I am re-doing a bath in a loft with a concrete floor. I would like to have a shower base that is flush with the old concrete floor - and that makes sense to do because I have to cut the concrete to position the new drain anyway.

Does anyone know the pluses and minuses of casting a shower base in place. It would be built just like a base for tile, with a rubber liner. But instead of tile, it would just be concrete, sloping from the existing floor to the shower drain.

Thanks for your help.

I have seen it done both ways. Make a cut out for the base, install a floor drain in the center and a little under the floor line and repour the base sloping to the drain. The advantage to this method is that floor drains do not have to be vented. The down side is that you will have to pour hot tar on the floor for a seal before you pour cement and slope to the drain. If everything's not water tight you could have some seepage. *** OR***
Make your cutout and install a flange type shower drain,(see image) and a shower pan that you can then pour cement and slope to the drain. The advantage is that you're sure that it won't have seepage4. The downside is that if the shower isn't vented you will have to vent it or make sure it's connected to the lavatory drain line where it will be wet vented.
The easiest is door#1, the safest is door #2. your choice, Good luck, Tom

I have seen it done both ways. Make a cut out for the base, install a floor drain in the center and a little under the floor line and repour the base sloping to the drain. The advantage to this method is that floor drains do not have to be vented. The down side is that you will have to pour hot tar on the floor for a seal before you pour cement and slope to the drain. If everything's not water tight you could have some seepage. *** OR***
Make your cutout and install a flange type shower drain,(see image) and a shower pan that you can then pour cement and slope to the drain. the advantage is that you're sure that it won't have seepage4. The downside is that if the shower isn't vented you will have to vent it or make sure it's connected to the lavatory drain line where it will be wet vented.
The easiest is door#1, the safest is door #2. your choice, Good luck, Tom


Thanks. Option 2 works for me since I have to cut into the existing floor anyway. By the way, the concrete floor is on grade - only dirt below -- any problems with that? Also, will concrete without tile or some other finish hold up as a shower base. The entire floor of the loft is concrete, so it would be great to have the shower of concrete, too. Thanks again.

A "loft" to me indicates a 2nd. Or 3d. Floor installatioin. If you're on the grownd floor with dirt underneath then you have the perfect set up for door #1. we had a basement shower like that in the house I grew up in with,( a floor drain set in the slope of the floor), no problems. Why complicate things? Regards, Tom