I'm installing a 72x36 drop-in whirlpool in a corner (at a 45 deg) against two outside walls of my two story ranch house (on slab!). I believe I've got an approach figured out, but I'd like to post my plan and get some feedback (no laughing please, I'm an engineer). I should mention that the tub is acrylic and requires a motor base, but also has level feet. I've got access to the motor and, I hope, drain areas through a panel on the outside wall.
1. Build up a square "dam" out of PT to contain the mortar with holes cut for the feet on the tub.
2. Dry fit the tub into the surround area with the PT dam in place. Use a plumb bob to mark the tub outline on the slab. Dry fit and glue up the waste. Use construction adhesive to bond the PT dam to the concrete floor. At this point I can guarantee being able to drop the tub in place and align with the waste line.
3. I've got a very large hole in a thick slab (>12" deep) so I'm going to fill this up to a certain level with sand and concrete in the rest, but leave "wiggle room" for the drain. I'll drill and insert rebar into the sides of the hole to get some bond between the slab and patch.
4. Plywood, mortar, Kerdi and tile. Plumbing rough-in will have been previously completed for the hot and cold lines.
5. Verify the final level of the tile and adjust the tub feet as necessary
6. Find four close friends for the tub install operation. One small friend (or wife) to get under the surround and guide the tub as it is lowered, the other three friends to help lower the tub.
7. Mix lightweight mortar/concrete to a suitable consistency and fill the PT wood dam to an appropriate level. Using straps lower the tub in place as small friend #1 ensures that the waste and drain line up and that the feet enter the cutout in the PT wood dam
8. Fill tub 1/3 to 1/2 with water in order to force it into the cement and cause the metal feet to settle on the concrete.
9. Finish connecting the plumbing and DONE.
I know this seems complicated, but I don't believe I have enough room under the surround to do the plubming after the fact and I'd never be able to repair the large hole (most of which was dug and left open for the original tub install).
Any better ideas would really be appreciated.
Rick
1. Build up a square "dam" out of PT to contain the mortar with holes cut for the feet on the tub.
2. Dry fit the tub into the surround area with the PT dam in place. Use a plumb bob to mark the tub outline on the slab. Dry fit and glue up the waste. Use construction adhesive to bond the PT dam to the concrete floor. At this point I can guarantee being able to drop the tub in place and align with the waste line.
3. I've got a very large hole in a thick slab (>12" deep) so I'm going to fill this up to a certain level with sand and concrete in the rest, but leave "wiggle room" for the drain. I'll drill and insert rebar into the sides of the hole to get some bond between the slab and patch.
4. Plywood, mortar, Kerdi and tile. Plumbing rough-in will have been previously completed for the hot and cold lines.
5. Verify the final level of the tile and adjust the tub feet as necessary
6. Find four close friends for the tub install operation. One small friend (or wife) to get under the surround and guide the tub as it is lowered, the other three friends to help lower the tub.
7. Mix lightweight mortar/concrete to a suitable consistency and fill the PT wood dam to an appropriate level. Using straps lower the tub in place as small friend #1 ensures that the waste and drain line up and that the feet enter the cutout in the PT wood dam
8. Fill tub 1/3 to 1/2 with water in order to force it into the cement and cause the metal feet to settle on the concrete.
9. Finish connecting the plumbing and DONE.
I know this seems complicated, but I don't believe I have enough room under the surround to do the plubming after the fact and I'd never be able to repair the large hole (most of which was dug and left open for the original tub install).
Any better ideas would really be appreciated.
Rick