Fixing a Toilet on a Concrete Floor: A Comprehensive Guide

When it comes to installing a toilet on a concrete floor, the process can be slightly different compared to installing one on a wooden floor. This guide will walk you through the essential steps to ensure a firm and secure installation.

Steps to Fix a Toilet on a Concrete Floor

To properly attach a toilet to a concrete floor, follow these steps:

Remove the Old Wax Ring: Start by removing the old wax ring. This is crucial for creating a new, airtight seal for the toilet. Clean the Area: Thoroughly clean the floor area around where the toilet will be installed. Any debris or old wax ring remnants will affect the installation and seal. Install a New Wax Ring: Carefully place a new wax ring over the drain. Ensure it’s centered and properly positioned. Align and Lower the Toilet: Align the toilet with the flange and slowly lower it into place. It’s important to ensure the toilet is level and correctly aligned before securing it further. Secure with Nuts on Bolts: Use washers and nuts to secure the toilet to the flange. Tighten the bolts firmly but avoid overtightening to avoid damaging the wax ring. Reconnect the Water Supply: Attach the water supply line to the fill valve and ensure it’s connected tightly to prevent leaks. Test for Leaks: Turn on the water and check for any leaks around the bowl and at the water supply lines.

A Special Case: No Existing Toilet and Unknown Floor Height

Recently, I faced a challenge where there was no existing toilet, and the floor height was uncertain. Here’s how I approached the situation:

Preparation: Before the masonry and tiling work, I ran plumbing in the floor. I did not finish the floor myself, so I left the hub of the elbow below the floor level. I created a form around the elbow using a coffee can with the bottom removed. The mason poured the concrete floor, and the tiler added the mud set and tiles.

Adjusting the Flange Height: After the tiling was complete, I removed the form (coffee can) and added the pipe and flange to achieve the desired height. However, my mistake was not making the form larger than the flange, making it hard to pour concrete around it securely. To solve this, I used hydraulic cement, which is fluid when mixed. I constructed a makeshift funnel and poured it through the holes that the bolts typically secure the toilet to, tapping it with a hammer to encourage settling. The height of the cement was adjusted to just below the bottom of the flange.

Securing the Flange: In a scenario where there isn’t much room to encase the pipe and flange, I would have used bolts or screws into the wet concrete. However, in my case, the concrete was solid, and I decided not to use these methods. The idea was to prevent the toilet from shifting or rocking, which can compromise the seal and cause leaks.

Advanced Techniques for Firm Base

Adding a layer of plaster under the bowl is a common practice that can provide a firmer base and prevent shifting or rocking. Plaster of Paris or any similar plaster can be mixed and used to create this bed before installing the toilet. This technique ensures the toilet is firmly secured and reduces the risk of leaks.

Conclusion

Properly installing a toilet on a concrete floor requires careful preparation and adherence to the correct techniques. By following the steps outlined here and using appropriate materials, you can ensure a secure and leak-free installation.