab, they reduced the sub floor thickness by half and they did cut an old flange, as it was too high. Unfortunately my old flange was glued on the outer surface of the pipe and the new flange they installed went inside the pipe. Now I have smaller diameter of the pipe due to the new flange. Should't it be a problem in my case, reduced flow or so? I assume it is not as this new flange was purchased in Home Depot, it means it is standard flange.

10-15-2012, 01:12 PM
Most trapways are around 2"

The pipe in the ground should be 3" or 4"
That's not going to be a problem.

10-15-2012, 01:37 PM
Thank you again Terry!

Last question I have is about rough in distance. Tiles in my bathroom not installed yet, because I moved from the original tile to slightly thicker natural stone, I assume that my real rough in distance might be slightly less then 12 inches. How much play regular toilet would have in this regard? Should 11-3/4 inches be sufficient enough or I should talk to my tile guy to reduce the thickness of the mortar to be exactly @ 12 inches? What is my "alarm level" here?

10-15-2012, 01:51 PM
You're saying 12" from the finished wall to the center of the closet flange, right?

There are some toilets that require the entire 12". There are some that require less.

At 11.75", you will probably be okay with the Toto Drake (which can usually fit on about 11") and the Toto Drake II (which can usually fit on 11.5"). Terry pointed out recently that how perfectly-vertical the wall is can make a difference, as can variances from toilet to toilet, when you are right at the margin. However, 11.75 should be okay with either of these toilets.

10-15-2012, 08:35 PM

You asked:
How do they function...

Welcome to Toiletology 101:

A toilet bowl works on exactly the same principle as a siphon hose. With a siphon hose, you suck on the end of the hose to fill it with liquid, and once filled, the liquid will keep flowing through that hose as long as the hose will take it to a lower elevation.

Inside the toilet bowl will be a "weir" which holds a certain amount of water in the bowl. When the tank releases it's water into the bowl, the water overflowing that weir is sufficient to flood the channel behind the weir (which people in here are calling a "trap way") with water. That's why that "trap way" isn't made nice and straight, but curving so that it slows down the speed at which water flows through it. The slower water can flow through that trapway, the greater the liklihood that the water overflowing the weir will completely fill that trapway with water.

And, once that trap way is full of water, the same laws of physics take over, and that trap way suddenly becomes a 2 1/2 inch diameter siphon hose that's sucking the water out of the toilet bowl.

So, a toilet bowl trap way and a siphon hose are right beside each other on the physics tree, they just get filled with liquid differently. But, once filled, they work exactly the same.

You can use that understanding to help diagnose toilet problems. If you have a toilet with a weak flush, pour a 5 gallon pail of water into the bowl as fast as you can without spilling water all over your floor. If you then get a powerful flush, there's nothing wrong with the bowl; the problem is that there's not enough water overflowing the weir fast enough to completely fill the trap way, and that's the key to getting a great flush. Check your toilet tank water level is where it should be, check the flapper in the tank is opening fully, and check that the holes under the bowl rim and the jet hole at the bottom of the bowl are all open and flowing.

If the toilet flush is still weak, then the problem is in the bowl or downstream of it. There might be something caught in the trap way, or in the drain pipe from the toilet. Perhaps the drain piping in the house is partially clogged and the water is backing up so there simply isn't room for the addition water in the drain piping.

10-16-2012, 12:31 PM
Thank you for your reply nestork.

When I was a kid I had a toilet like this.

The water tank was located 2 meters above the ground plus inside it had a very unique design. It had some kind of pedestal
so the solid waste was always going into it, so it has very quick flash as this "waste" was removed right after water streamed into it.

Nowadays they changed the design, so "waste" goes directly into "small water pool" in it, so when flash starts water would flow, but not the "waste" in it....

This so called "waste" has different density from water, so it would not follow the water path so quickly...