EcoRenovator (
-   Renovations & New Construction (
-   -   AC_Hacker's Mini-Loo... (

AC_Hacker 03-08-12 12:52 PM

AC_Hacker's Mini-Loo...
4 Attachment(s)
{EDIT, 3-23-2012}

I should say at the outset, that this is an unusual project. It has been, by far the most unusual from the standpoint that with only one exception, everyone I know, every friend I have, male or female has not supported this project. 'Not supported' is actually too mild a term, 'strongly opposed' would be much closer to the truth. They all vigorously tried to dissuade me from doing this, they offered me a blizzard of alternatives that they thought were superior. Finally, they gave up and decided that I was too ornery to be reasoned with, and not quite deranged enough to have committed to a mental institution.

However, without exception, now that it is actually built and working, they think it's really great and my strongest critic seems to have forgotten his fierce opposition and has decided to build one, "...just like you did."


* * *

My house doesn't have much floor space, about 700 sq. ft. and it was built before an indoor toilet was considered a necessity for a working class family in 1892.

When I moved in, a true water closet had been installed on the back porch and then the back porch had been enclosed. Bathing was accomplished in another poorly conceived room which reduced the size and usefulness of the kitchen.

My goal was to convert the water closet into a Scandinavian style toilet/washroom/shower combo that would offer full utility and take up the absolute minimum amount of space, and to make the space from the old bathing room available to an enlarged kitchen.

The design was for the mini-loo to be as small as possible, allowing for minimum code dimensions.

Since I was going to use the mini-loo as a shower, everything had to be completely water proof... no guessing here.

Initially I had the idea of using a modern Japanese style flushing squat toilet, and having it's drain also be the drain for the shower. I hunted for several days on the Internet and only found one supplier in the US, and the unit was 1,600 dollars, mighty expensive. I also did some surveys and discovered that American women in general do not seem to take kindly to the idea of a squat toilet, in spite of the studies of health benefits I suggested that they read. Perhaps another time...

The project has been quite a success, although I made some mistakes along the way, which I will describe.

Top pic shows the floor joists with blocking reinforcing to prevent any flexure of the floor or walls. It also shows the RV toilet I initially thought I would use for the project. This toilet was the right price (free) but flushed down through the floor, which I would later realize would be very difficult to make completely water proof... more later.

Since I had the floor open, I took the opportunity to replace all of the cast iron and lead waste lines with new ABS.

The bottom pic was taken after the floor, 3/4" marine ply + 3/4" pressure treated ply were screwed down to within and inch of their lives, with coated screws. I found considerable help from a Canadian Tile-Setters blog, regarding exactly what is required for a very rigid floor, even how to lap and how to fasten, with engineering studies supporting the methods. Also discussed in considerable detail was blocking requirements... very thorough.

The sink (upside down) and the floor drain are shown placed on the floor for consideration of fit. The sink was very small and fully functional. I would later realize that the floor drain should have gone in the very center of the floor, but at this time I was planning on the W/C waste line also going through the floor.

Top pic shows shower stall (AKA: wet room) blocking going in. The total blocking phase took considerable time. I used screws and metal brackets throughout and was glad I did, because it allowed me (with only rudimentary carpenter skills and a complete newbee to tile work) to easily re-do parts that were not quite right. The vertical boards at the bottom are for the support of the water proofing membrane that would be a key part of the water-tight strategy.

By the time this photo was taken, I realized that the RV toilet would not be a good choice, both from a water-proof standpoint, and also from an aesthetic stand point. Shown in the pic is the filled-in hole for the toilet. I used the plugs from the hole saw, and glued them back in with epoxy glue. Not shown is a a plywood block underneath the floor to support the glued-in plugs.

Bottom pic shows a fly's eye view of the mini-loo, with my #12 shoe for an idea of the size. The finished width (after tile) is 32.5 inches and the finished length is 49.5 inches.

At the bottom of the pic is the in-wall flush assembly and toilet hanger that is made by Geberit.

It certainly upped the cost of the mini-loo, but it works great. The Toto toilet I found to go with it looks like a normal toilet, and actually takes up less room than the RV toilet.

The Toto toilet & Geberit in-wall assembly were both designed from the beginning to be dual flush. As I write this, I have used the mini-loo for about 5 months, and have not had a single mis-flush. My old low-flush toilet required the very worst kind of plunging at least once a week. I like this way much, much, much better.

(to be continued)


AC_Hacker 03-14-12 11:44 AM

Mini-Loo Part 2
10 Attachment(s)
The image below shows details of the sub-pan, which will be below the plastic membrane and must have the proper slope (1/4" per foot). I have seen on-line instructional videos that neglect to slope the sub-pan. This will result in bath water that never drains out of the pan, and the festering problems therein.

The beginning of this process is to project the pre-pan slope outward from the part of the three-piece shower drain that fastens to the floor, to the wall. In my case the wall was not even, so I had to make custom-tapered guides for each side that were screwed to the edges of the floor. These guides then became the basis upon which the pre-pan could be properly shaped.

Tar paper was stapled to the floor, and mesh was stapled to the tar paper. The mesh reinforces the pre-pan and the tar paper provides som de-coupling that will allow for differences of shrinkage and expansion between the pre-pan and the floor.

The next step is to pour the pan (I used quick-set cement) and to form the slope around the shower drain, as shown below.

Here, William Hackerson is forming the conical pre-pan slope using a series of pieces of wood for the slope. It was necessary to use four pieces of wood for this process to allow for changing rqadius. This process was the first concrete we had ever mixed up, and the forming went quite smoothly.

We allowed the pre-pan to harden over night before proceeding to the next step...

Here we are installing the plastic pan membrane. There was a PVC material that was available that was quite inexpensive ($27) and tough, but I went on the web and searched out health concerns of PVC and decided that it would be wiser to spend $150 more for a non-PVC membrane than many tens of thousands of dollars later in health care costs. This membrane also requires a special glue to glue it to the shower drain. This membrane is not as tough as PVC, but once it is carefully installed with the sub-pan below and the pan above, it is eternal.

Notice that William Hackerson is not wearing shoes and is sitting on a folded towel pad to protect the membrane as he is working it into place. Cold membranes are not as easy to work with as warm membranes.

We were very careful to make sure NOT to use nails in the floor (over time they can work up and possibly puncture the membrane) and also to check by hand, every part of the floor and slope-guides for any debris or projecting screw head or other hazard to the membrane. After the thorough inspection, we vacuumed the floor very well... only then did we lay out the membrane.

It is suggested to allow at least 6" extra membrane to go up the walls as a capillary safe margin. We built the shower stall with corners that allowed the corner fold to go into spaces in the corner, and keep a smooth wall.

Also very important is to put in NO NAILS through the membrane below the capillary safe margin.

Below is a photo of the drain. There were several important steps that I wasn't able to photograph because I was so involved...

Once the membrane is adjusted and in place, it is very easy to find the drain. The drain hole is cut after the membrane is situated. I used a narrow bladed knife that was quite sharp and used the inside of the drain hole as my guide. The middle ring will be bolted through the membrane to the bottom ring, and there are bolt holes that need to be located for this. I used a rounded swizzle stick to locate the bolt holes and then I used a leather punch to make the holes through the membrane. I have seen photos of professional tile people using a matte knife and cutting an "X" over each bolt hole, but that seemed very un-professional to me. I like my method better.

Also not shown is the application of the special adhesive that bonds and waterproofs the membrane to the bottom ring. The adhesive comes in a caulk-gun tube and is extruded as caulk would be, with the exception that the special adhesive is VERY VISCOUS and comes out very slowly. The tip of the caulk gun is poked under the membrane and above the bottom ring. adhesive is applied around the drain hole, and a continuous bead of adhesive is required. I chose to use a little too much rather than too little.

If you look closely at the photo, you will see, just to clockwise, near the bolt holes, at the edge of the membrane, small grooves through which water that gets past the tile and into the pan, can finally drain away. Make sure that these grooves are not blocked by glue. I took my knife and cut away small bits of membrane above each groove.

Although it was not called for, I thought it would be an improvement to improve the above-membrane porosity by adding two layers of plastic screen (not aluminum... brass would also be ok) above the membrane and below the second drain ring.

In the photo above, the caulk was applied and the second ring was bolted down and then the assembly was left overnight. The the second ring was removed and the screens were added and the second ring was bolted down, this time forever.

As a final step, I came back with a drill bit and had-twisted it to remove any bits of screen from the drain grooves.

I tested my strategy by pouring a quart of water onto the membrane, and the water flowed out, first over the second ring, and lastly through the drain grooves and screen layers under the second ring and very quickly the membrane was completely dry. Proof positive.

* * *

Not photographed was the water test, which consisted of plugging the drain with an expanding drain plug and filling the shower floor to a depth of two inches and letting it stand over night. If the membrane is leaking it will be evident pretty quickly.

If you check it in the morning and there is no leaked water runnin on the floor, or on any surface below, and if the water is at the same depth, only then have you won and is it OK to proceed.

I won!

* * *

Not photographed in the process below was the top ring of the three-ring drain assembly. It has threads and can be screw-adjusted to the anticipated level of the top of the mud bed + thinset + tile thickness. In the photo below, the ring has been put in place and the drain has been taped shut.

In the photo below, the tar paper has been nailed to the walls (NO NAILS BELOW THE CAPILLARY MARGIN) over the membrane margin and down to the top of the sub pan. Then the mud bed is mixed up and applied over the membrane, it is a very stiff sand mix.

The sand mix is not troweled into place, but rather pounded into place because it is so thick. Slope (1/4" per foot) most be observed as well as straightness and level of the edges. The sand mix is not quick set, so there is plenty of time to keep pounding and scraping until the proper shape and slope is achieved.

The general practice is to allow the pan to set over night before proceeding. I discovered an alternate procedure, after the fact, which is to apply the thinset and the tiles to the wet mud bed, then use small boards to check the slope and evenness of the tiles and to tape them via the board to make the floor tiles perfectly sloped and even. I wish I had done it the second way.

So after sitting overnight, it was time for tile, I used flat river stones that were glued to mesh, it was a bit tricky handling the mesh, but it worked out. Best to thinset one panel at a time.

After the thinset set up, on went the grout...

We tried a number of different grouting tools, but for the stones, pushing the grout in with the heel of the hand worked best.

Turns out that there in a 'sweet spot' during the grout drying when it is set up enough to provide strength to the tile (or stones) but is still pretty easy to rub off.

Buffing the stones with a damp cloth reveals the floor...

(to be continued...)

AC_Hacker 03-23-12 01:38 PM

6 Attachment(s)
After the floor was done, the walls became the focus. I decided to put in a couple of niches, one for shower-bottles (shampoo, etc) and one over the sink where a medicine cabinet would normally be.

Tar-paper was chosen to be the water repeller behind the cement board, which was behind the tile. The strategy is that the tar-paper is applied and lapped so that as far as possible, it would be feasible to shower with only the tar-paper as a barrier. The anticipated paths of the water drops are taken into account, both to keep them from going where you don't want them to go, and most importantly, to give them an easy escape where you do want them to go.

This isn't the best of photos, but it does show the progress of the tar-paper and the hole where the plastic niche box goes.

The tar-paper is up on one wall, and the cement board is going in. NOTE: NO NAILS OR SCREWS BELOW THE CAPILLARY MARGIN!

I temporarily fit the Toto into place to check for fit and concept, etc. I did this kind of thing with the components of the job, several times during the construction of the mini-loo. No small part was to keep my spirits up and to keep in mind what the finished job would be like.

Concrete board has gone up on the toilet wall.

The Giberit flush tank and toilet hanger assembly are being buried behind tar-paper and concrete board. The rectangular protrusion through the cement board is where the dual-flush actuators will go. The system is designed so that the flush actuator panel can be removed and replacement parts can be easily installed through the actuator panel opening.

The whole system is completely different from anything I have ever encountered before, but it is very well thought out and works perfectly.

Ledger boards have been nailed to the wall (perfectly leveled and even), about 1 and 3/4 tile spaces above the edge of the floor.

The ledger boards are the 'datum line' upon which the tile setting begins. After the walls are set up, the ledger boards will be removed and the bottom rows will be finished.

I bought a cheap laser leveler tool. It was very helpful and worth the price, but patience and skill are still required.

The first two rows are going in. Small tile-spacers are used to keep spacings even.

This was the very first time that my son William Hackerson, or myself had ever attempted tile. The experience certainly increased my respect for skilled tile-setters. They really earn their pay. It also saved me several thousand dollars and made even possible to contemplate such an unusual custom project.

Considerable progress has been made on the corner.

My son & I has our share of tense moments but the project continued, and so did our understanding and respect for each other.


Daox 04-01-12 09:29 AM

Woo, almost missed this thread. Great job on the work. I love the look. Is it finished now?

AC_Hacker 04-01-12 11:11 AM

1 Attachment(s)

Originally Posted by Daox (Post 21055)
Woo, almost missed this thread. Great job on the work. I love the look. Is it finished now?

I still have more pix to post... The mini-loo is finished to the extent that it is fully functional and has been in full use for the last 6 months, but there are a couple of pieces I need to complete:

Door - My concept is to make a bi-fold door that works similarly to what is used in telephone booths (remember them?) or airline bathrooms. I still have not clarified the proper materials to use or the approach I will take to insure that it is spray-proof. I have tested some mock-ups and I have enough room, but it needs to be spray-proof and also allow for ventilation. What I am now using is a temporary shower curtain on the inside and a hand woven rug for the outside. The shower curtain is working pretty well for stopping spray, but it is not as elegant as I would wish. The rug-door is actually working well and I am tempted to keep the concept, only replace the flat-weave rug with a tribal hand made pile carpet... it would be more classy but I would need to retain the shower curtain which I don't care for so much. Interestingly, women don't seem to take offense at the rug-door as I would have expected.

Lighting - I thought this would be easy, but it is not so simple. There are issues such as color, contrast, placement, direction and spray-proof that I hadn't anticipated. I have tried several different lights but I am not satisfied with any. I first tried a quartz-halide, good color, but much too bright. I then tried a cute LED but the color was 'iffy' and contrast and light distribution was all wrong. I have seen an LED diffused ceiling light, but $50 price is slowing me down. So, for now I just have a rigged up light that is functional but awful. In the pre-renovated WC, I used an occupancy sensing light which was really great. I want that feature too, but have questions about spray.

Another thing that I want to include is a bidet toilet seat similar to this. I have provided a spray-proof GFI for power and have also plumbed in a water outlet for it. I have talked to some folks who have lived in Japan and have used these and they think we, in the US, are living like barbarians.

Interestingly, in Japan, bathrooms are not heated, but toilet seats are... what a concept!

I agonized over the need for heat for heating the mini-loo, bare feet on cold stone floor and all that, but just turning on the shower for a brief time takes care of that problem, too.

Another idea I have been trying out, is not including a vent fan. I purposely mounted the small double hung window very high on the wall, and when the top is open, venting works well due to the chimney effect of the warm air and the tall aspect of the space. The door will need air vents in the bottom for the idea to work. When the mini-loo is dry I close the window. Works good. When the weather here is particularly humid, I've been using a small fan on the floor to speed up drying. I think a properly vented door will take care of this.

Everybody asks about toilet paper getting wet...

I have setteled on using the shower handle (installed in the up-is-off position) as the toilet paper holder. That way you can't turn on the shower without being reminded to relocate the TP.


S-F 04-01-12 11:29 AM

Yeah. Bidets are for sophisticated people. Imagine sticking your hand in a pile of crap and then trying to clean it off with paper. :/

nascenta 04-03-12 09:08 AM

I love what you have done. So space efficient! Thank you for taking the time to document what you did. I think that a good alternative to the cement board is ordinary drywall covered with Kerdi, a tileable waterproof membrane that gets put on with thinset. It can be used on the floor too over the mud bed.

AC_Hacker 04-03-12 12:17 PM


Originally Posted by nascenta (Post 21081)
...a good alternative to the cement board is ordinary drywall covered with Kerdi, a tileable waterproof membrane that gets put on with thinset. It can be used on the floor too over the mud bed...

I looked into the Schluter System (of which Kerdi is part), and all of it's parts.

It makes a lot of sense, is really well engineered, well thought of in the trade, and uses quality materials throughout. My girl friend's shower is Schluter System, and it has been in use over a decade without issue.

However, when I started to add up the Schluter System component prices, I had to re-calibrate using it as a feasible direction for my project. My project resources are quite limited, so I have to consider budget at every step.

I can certainly see why professional tile-setters would prefer it, it is faster and less likely to fail than the traditional approach I chose. Professionals can pass the material costs on to their client... I can't

But you are right... kerdi is great stuff.


All times are GMT -5. The time now is 08:54 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Ad Management by RedTyger