Laundry Room Upgrade - Part 2

After finishing up the drywall with four coats of drywall compound, I was ready to paint.  I started with a coat on all of the new drywall and any area that was patched.  The walls that were previously covered in wallpaper already had a good coat of primer so I left those alone.  There were a few brown spots on the ceiling where there were previously cabinets, so I primed those to cut down on the number of finish coats I'd need.  You can see one of the brown spots above my head in the picture below.

The floor was the next thing to tackle.  We'll be putting in a 13" porcelain tiles, so I need a strong, flat sub-floor to support the tile.  The original floor was : 3/4" tongue and groove planking (original), 1/2" particle board, two sheets of 1/4" plywood.  All fastened together with a bazillion nails.  I tried just ripping up the plywood and particle board, but it was coming up in fist size pieces due to all the nails.

After giving up on the 'easy' way of ripping out just the plywood, I pulled out my circular saw and sawzall and got to work.  First I used the circular saw (and a cheap blade) to cut through the floor adjacent to each stud.  Then, a large prybar and sledgehammer to pull the floor up far enough from the joist to cut the nails securing it to the joist.  A couple of hours, sweat and blood and I was able to get the floor removed and piled up outside the door.

Here is the naked floor.  A quick check with string showed me that it was bowed up to 1/2" in the middle.  I didn't want to impede on the floor space in the crawl below, so I decided to sister the 2x8 joists with some 2x6s in order to even out the floor.  With a string line stretched across the top of the existing joists to help line them up, I added a 2x6 to each of the original joists with construction adhesive and screws.  I had to notch the bottom of a couple of the 2x6s to clear wiring in the original joists.

After I finished flattening the floor, I put down two layers of 5/8" tongue and groove plywood for the subfloor - the first was glued and screwed to the joists, the second only screwed to the first layer.  On top of that I attached 3/8 fiberock with mortar and rink shanked nails.  Now the floor is ready for tile.