Hi Everyone,
It's been a few months since I've been around here, as unforeseen circumstances have kept us occupied, but I started working on the shower for our master bath again a few weeks ago. To bring everyone up to speed, I have completed everything up to hanging the concrete board, finishing the mortar bed, and building the curb. However, the curb is where my problem lies.

I built the curb a week ago, as best as I could from the instructions in the "Building a shower pan..." picture tutorial by Harry Dunbar. I used "SAKRETE TYPE-S high strength Mortar Mix" mixed with a similar consistency of the deck mud (balls up in your hand leaving it dry, and easily crumbles). It was my first curb, and it took probably 1.5 hours to do it, but when finished it looked really nice. Very straight, uniform in height and width, nice square edges, and a slight slope into the shower.

However, now a week later, I still can't help but think that something is wrong. The curb is surely dried by now, but I can touch spots of it, and still have mortar mix easily scrape away (similar to the finished mortar bed), or have little pieces "crumble" off, or knock little pieces off the nice clean edge. Surely the curb shouldn't be like this... should it?!?!

What's happened? Did I do it wrong? I'm fairly sure the mortar mix I used is the stuff I'm supposed to. Did I just mix it too dry? I did notice several times when building the curb that if I wasn't very careful, and didn't pack the mortar pretty hard when building it, that it would just crumble and fall apart... is this a sign of too little water? I didn't want to put in more water, because I didn't want to ruin it. If the mix was too dry, is it possible for me to wet the curb over and over again over the next few days and see if it'll soak it up or is it too late? Does this have nothing to do with the water/consistency at all?!?! Do I have to tear this curb back out?!

I'm so confused, because when i did the curb, it seemed like it went smoothly, and looked great, so it finally seemed like a job well done on this project.... but now this.

Any and all ideas and advice greatly appreciated.

Thanks so much!
JackOfAllTrades
(Master Of None)

No one here has ever seen anything like this, or has any advice for me?! Still stuck here at this point in the shower and looking for help!!

Thanks.

Judging from your description of the curb mix I would say it was too dry. The curb mix should be slightly wetter than the shower bed mud.

You can't add water to it now. It's too late for that.

Tear the curb mud out and redo it with a wetter mix than your floor mix. You may or may not have to replace the mesh depending if the mortar stayed in the diamonds. You need clean mesh for the new mortar.

Mortar-Mix should be spread into the lath and not packed. Not too wet ... just wet enough to cling to the lath.

I always build the curb last so that it has no wear and tear to damage it because as you noted .... it can easily crumble when banged or scuffed with boots (even perfectly mixed mud). If it isn't too damaged you may be able to repair it with thinset mortar, otherwise .... Randall's suggestion.

Goodluck

Thanks for the responses guys, but I'm still a bit confused.

RC, if the curb needs to be rebuilt, and if the lath needs to come out (neither of which I am sure of at this point), how can the lath be pulled out without ruining the mortar bed at this point!? Or would that mean having to redo everything on top of the waterproof membrane?! Obviously not my first choice!

Harry, I built the curb last, and I have not walked on it or near it, so there is no damage from that, but after sitting and drying this whole time, the curb still can crumble to the touch in spots. I can't imagine that this is normal. You say that it can crumble when banged, but surely not just to the touch or flick of a finger?! I haven't tried, and don't know if I should, but in this state, should I be able to stand on this curb?!

I'm starting to wonder if I should just find someone in my area just to come out and take a look at everything I've done to make sure it's all right, and possibly redo the curb... only because I'm getting real tired of wondering if everything is done properly, and have virtually no time (full time college/full time work/and remodeling/with baby on the way).... so second guessing everything kills what precious hours I do have. Anyone know of a GOOD shower guy in the Niagara Falls area (on USA side... so passport would be a must) who is VERY FAMILIAR and competent with this process, perhaps that I could hire for half a day to a day just to evaluate/fix curb/and advise? I guess just feeling overwhelmed! Ahh!

Thanks for the advice guys!

To get the lath out you need to cut it out about 1-1/2" to 1" above the shower floor. Once you unattach it from the front of the curb bend it back towards the shower. Now with the tip of your wire snips start cutting the wire at the desired height. Be careful not to catch the liner.

Try to flatten the strip you have on the shower side as best as possible. Now form the new mesh to fit down behind the the strip you left on the shower side. Renail at the front of the curb only.
Do the curb mix again but make it a little wetter than the first time.

The other option would be to remove as much of the mesh as possible along with all the curb liner that's on the top of the curb and the front side only. You are going to cover the curb sides and top with strips of 1/2" cement board. The strip on the top needs to be set in thinset with a 1/4x1/4 trowel. Use 1-1/4" cement board screws to fasten the new pcs. Buy some RedGard liquid waterproofing from Home Depot. You will cover the curb and 3" out on the shower floor with 3 coats of the liquid.

PM me about a site visit.

RC,
Thanks for the info. Although it may have to be redone, it seems like the concrete curb is still the way to go... I mean it is the stronger, and more preferred method, right?! I'd rather have it done right the first time!

Oh, and I sent you a PM.

Thanks!