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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Hammer drill makes removing old shower pan much easier

If you use a handy power tool like this hammer drill and chisel, your mud shower pan floor will soon be chunks of rubble. (Tim Carter)
By Tim Carter Tribune Content Agency

DEAR TIM: I’ve decided to do a major bathroom remodel job. One thing that needs to be demolished is a full ceramic tile shower with a seat and a concrete mud floor. I’m feeling pretty good about removing the tile from the walls and ceiling, but I don’t know the best way to remove the tile floor and the concrete mud floor. What tips can you offer to minimize the pain both to my body, the family and our possessions? – Mark P., Tampa, Florida

DEAR MARK: You’re about to undertake a nasty job that few look forward to. The good news is that if it’s a standard-sized shower, then you’ve only got about 10 square feet of misery to face.

I’ve demolished my fair share of these mud shower pans over the years. The most recent one was installed by a negligent builder and tile setter over a concrete basement floor with no waterproof membrane whatsoever. This shower also had a seat in it, and the water flowing over the seat entered hairline cracks under the front lip of the seat and leaked, causing all sorts of wood rot and mold.

If your new bathroom is going to have a new tile shower, the tile needs to be placed over a waterproof membrane or prefabricated shower-base system that directs all water that leaks under the tile back into the shower floor drain, just as a hard china or stainless steel sink works in a bathroom or kitchen.

Don’t ever let a contractor tell you that caulking used in conjunction with cement board or water-resistant gypsum board is sufficient to prevent leaks. There is no substitute for a waterproof membrane under the mud floor or shower seat upon which you lay the tile.

To remove your current mud floor here’s a partial list of what you will likely need:

A four-pound hammer

Assorted pointed masonry chisels

Work gloves, goggles, dust mask and hearing protection

Powered rotary hammer/chisel tool

A hand-pump garden sprayer

Years ago, I removed the first mud pans of my career by hand. It was mind-numbing, brutal work. Fortunately, manufacturers created tools that resemble miniature versions of the jackhammers you see road workers use to break apart concrete slabs.

You can rent a hammer drill. It will transform the mud shower pan in your bathroom into small, baseball-sized pieces of rubble in minutes. I prefer to use a pointed bit to start the job.

The job goes fast if you have at least one side of the shower pan exposed. This is almost never the case; a shower pan is typically boxed in by three walls and a stubby curb. If you can figure out a way to remove the curb you step over to get into the shower, the demolition of the mud floor will proceed much faster.

When you have at least one side of the mud floor exposed, start to chip about 1 1/2 inches away from the edge. The mud and tile will now have a place to move to. As the pounding bit drives down into the slab, it pushes freed chunks of concrete to the side. If the mud pan is locked in on all four sides, you can see that this movement can’t happen.

If you can’t open one or more sides, then you should start to create a hole near the shower drain. Use a garden sprayer to keep the work area wet to keep the dust to a minimum. Plug the drain hole of the shower with a rag so no cement sludge or bits of tile or concrete get into the drain system.

Once you create the hole, then you can use the same procedure as described above: Place the tool bit near the edge of the hole and break off small chunks in the direction of the hole. When the hole gets to be about 1 foot in diameter, you’ll notice the work will proceed at a much faster rate.

Be very careful when first operating the power tool or even when using a hammer and chisel. When you strike ceramic tile hard, it almost always shatters and small pieces of sharp tile go flying. I’ve been cut more than once by these very sharp shards of tile. This is why safety glasses are a must and goggles are even better. A trip to the emergency room to remove a piece of tile from your eye could easily cost you more than $1,000.

Don’t underestimate the ability of dust to travel through your home. This fine dust can harm people, animals and your possessions. If you can enlist a helper to keep spraying water as you work with the other tools, that’s best.

Be sure to put down drop cloths to protect nearby floors from the small pieces of grit that get produced by all this mayhem. To help motivate you, remember that jobs like this not only build muscle; they also build vast amounts of character and give you bragging rights at the next neighborhood barbecue.

Need an answer? All of Tim’s past columns are archived for free at www.AsktheBuilder.com. You can also watch hundreds of videos, download Quick Start Guides and more, all for free.