How To Prep For a Walk-In Hot Mopped Shower Pan Part 1
So many designers and architects are now wanting the look and feel of a curb less entry into the shower. With out a doubt it is becoming more common, not only in new construction but especially in the remodeling industry.
What is amazing is that so many times no thought is given on just how to achieve this effect!
Many things need to be taken into consideration before any shower area can be made into a curb less, walk-in shower! With the event of the ADA into code, most commercial enterprises learned how to incorporate the curb less shower pan into the areas needed on there project.
The home and bathroom remodler wants to give thier clinets what they ask for but more often than not don't anticapate the amount of planning it take to achive a walk in, curb less, shower pan.
The most important thing to remember that the shower pan area needs to be lower then the floor around it! That means that the shower pan floor it needs to be recessed. The amount of recess will depend on not only the size of the shower pan but also the location and type of drain.
In this photo of a 3x3 shower the drain is a commercial adjustable, center placed. Which makes the 3" recess the slab was poured at, more than enough. The formula to use for getting the proper recess is: A-from drain placement to the most distant point of entry in feet; multiply this by a 1/4" then add a 1/4" that will be for the hot mop pre-pitch, B-add 1" for mortar bed, C-add thickness of tile, D-add 1".
So a 5x5 shower pan with a center drain would be: A= 2.5 x1/4= 7/8" to 1" + 1/4 = 1-1/4 " + B- would come to 2-1/4" + C-(say 1/2") would come to 2-3/4" + D would come to 3-3/4" recessed pan. That is th minimum depth your recessed pan needs to be. Hint: Per code the drain top needs to be a minimum of 2" lower then the finished height of floor. That is why an adjustable drain style is the way to go as it give you the advantage of 1" change of depth. Now if your drain placement on the same 5x5 shower pan was at the far wall the "A" dimension would change to 1-1/4" (that is 5' x 1/4") which would bring the depth to 4-1/4". The 4" recess would work if an adjustable drain was being used!!! A 4" recess can do up to a 5x5 pan... a 3" is just enough to a 3x5 with any drain placement and should be the minimum depth on any recessed pan...
Wood framing for the sub floor of your hot mopped shower pan needs to follow the same mathematics as for a ground level concrete sub floor...and in remodel or renovation construction this can pose a problem. To achieve the recess the height of the floor joists needs to be lower than the surrounding floor.
In this photo you can see that the builder was able to keep the shower sub floor 2-1/2 " lower than the surrounding floor. With the drain at center and changed to an adjustable screen height style, with an EBBE Hot Mop shower adapter, we were able to make this shower pan worked for the builder. This was new construction and was thought out from the on set and with just the minimums achieved but successful!!!
Without the benefit of starting from scratch as with remodeling your existing bathroom, a number of things need to be taken into account. If you plan to trim or replace the framing members you shower pan, are they going to be strong enough to bear the load? Is there other construction that needs to be moves? A/C ducts? Plumbing? Electrical? Can the finished ceiling below be removed for easy access and re-build? As you can see there are many considerations when you or your customers want to have the look and feel of a custom shower by giving it the curb less walk-in beauty. More in our next blog on this topic and how to go about it in the remodeling of your bathroom!!!