How to reinforce shower pan threshold?

[127bit]

The left rear floor corner is highest (the shower pan touches/sits on the floor), sloping down diagonally to the front right corner (lowest). The front right corner shim is 5/8", the left front corner is 3/8" shimmed, with shorter shims under left middle and right rear corner.
The pan perimeters are level and ready for the mortar to be applied to the underside. However, I don't know how to support the threshold flange, especially as the gap below it is a gradual wedge shape. I think that if the threshold is not properly supported, it would begin to crack as it is periodically stepped upon.

1. Should I form a mortar mini-curb to be vertically flush with the threshold to avoid trapping water on a 'step'.
2. Would forming a mortar mini-curb at that location not gradually wick water under the pan?
3. Might stepping on the threshold not eventually crack the mini-curb?

Advice here will be most appreciated.
Thank-you

 

[bud16415]

Welcome to the forum.



I think I would with that much slope build a dam across the front edge and pour a self-leveling mix in and create a level flat surface to work off of. Then when setting the pan use some stiffer mortar ad a bedding material to support the pan. I have never done this so others could well point out problems doing this. I have seen it done when setting one piece shower tubs to add support below the floor.



The product that comes to mind is called cement-all.

 

[DIYRepairEnthusiast]

Hey, there.

One solution could be to use mortar to create a small curb that's level with the threshold. This can help support it and prevent water from pooling. However, you'll want to be careful not to create a space where water can get trapped under the pan.

To avoid this, you might need to seal the joint between the curb and the threshold with a waterproof material. Reinforcing the curb with strong materials like mesh or rebar can also help prevent it from cracking if someone steps on it.

Make sure to also keep an eye on the area for any signs of damage and fix them quickly. Good luck with your project!

 

[127bit]

Conclusion: I stuck a strip of painting tape along the threshold, flush with its bottom edge. Then I set the bed of mortar including a curb about 1.5 inches deep straddling the threshold bottom. Levelled the pan, waited about 2 hours, then scraped the excess curb away, leaving its face flush with the threshold bottom. After its fully dry I'll pull the tape off and probably press a bit of caulking along it once I've got the floor prepped later. Thanks for the suggestions.