BLOWING UP & BURPING TOILETS: CAUSES & PREVENTION
Author: Ed Fitzgerald
First it’s good to know that although the words, “blowing up” are used, nothing really explodes. WHEW!
Truth is it all comes down to airflow venting and airflow restriction.
So let’s start with venting…
Through the early 1980s, four inch vent stacks ran out of many homes, and within three feet of that stack are the toilet, the sink, the bathtub, and they’re all tied into it.
Then in the early to mid 80s the size of the vent stack was reduced from four to three inches. No problem!
In the late 90s the vent stack got smaller again, by an inch, becoming a two inch vent stack to accommodate the prefab homes built in in the South and then moved where plumbing codes were different. And eventually the two inch vent stack got to be accepted nationwide. If you think about it, the eight inch sewer line is reduced once it goes to the lateral, typically a six inch, and again when it gets to the house it’s reduced to four inches. Once it turns up on the floor and goes up, it’s now three inch and you’ve got all this air generated by the tool is traveling up that line. And when you start reducing the size of the pipe, you can increase the velocity or the speed of the air. If the houses are not vented correctly, or the vent is clogged, your chances of pushing the air through the toilet, and pushing all the material out.
The other piece of the puzzle: restricting airflow. Are you pulling too much material behind that nozzle and there’s nowhere for that airflow to go but up that lateral or do you have a belly in the pipe that’s causing that airflow to be restricted. This is where step cleaning comes in and knowing what you’re cleaning and the proper tools to use.
So we know the two main reasons for blowing the commode: airflow venting and airflow restrictions
How can we prevent blowing up toilets?
The first step is reducing airflow. The key is using the right nozzle with the right spray angle. Nozzles with “straight back” jets do a great job of moving material but increase the amount of airflow in the pipe. Utilizing a spinning or a nozzle manufactured to reduce airflow, (generally at 60 GPM for 8” & 10” pipe). These nozzles have a higher degree of spray angle, combined with a slow rotating head, which in turn reduces the airflow in the pipe.