Shower build - Curb help and advice needed

[Waterbound]

Hi everyone, great site you have here which has been tremendously helpful!

We have decided to renovate our shower and following all the steps from here and everywhere, I think we are in good shape so far. We have completed the pre-pitch mortar pitched as required etc., and now at the point of determining how to complete our curb after we complete the liner install.

Originally, we intended to use a curb system such as kirb-
perfect in combination with the pitch rails for the final bed and trying to decide on how to finish the curb. I have seen videos where someome simply made a frame with two pieces of wood and filled with the mud etc., after setting, the curb was completed and ready to go. We have two curb systems to choose from, one is shorter than the other but the same basic principal for install. For one system, the instructions indicate to bring the liner up between the curb system, attach and fill with mud., fill the sides and top etc., essentially covering the frame system. The other larger system indicates okay to use with or without 2x4s but appears to be made to install over a 2x4 curb build. It seems easier to build a frame with two pieces of wood and fill with the mud then remove the wood sides and be done.

The curb would be built on top of the pre-pitched mortar and sides would be protected as needed. If I were doing this from scratch again, I would have gone the route of making a curb from 2x4s and attached to the subfloor but we are here now and hopefully one of these options is viable?

For specifics: The shower is approximately 3'x3', I added studs to allow CBU install and plan to redguard the CBU once completed. Pre-pitch was originally started using one type of system which failed misserably so we tore it all up and started over. We used tar paper etc.,and pre-pitch is level on all sides with required pitch. Also had the old valve replaced and new hardware. We are planning to use the rail pitch system for the final pour to ensure the correct pitch is completed with weephole protector etc., but just down to final option on the curb so any advice would be greatly appreciated so we can actually get this shower completed!

I have also attached a a picture of the two curb systems, note that we have two of each as they are both only 24" in length. I just question how easy it would be to actually fill the curb system with mud vs. simply building a frame and filling with mortar. Some of these systems sold by tile specialty store are complete trash and it seems they know that as one system we purchase that failed was already taken off the shelf and kirb-perfect was added back again. Also included some of the install pics and again, any and all advice is greatly accepted and appreciated!

Thanks!
Scott

[Gozo]

Welcome Scott. I can't authoritatively answer your curb question, but looking at your pic of the shower valve, I didn't see an access area to get to the plumbing if/when needed. How are you going to shut the valves off?

[Waterbound]

Hi Jeff, thanks for the welcome and that picture is a week old, I have already cut out the necessary access panel for future access but didnt think to take a new picture etc.

I have attached some better pictures of the access panel, curb systems and the pre-pitch system that failed which really was a complete waste of time in my opinion

Thanks for the reply!

Scott

[Davy]

Scott, just a reminder, the mud isn't what stops moisture from getting outside the shower floor and curb, that's the liner's job. We usually recommend mudding the curb with fat mud like is shown in the shower construction thread, you'll find it in the liberry.

[Waterbound]

Hi Dave, thanks for replying and definitley understood!

My question is really what is the easier method to build the curb; using two pieces of wood as a frame and use it as a curb mold or using the plastic curb system where the liner is attached on the inside etc. Note that I fully intend to waterproof and complete the necessary steps to ensure the barrier works no matter which method I use to build the curb. And the curb will be built on top of the pre-pitched mortar otherwise I would have just built a curb out of 2x4s but the mortar is laid so I am committed to building a curb or ripping it out and building a 2x4 curb which is not what I want to really do

The kirb-perfect setup is made to install over (3) 2x4s but they indicate it can be used as a stand alone setup to aid in making the curb. I am concerned how easy or hard it would be to use either of the curb setups to build my curb. I hope what I am saying makes sense

I saw that the curb instructions in the liberry indicate the core was made out of 2x4s, I have found very few instructions on how to make the core of the curb after the pre-pitch is completed. The only methods I am aware of are building a frame with two pieces of wood and fill/pack with mud, or use the curb system without 2x4s and lock the liner in between before its filled with mud etc. If I have to cut it out and start over, I will etc., just hoping I have options on building the curb core.

[Davy]

I've never used the plastic form like you have so I can't say much about it. I think you'll need the 2x4's so you will have something to support and hold the pan liner up. You will also need the formed pan corners where the jamb meets the curb. These are important. Once the pan liner and corners are in place you probably can use the plastic form.

[Waterbound]

since the pre-pitch is already done, is there any way to make a curb with 2x4s and install on top of the existing pre-pitch bed? I figured if I used plastic curb system I could use the mud which would bond the curb and pre-pitch etc.

thanks again Davy!

[jadnashua]

You could buy a panel of KerdiBoard, cut it into the right size, thinset it in place and have a curb that would work. Depending on how thick you want the curb, you could layer the 2" stuff, for a 4" wide curb, or buy a thinner panel, and use more layers to achieve your desired thickness. There are preformed foam curbs that could be wrapped with the liner, then mudded as well. Or, you could buy some concrete pavers or bricks and build your curb, cover it with the liner, then make it tileable as discussed in the 'liberry' article mentioned. Placing wood on the edge of your preslope probably isn't a great idea. Using something that is inert and not organic is better.

[Davy]

I would cut the preslope out so the 2x4's go right up to it.Then screw it to the floor and jamb. The liner needs to wrap over the 2x4's with no nails in it on the inside and top. Just the outside. Then the lath can be wrapped over the curb. Again, nails only on the outside.

I would make sure the plastic will allow for at least 1/2 inch of mud on all 3 sides and also make sure you have about 1/8 pitch on the top draining toward the shower.

I can see it working but I can't see buying a whole panel of 2 inch Kerdi board just to make a curb. I don't know the price but 2x4's would be much cheaper. Just trying to use what you already have.

[Waterbound]

Thanks for the replies guys! The pre-pitch is probably an inch or so thick where the curb would be installed so maybe I will try to cut the pre-pitch out, hopefully it stays solid. I like the Kerdi board idea as then I wouldnt have to cut anything out. Decisions decisions. I was hoping to fabricate a curb using mud etc., then maybe use redguard etc. I already have the redguard waterproofing and intend to use that on the walls but definitely not the floor etc. I dont mind buying a sheet of kerdi if it will save me time and prevent tearing out my pre-pitch etc., especially if its strong enough etc.