bath finishing

Sheetrock

After the framing, ductwork, plumbing, wiring, and rough inspections were complete, we could start the sheetrock and cement board in the shower. The walls in the bath common with other interior house walls would get 2 layers of ½" laminated together. This would attenuate noise.

Paul Gee and Weed (Peter Rebovich) helped me putting up the rock on different days. After the first layer was up, I caulked the perimeter between the edge and the wall to help eliminate any passageway for noise to travel through. The 2^nd layer was laminated to the first with joint compound applied with a notched trowel. The seams and edged were taped normally. As an experiment, I skim coated the walls with a thin coat of spackel. This would give a more plaster like texture to the wall. It came out ok but I’m not sure if the extra work was worth it. It was a lot more sanding.

. Paul Gee

I used an alkyd paint. I haven’t had much good luck with water based paint in bathrooms so I felt that it was worth the work up front to do it right. Even with the exhaust fan on, the whole house smelled like solvent. It gradually dissipated over a few days until it wasn't too bad.

The fixtures went in pretty easy and the only thing still left is the door and window trim. It can wait.

Tile Preparation

This is the largest and most important part of the job. Contractors will tell you that they recommend setting tile directly on plywood. I have always felt that this is a poor way to do the job. My feelings about this came from when I was working as a handyman in college. I repaired many relatively young tile floors with tile set on plywood where the tile was just too loose. On the other hand, older installations set in mud (cement) had to be jackhammered out. Even then the tile did not come off the base, it stayed attached to the chunks of cement. I do agree that mud installations are costly, but cement backer board (CBU, i.e. Wonderboard or Durock) is a good compromise. I tried to convince a contractor doing a tile floor in my parent’s kitchen of this a few years ago. His was not interested in my opinion. His position was that he guarantees his work and he has been installing tile floors this way for 10 years and has never had a failure. I was installing a tile floor in my previous house at the same time. We will see the durability of each floor in years to come. I wonder what he will say about his guarantee in 10 years.

As an engineer, I felt at a loss because I could not document my position in this matter other than it being my personal opinion. I started researching in the Internet and found some tile installation advice sites and also the Ceramic Tile Institute (CTI). I wound up buying the CTI manual. It was a hard cover text book that cost about $90 or so. It contained lots if information covering all facets of the subject- commercial, residential, tools, methods, tile grading, specifications, and a whole section called field reports which addressed specific applications. As far as their position on tile installation over wood, they do not recommend it in wet applications. They call it "a high risk for failure installation" This is because if water gets down to the plywood through cracked grout and gets wet, it will expand while the thinset and tile will not. This will break the bond. If the tile is set on mud, it doesn’t matter because the mud will not be affected by it. What is a wet application? They left some wiggle room here. A shower certainly is. What about a kitchen, bathroom, or foyer ? They are not normally wet, but it is not unheard of to have a dishwasher or toilet overflow. Melting snow from shoes in a foyer is probably more common. These are all places where contractors have been installing tile over wood for years. Some jobs are still there, while others have already been replaced. It’s the short sited view of contractors today. They know that the builders warranty for a new house is only 1 year. Does that mean that a "good" installation should last 5 years ? The tile in the bathroom in my parents house (where I grew up) is going on 60 years. I’m not saying that the bathroom doesn’t need remodeling, but the floor and wall tile is still solid. I have repaired the shower wall tile a few times over the years. In hindsight, it probably started to deteriorate and was not re-grouted in time. Even so, it was strong for at least 40 years.

Back to my foyer bath. I used Wonderboard. For the framing, they recommend the maximum deflection to be no more than 1/360 of the span. Previously the foyer floor was framed with 2X8". I doubled these up. The span was 12 feet from the outer wall to the new mantle sill. The 3x5" sheets need to be screwed or nailed to at least 1 inch of plywood. I used 2 layers, the first was 5/8", and the 2^nd was 3/8". The sheets were laminated down with thinset, the same as the tile. Galvanized screws were placed every 4" on the edges, and 6" in the middle. That is a lot of screws. I always forget how much work this stage is, but I know how important. The joints are taped with special fiberglass mesh tape, and applied with thinset. I filled the perimeter where the board meets the wall with caulk. This will allow for some movement in the walls without affecting the floor.

The shower prep was a little different. For the shower floor, poured my own mud pan. I could have bought one, but it would have been $300 to $400 for a good one and I would have been constrained to the stock sizes. Here is what had to be done:

Using thinset, slope the floor under the pan into the 2 level floor drain. I used a bubble level with pitch markings to get between ¼" and 1/8" from the edges to the center.

Install the 40 mil PVC pan liner. This would direct any water that penetrated the tile grout layer into the lower drain entry. The edges would be trimmed and sealed with special cement. This was a check item for the rough plumbing inspection.

Prepare the steel reinforcing. The CTI manual recommended a 3"x3" mesh. I couldn’t find any of this, but my neighbor had some 6"x6" steel mesh in his side yard left over from his construction project. I slipped over there with my bolt cutters and clipped off a piece-neighborly. Carl later offered me the whole roll.

Prepare the screed boards. To help me float the surface with the correct pitch, I cut ¾" pieces to fit radialy out from the drain in the north, south, east, and west orientation. I trimmed the height so they would have a pitch of at least ¼" per foot in toward the drain. The top of these screed boards would be the same height as the finished pan, less the tile.

Pour the cement. The ratio of portland to sand was 1:3. Instead of water I used latex grout additive. It has to be mixed very dry. I filled the pan to the height of the screed boards and packed down the cement. I then floated the surface as even as I could and checked again with the bubble level. I removed the screed boards and filled in the gaps.

After curing for about 4 hours, the cement was stiff and I re-floated the surface. It is easier when the cement is dryer.

For the walls, the wonderboard was screwed directly to the studs, taped and cemented the same as the floor.

Then the shower floor tile was laid. We had selected a 2"x2" gray and white checkerboard pattern. It came attached to 1 foot square thin mesh which could be glued directly down. Prepared the tile by laying the squares in the pan and removing the border tiles that needed to be trimmed. I then took them out in order. The thinset was mixed and applied to the pan with a notched trowel. The tile squares were then laid in. Using a tile nipper I trimmed the edge tiles and drain perimeter and set them in. At that point I noticed that there were 2 pattern violations, 3 white tiles and 3 gray tiles next to each other. They came from the factory like this. To fix this, I cut the tile off the mesh already in place with a razor knife. It made kind of a mess and disturbed the adjacent tiles. After fixing the gray problem, I decided to leave the white problem to stay. The gray was more noticeable any way.

To prepare for setting the wall tiles, I drew the centerline up each wall. This helped me plan where the grout lines would fall, and how they would intersect with the ceiling lines.

I started setting tiles from the center of each wall to the edge in quadrants. Using mastic applied with a notched trowel, I completed each quadrant. The edge tiles had to be cut. In the past I have used my own score cutter, but this time I had a professional wet tile saw that I bought used from a pawn shop in Phoenix. I had a helper (Scott) do the cuttings. It took a whole day for the two of us to set all the shower tile.

After waiting 2 days, I did the grouting. My mistake was that I mixed too much grout at once. It takes a while to work into the gaps then it has to be sponged off the tile faces before it hardens. Since I mixed too much, it got too hard before I started sponging making it really difficult to get off. To make matters worse, I had blisters starting on my palms from the grout float. I survived it.

The floor tile I approached the same way, from the centerlines out to the edged in quadrants. I used 3/16" spacers to keep the gaps even. After setting a few rows, I settled the tiles down using a 1"x2"x16" beater board laid across the tiles and tapping with a rubber mallet. Grouting was easier this time. I filled the perimeter with caulk and set the ceramic baseboard tile to match the floor.