Hi Joe,
I asked Leland Yarbrough, the general contractor to answer your question. Here is his answer:
"The system is a standard "mud pack", nothing fancy or complicated for a experienced contractor or tile setter. Completely proven over many, many years. The transition between the common bathroom floor and the sloped shower floor is right at the glass partition. I used a standard rubber shower pan membrane. Extended approximately 16 inches up 3 walls and the same amount extended outside of the shower floor onto the shared common bathroom floor. On the common bathroom floor, 1/4" tile backer was fastened to the plywood subfloor and carried over to, and stopped, at the 3" deep recessed shower floor which was then built up with a mud pack to flush out with the tile backer. Yes, screws that fastened down the tile backer on the common floor penetrated the shower pan but 2 coats of a liquid rubber over reinforcing mesh ( 24 inches out ) were applied on top of the tile backer. In summary, the 24 inches outside the shower are completely waterproof. Could have gone even more, but felt confidant with the distance. The existing shower floor was retrofitted. Above, in a earlier question, there is a answer to how that was framed.
The joint created where the 1/4" tile backer meets the sloped shower floor was also waterproofed with reinforcing mesh and liquid rubber membrane. 12 inches either side of joint on surface of tile backer and new mud pack / mud set shower floor pan."

When you say the shower floor was recessed 3", does that mean you cut a whole in the existing subfloor and built a new subfloor just under the shower that is 3" lower than the rest of the subfloor in the bathroom? I'm not quite sure how your subfloor under the shower is 3" lower than the rest of the subfloor, especially since I am sure you have joists running underneath it? Possibly this was built on a slab and this design would not be possible with a wood subfloor?

There are many ways to recess the framing of a wood framed home. You need a structural engineer to tell you what to use and how to do it. On this current Vancouver curbless I asked for a 1.5" drop and was told I could have no more than 1 1/4". With the plaster and lath ceiling below we could only get 3/4" drop. It's a start and all I need to build another curbless shower here in Vancouver.

The builder installed the new 8" LVL's (Microlam Beams) to the exsisting 2"x10"'s. These 8" LVL's where cut from a 16" LVL and ripped in half.

These calculations factor in many things. Span tables. Type of wood. Length of joists.... and on and on. Make sure the person designing this knows what there doing.

Here is a look at an LVL sistering.

John Whipple
By Any Design Ltd.
http://www.no-curb.com

John.....great work. I love to see the little things that scream "I'm a builder, who pays attention to the little details with pride...." Things like wiring that are perpendicular to the joist. Metal strapping for drain support in addition to the blocking.....Please tell me that before you put the new deck down, you did vacuum the wood chips and shavings out.......:)

Hi Thomas, I am the same meticulous guy. And I would for sure vacuum the wood chips and shavings out. ☺ I would also add two more metal straps to holt the waste pipe in place because these pipes are not very flexible and will easily crack (especially at the connections) if someone hits the pipe. You wouldn't even notice it but later when you get water stains at your ceiling. Furthermore I would cut the ends of the metalstrips of because of the risk of injury. (See picture below)

One question: The drill holes are big enough for both power lines, so why are running the two power lines not through the same drill wholes? Every drill whole weakens the joists - or not? I realy want to know. Pleas enlighten me.

Regards,

3D-Tile-Design - Bertram Tasch
Maple Ridge, BC (Greater Vancouver)
http://www.3D-Tile-Design.ca
.

This looks like it possibly maybe two different circuits. If you look closely, it looks like one of the wires turns and comes down the joist. I'm not sure why they did it this way. The 3/4" dia. holes don't weaken the joist unacceptably, but I would have allowed a minimum of 6-8" between them and centered them in the middle of the joist just as a practice. This exceeds the spacing rule of no less than 3 x the diameter of the largest hole. I was taught old school. The upper third of the joist is in compression, the lower third is in tension, that leaves the middle third for drilling. If I ever even thought about notching, my mentor would have purposely dropped his framing hammer on my head.

Hello Thomas, I would say there are three wires in the picture. About the holes, I learned exactly the same "stuff" during my apprenticeship as a Skilled Construction Tradesman and again at Master School.

S. Thomas Kutch thanks for your questions and insight. At this point in this renovation I have only help layout out the ground work. The electrical work and framing is all done by other sub trades on the project.

The notch out (recess in floor) was engineered by a structural engineer and all work so far - plumbing, electrical and structure have been inspected and passed by both the structural engineer and city inspectors.

We will be going back to upgrade the subfloor somewhat and start the shower pre-slope process. This will be a large barrier free shower showcasing a nice drain 5"x5" Sioux Chief which I ordered through Noble Company. The shower will have a fixed panel and no door.

As for drilling through framing members those joists are 4"x8" (old 2" stock and new 1 3/4" microlams LVL's) total and no holes are drilled within 2" of the top or bottom.

As for why the electrian drill two holes? Not sure. I do know the work was inspected and past city hall.

Thanks for the comment.

JW