Curbless Shower

[Freddie]

I am looking at options for my ensuite bathroom in terms of a new shower. My wife would love a curbless shower. Anyone familiar with the plumbing code in Ontario (specifically Ottawa) that could help clarify what is code and what is not? Here are some items that I’ve narrowed down from research online and from discussion with reps at plumbing stores.

1. Slope of shower pan must be between ¼ to ½ inch per foot.
2. Flood test needs to be done to verify shower pan waterproof integrity.
3. There must be at least 2” of water hold above the top of the drain either via a shower curb through the slope of the shower pan.
4. The curb must be at least 2” and no more than 9” and be at least 1” above the adjacent shower floor
5. Showerheads cannot be aimed at the shower door. (Might just be common sense)

The only other question I have is:

If you have a curbless shower what defines the edge of the shower and thus the edge of the sloping floor?

[jadnashua]

There may be exceptions for curbless showers...in the USA, it would be the ADA guidelines...not sure if there is an equivalent in Canada, but suspect there is.

[johnfrwhipple]

We build curbless showers every month here in Vancouver and not once has the 2" rule ever come up. This reference is to a IRC Building Code enforced in only a few US states. Your curbless shower grading should be based on the flow rates and types of shower fixtures you plan to run.

5/8" is a key number I measure on many jobs in respect to water level rise above drain grill height. It seams to be that this rise is he max rise in shower water levels with flow rates in the 4-14 GPM.

What kind of flow rates are you having in your project?

Do any of the fixtures spray water directly on the drain location?

JW

[Freddie]

We build curbless showers every month here in Vancouver and not once has the 2" rule ever come up. This reference is to a IRC Building Code enforced in only a few US states. Your curbless shower grading should be based on the flow rates and types of shower fixtures you plan to run.

5/8" is a key number I measure on many jobs in respect to water level rise above drain grill height. It seams to be that this rise is he max rise in shower water levels with flow rates in the 4-14 GPM.

What kind of flow rates are you having in your project?

Do any of the fixtures spray water directly on the drain location?

JW

Hi John,
Thx for the feedback. Don't know the exact flowrates but at most there will be 2 showerheads on at one time( rainshower and handshower). I currently have 1/2 lines to the shower but was thinking of upgrading to 3/4" as it is located on the far side of the bathroom and supplies the whole bathroom and would allow both showerheads to run at the same time. If that might cause some problems I'd contemplate not doing that.

If I use a center drain then both fixtures will or could hit that drain. With a linear drain at the entrance, handshower might hit the drain but most likely not.

I responded to another message of yours on this forum with a picture of my room. It is identical to the picture you posted to the message board.
http://www.terrylove.com/forums/show...s-shower/page3

My plumbing is on the same location in the shower and we are thinking of an V&A Ios tub next to it. My two options are to use a center drain like you have done but not sure I have the vertical height to do that. I could drop the flooring down by 5/8" to in between the top of the joists; that would give me 1 5/8" to top of bathroom threshold / current tiled bathroom floor. Not sure if that is enough space to get the center drain in above the floor and then add the necessary 3/8" minimum slope (3' x 3' shower) or 5/8" as you suggest.

Option #2 was to put a linear drain just inside the door to the shower and slope the floor up from there. That would mean a curb on the left side of the shower but if option #1 does not work out then it's better than curb all around at least.

I appreciate any advice that you may have. I may contact the local city plumbing inspector to ensure all this will work once I finalize and to ensure that there is nothing funny in Ottawa that is different that anywhere else.

[jadnashua]

You need more depth than that with any system you might use, and way more if you tried a conventional shower. A mudbed where you used a tileable membrane over a wooden subfloor needs to be close to 1" thick at the drain and rise from there. A conventional shower construction where you have a preslope, liner, then mudbed, would typically need to be over 2" at the drain and a little more wouldn't hurt. The membranes aren't designed for direct application to ply and cbu might be problematic on the floor of a shower, so that leaves either something like the Kerdi pre-formed foam pans, Wedi preformed pan, and maybe some other technique. BTW, Wedi makes some neat standalone showers - one I particularly like is the scroll.

[Freddie]

jadnashua,

Yeah I understand that it will be tight but on preliminary research, looks like the Kerdi linear drain will be about 1" to the top of the channel body then add on the tile and thinset. So could easily be done. Not that I want to use the Kerdi foam system.

Do you see any problems with having a linear drain just inside the door of the shower, at the same height as the bathroom flooring, and then have the shower floor rise up from there? This is my option #2 if I cannot go curbless. This would also allow the door to swing out without any problems concerning interference with the floor.

[jadnashua]

You don't need to use the Kerdi foam pan, you can construct it out of mortar but the mortar needs to be at least 1" thick over a wooden subfloor. That would mean you'd have to raise the floor height outside of the shower at least that level. You might get by with it being slightly less, but it's risky. I don't know if Schluter would warrant you doing it with cbu. Since it would be a sloped, but flat surface...you might get away with sloping the subfloor then using cbu on top of it, then Kerdi (and likely Ditra outside of the shower). Using Ditra inside of the shower might allow you to go directly on the subflooring, but it makes it harder to seal around the drain...possible, but tougher and definately non-standard.

You have to get your inspector to approve this non-standard thing, and you may have no warranty from Schluter. I'd suggest you contact them for thoughts.

Wedi is pretty neat stuff, and it is designed to go directly on plywood without fasteners - sort of like a big tile. You can buy that in very thin panels. You'd need to be very careful about getting your thinset nice and even as those really thin panels may not lay flat after you walked on it with the wet thinset underneath. You might want to use something like a lawn roller to embed the stuff and keep it flat. Just brainstorming here. Your best, approved method would be to recess the joists - raising the floor makes the transition into the room awkward.

If you had good waterpressure, with the shower sloped towards the outside, I'm not sure you'd catch all of the runoff in the drain. That's why they typically put it against a wall. If a low hump was acceptable, that should help to contain it, but that would take some skill to both construct and to tile over so it had low lippage and looked good.

[Freddie]

If you had good waterpressure, with the shower sloped towards the outside, I'm not sure you'd catch all of the runoff in the drain. That's why they typically put it against a wall. If a low hump was acceptable, that should help to contain it, but that would take some skill to both construct and to tile over so it had low lippage and looked good.

Good point, and with JW's mention of 5/8" water level over the drain....looks like maybe curbs all around unless I cut down / double up on the joists and that is a big job.

Yeah, threshold to bathroom is about 1" above the top of the floor ( I don't want to raise that at all) which I should meet in the rest of the bathroom with 1/2" plywood, infloor heating, ditra and tile. Sound about right for 1"?

[jadnashua]

Depends on the thickness of the tile and the heating - you may be higher than your 1" total. It's much easier to float slc over the heating mats to encase them verses trying to do it in thinset. SOme tile by themselves are 3/8-1/2" thick, then add the thinset to hold it, about 3/16+ for the Ditra and the ply...

[johnfrwhipple]

Don't know the exact flowrates but at most there will be 2 showerheads on at one time( rainshower and handshower).

With 1/2" lines and both fixtures installed you should be running at about 3.5 - 5.0 GPM. This would be if the restrictors are left installed with these shower heads. Wit hrestrictors removed you might be closer to 7.0-14.0 GPM with both fixtures running.

I would ensure you have a good 5/8" drop from the wet zone to the top of the drains grill. Careful if you select a tile top point drain since many of these can suffer from an air lock and have slower flow rates that a regular drain that has holes through out the design of it.


I currently have 1/2 lines to the shower but was thinking of upgrading to 3/4" as it is located on the far side of the bathroom and supplies the whole bathroom and would allow both showerheads to run at the same time. If that might cause some problems I'd contemplate not doing that.

Can you control the flow rate of your separate shower fixtures. If not I might leave the 1/2" lines in place.


If I use a center drain then both fixtures will or could hit that drain. With a linear drain at the entrance, handshower might hit the drain but most likely not.


Again watch out for a tile top drain if a point drain center location is used. A linear drain at the shower's entrance is a tricky installation and we prefer to avoid this layout when possible. When we do we like to have grade outside the shower back into the shower. If no door is used then the splash zone should be factored in. A change in grade right at the drain can keep more water in the shower if the hand held spray is shot across the floor. You might consider having a 3/14" change in grade just at the drain location (dry side). This instal is working great for us and offers up a lot of safety.

I responded to another message of yours on this forum with a picture of my room. It is identical to the picture you posted to the message board.
http://www.terrylove.com/forums/show...s-shower/page3

My plumbing is on the same location in the shower and we are thinking of an V&A Ios tub next to it. My two options are to use a center drain like you have done but not sure I have the vertical height to do that. I could drop the flooring down by 5/8" to in between the top of the joists; that would give me 1 5/8" to top of bathroom threshold / current tiled bathroom floor. Not sure if that is enough space to get the center drain in above the floor and then add the necessary 3/8" minimum slope (3' x 3' shower) or 5/8" as you suggest.

3/8" is to scary - no room for error here. Sometimes the shower water rises 3/8" before the weight of the water balances over the drain grill and the natural max flow rate is achieved. It could work but it is quite easy gaining a little wiggle room between the floor joists.

Option #2 was to put a linear drain just inside the door to the shower and slope the floor up from there. That would mean a curb on the left side of the shower but if option #1 does not work out then it's better than curb all around at least.

In the shower you see of mine I recessed the shower area and surrounding 12". We have 6-8" of grade outside the shower back to the door. You will notice the mitered tile trim outsie the glass to allow this back pitch. The Schluter trim is 1/8"-3/16" higher that the trim tile. This is a baby dam that prevents water travelling down the shower door from skirting out the shower. We have no deflector on this door and the door is raise about 5/8" off of the shower floor. This allows the door to open into the bathroom and clear the shower mat. With no deflector water hitting the door will run in both directions to a certain degree. I've seen it run 7' on projects with direct contact from the hand held!

I appreciate any advice that you may have. I may contact the local city plumbing inspector to ensure all this will work once I finalize and to ensure that there is nothing funny in Ottawa that is different that anywhere else.


Hope that helped somewhat and not confused you more.

JW

[johnfrwhipple]

Here is a closer picture of the detail we incorporated into this curbless shower. This detail offers up more safety from water escaping. This is a hair low and we are since installing them a touch higher. The look is great and the function - BRILLIANT

JW

[johnfrwhipple]

You can see the dip in the shower floor at the drain location. This is a Kerdi Drain and I lowered it between the floor joist somewhat. Loads of work is needed to beef up these subfloor when you will be using thin levels of mortar and setting materials.

For this Kerdi Curbless we installed a layer of 5/8" sheathing level with the floor joists tops and then another layer of 5/8" plywood on top. No where under this tile install is there less than 1 1/4" of plywood.

Sometimes we do this work in the primary wetzone and then outside this zone install some 1/2" cement board. With the extra 1/2" cement board and the recess at the drain location those key heights come to be. Of course the size of the tile and type also factor into the equation.

No matter what you do insist that this work is flood tested for a good 1-3 days. No sense moving forward until the work is tested and signed off on by the local city inspector.

Is this bathroom being inspected by the city? Is it in a commercial property or a private home?

JW

[johnfrwhipple]

Lip at linear drain.





This lip is located about 6-8" from the shower's bathroom entry door. To prevent water from sneaking along the edge the drain was installed before the wall tile and brought right to the back wall. Then the tile notched into the drain base. The Schluter profile is set higher than the drain and works well at blocking water from sneaking out. The linear strainer works well bring the water flow into the drain. Other drain styles can offer up a little room for water to skirt over them.

This is a far as we pushed the limits and was installed here in Burnaby under city of Burnaby plumbing and building inspections.

JW

[Freddie]

Thanks for the great advice in your response and the ideas in the following pictures. This will certainly help me.


With 1/2" lines and both fixtures installed you should be running at about 3.5 - 5.0 GPM. This would be if the restrictors are left installed with these shower heads. Wit hrestrictors removed you might be closer to 7.0-14.0 GPM with both fixtures running.

Restrictors will be left in as we have one of the first tankless water heaters in Ottawa. Heater is limited to a max flow anyways.

Can you control the flow rate of your separate shower fixtures. If not I might leave the 1/2" lines in place.

I plan on doing that so that when we switch from handheld to rain shower we don't shut off the water supply even for a second. No flowrate or actually <0.5 gpm I think means that the tankless water heater shuts off.



With no deflector water hitting the door will run in both directions to a certain degree. I've seen it run 7' on projects with direct contact from the hand held!

I could run any waterproofing out underneath the exterior flooring as a help. I also plan to have Ditra under the external tiles along with in-floor heating so that could be a challenge to make sure water stays off of the infloor heating. Or does it really matter?

[Freddie]

Is this bathroom being inspected by the city? Is it in a commercial property or a private home?


This is a residential property and I'm still waiting for the inspector to get back to answer some questions and to find out exactly what needs to be inspected. I do know that a plumbing permit is needed for any plumbing changes and I will have a few but hopefully that is all they are concerned with.