How to Install a New Subfloor Around a Toilet Flange

  • 4-8 hours
  • Intermediate
  • 125-500
What You'll Need
Tape measure
Saw
Plywood
Replacement tile
Tile nippers
Grout
Trowel
2x4s
Screw gun
Wood screws
What You'll Need
Tape measure
Saw
Plywood
Replacement tile
Tile nippers
Grout
Trowel
2x4s
Screw gun
Wood screws

Toilet flange is a pipe fitting that basically has two functions. The first is that it connects the floor drain to the drain of your toilet. The second is that it holds the toilet to the floor securely. Sometimes, the subfloor around your toilet will become soft and may begin to rot. This could be because of leaks or overflows. Whatever the problem may be, it is important that you replace the floor as soon as you notice any type of weakness in it as it could result in much bigger problems later on.

Step 1 – Measure

Like with most projects, you will have to start out with some good measurements. It is always in your best interest to measure the area more than once. The more accurate the measurements, the better off you will be. Once you have your measurements, you will need to remember them so that you can take them to the store and get the right amount of plywood for the job. You will need to be sure to measure from the back wall to the very middle of the flange. Then measure from the side wall back to the middle of the flange.

Step 2 – Piping

Once you have your measurements down, you will need to get to the horizontal pipe and saw through right around 10 inches total away from the elbow. The pipe will then need to be sealed temporarily.

Step 3 – 2x4s

You will need to get 2x4s that can fit along the joists along the edges of the hole. Using long wood screws and your screw gun, you will need to attach the 2x4s so that they will be able to create a shelf for your plywood.

Step 4 – Plywood

Your plywood will need to be laid down next. You will need to be sure that your plywood is the right size and shape for the hole. Mark the plywood with the measurement you took in Step 1. Screw the plywood down onto your 2x4s to secure the new subfloor.

Step 5 – Tile

Once you have your plywood laid down and secured, you will be ready to lay your replacement tile down. Use your tile nippers to make sure each piece of tile will fit into the area surrounding the toilet flange. Once the tiles have been laid, you will need to let them set overnight to make sure that they are completely dry. Once you have done this you will be able to grout the tiles. The grout will also need a day to dry. Once you have successfully finished all of this you will be able to use your toilet again.