Barrier-Free Safety Design Guidelines (safe guarding your hobless - no dam - no curb shower)

[JohnfrWhipple]

Over the years my design style for curbless showers keeps changing. This is because with every new job I get better, I learn more and have studied more. With each passing month I have helped more people and learned of more hurdles to over come. Basic principles start forming. These get refined and then I make up rules of sorts. Not TTMAC rules. Not TCNA rules. My rules. And the first one is a big one.

One of my golden rules is that a shower should always be able to hold 1" of water above the shower grate before things go horribly wrong. There are many reasons for this but the primary reason is that it takes on occasion a little head water build up above a drain before a drain starts meeting it's max flow rate.

Some drains work fine with 3 gallons of water per minute. Same drain with 12 gallons per minute might see a head water build up of 3/8". Add a hand sprayer to the mix and change to flow pattern on the floor and then you might see 5/8". These are tough lessons to learn in the field. When you learn them - it's costing you money to fix.

So - I follow my rules and one of the big ones like I said is the 1" rule.

In the photo below you can see my nasty 4' level.


It's sitting on the ACO shower drain with a stack of tile. The tile is 3/8" thick. Plus a 1/8" red shim. So I have just over an inch. The level reads level in this photo so I can measure the grade change.

To gain this measurement I need the help of my capillary break (shown to the right). A capillary break is another rule and one I can cover later.

RULE #1

Have at least 1" of water build up in the shower before the
"OH Shit Point!"
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[Eurob]

Just for a clear understanding , the 1'' of water build up in John's example is only present at the grate .

It is reducing in height where the shower limit -- 4' way from the grate -- and becomes almost none existent , depending of the outside of the shower area grading .

Well done John.

 

[Sponsor]

 

[JohnfrWhipple]

Yeh Roberto. Once the water hits the top of my capillary break it can go anywhere upstairs.... If it breaks the capillary it is all going to shit. The door to the bedroom is less than 2' from the shower. High risk!

I have a good inch to the top of the tile at the capillary break and then another 3/16" roughly. Inside the shower a good 1". The baby dam should hold back any hand held spray or door run off.

Body jets are aimed to the tub deck.

Can't wait to juice this sucker up and see it in action!

 

[JohnfrWhipple]

I'm going to install an "Anti Air Lock" ring on this ACO tile grate top. I do not like tile insert grates used on barrier free showers.

I am also not including a hair strainer! no way no how......

RULE #2

No Hair Strainers on Barrier Free Showers​

This little hair strainer is great. But it will catch hair. The more it catches the more the flow rate will drop. With no curb to let your ankles know they are getting wet a build up of 1.5" of water can spell disaster for your barrier free shower build.​

 

[Eurob]

Looking forward to see the updates ... more action Baby !!!

 

[JohnfrWhipple]

Looking forward to see the updates ... more action Baby !!!

LOL - I sent one video to my wife (time lapse) and she replied "Work Faster" !!! LOL

 

[Eurob]

LOL - I know the feeling !

 

[JohnfrWhipple]

Capillary Break and Baby Dam
Rule Number #'s 3 & 4
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If you plan to build your shower by the book then please skip this post. These rules are my own and are influenced by my prior work. My past shower design failures and Australian Waterproofing Code. Kind of. They show my take on a capillary break and my baby dam design. In the picture below I have a stainless steel (5/8") tile edging transition sealed to NobleSeal CIS (blue) shower waterproofing membrane.

Some key points to look at.

Large tile is a hair higher than stainless steel edger.
Small tile is graded to shower.
Small tile is 3/16" lower than stainless steel edger.
​

This is my design. My secret ingredient. I designed this years ago while flow testing a barrier free shower. The shower worked great until the hand hand sprayer was used. Then shit went wrong fast.

You need to understand the effects of shower spray on your shower's entry glass door. Until you have studied this in detail (like me). The benefit of these two rules will not become clear. AS for capillary breaks... They are very important as is weep hole management. What you can not see in this photo is the path the water can take to the drain below the mortar bed.... ​

 

[ShowerDude]

Great points here ....I have learned so much about curbless builds these last 3 years or so. everyone unique and its own set of challenges.

So Important the cappilary break installs prior to the flood test..(or of course a temp damn as John has covered many times.)

On this curbless minneapolis area shower build I screeded the bathroom floor just a hair high out side of the shower. This builder had left me a nice 4x7 recess . This made this job flow well. We achieved about an 1-7/8" drop from entry to drain.

since the entire bathroom floor screed is a hair high , I later snap a line and use my hand stone to back pitch the entire wall to wall entry area by 1/16"-1/8" ( Black line in pic) . Later after my Waterproofing extends past this The glass channel was set in silicone acting as the cappilary and got tiled in..

This shower would be nearly 2" deep by the time the water could get past the glass and onto the bathroom floor... with flow rates considered this would take some time to overflow and at that point would be operator error IMO !!! (for not paying attention to the dirty clogged hair strainer!!!!!!) in this case it would overflow onto a 1.25" mud floor set over waterproof wedi board before it gets to the subfloor plywood.... the hydronic in floor heat would help accelerate the dryout.........LOL!

level and properly graded screed is a key point...easier said than done. Some people would have you think its all to easy to build a proper curbless shower.......



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[JohnfrWhipple]

Yesterday I humped in 20 boxes of tile. About half the tile for the project. Each packaged bundle had two boxes of six tiles. I started feeling blue that the work was so hard. So heavy. Then I wimped out and took the tile one box at a time and split the straps at the truck.

That's when I say that each box of 6 weight 48 pounds. I made four runs with 96 pounds and 16 with 48. Three flights of stairs is no fun.....

Lots happen behind the scenes on a nice looking tile job. Most times it's hard work and imprevession... I later set 30 square on the master bathroom floor.. Some how the floor cam out level. Not sure how without any lashing system in place! lol