Need help & advice on big project

I'm a newbie to this forum, but you guys seem like a friendly bunch and the advice I've found in existing posts has been very helpful. I'm hoping I can get some advice on a big project I'm starting.

We're doing an addition to our house. We hired out the rough & topout plumbing (all done & passed inspections), but I'd like to try to do the finish work myself. I've done a lot of plumbing work in the past, but it has all been repair & remodel work, so there are a lot of things that are unfamiliar to me in a new construction project.

Depending on how things go here, I may continue this thread with questions about the rest of the project, but for now I'd just like to throw out some questions about my whirlpool installation, since that is the biggest challenge. I would greatly appreciate any comments on the following problems I'm facing:

1) We made a huge mistake right off the bat- We didn't buy our tub until after the architectural design was finished and the plumbing was already roughed in. As a result, we didn't plan for a well placed access panel for the whirlpool tub we wanted. The manufacturer recommends a 1'x2' access at the rear of the tub. Because of the bathroom design, we can't provide access through that wall. The only option is access from the front of the tub. This way you can get to the pump from the side, but it seems like it would be a hassle doing any work under there from that angle. So, how big of a mistake is this? Am I screwed? I'd like to get some feedback before I go any further...

2) The rough plumber left the tub drain pipe sticking up through the slab as one would expect and the concrete guy formed a large hole around it to allow for clearance and re-positioning of the drain- which is fortunate because that's exactly what I need to do. The plumber did a remarkable job of guessing where the drain would be, considering we didn't have any rough-in details for the tub placement yet, but I still need to move it a couple of inches.

What I don't know is- in this type of installation, would the rough plumber already have put a P-trap under the slab, or do I need to install it now as I plumb the tub drain? (I guess I could keep digging to find out for sure...)

If I install it, then it would be easy to use the P-trap to position the drain in the right place. If there's already a trap down there, then I assume I'd just find some sort of offset coupling or a couple of elbows to do the job? I just don't know what standard practice is for this kind of thing. I'd appreciate your advice on the best way to move the drain.

3) The mfg instructions say that our tub (Am.St. 72x36) can be installed on its own feet without mortar, -BUT- it goes on to say that mortar can be added for additional stability. I'm not sure if I should read anything between the lines there. Should I use the mortar, or am I OK without it?

4) The tub is closely surrounded by 3 walls, with only about 3-4" of deck. I'm starting to realize this may be very difficult to lift into the hole when we're ready. The fiberglass tub is surprisingly lightweight but still may be quite difficult to lift into the hole from just one side without hitting any of the tubes or fittings. Any tips, tricks, or advice?

Thanks in advance for any help and comments.

questions

1) We made a huge mistake right off the bat- We didn't buy our tub until after the architectural design was finished and the plumbing was already roughed in. As a result, we didn't plan for a well placed access panel for the whirlpool tub we wanted. The manufacturer recommends a 1'x2' access at the rear of the tub. Because of the bathroom design, we can't provide access through that wall. The only option is access from the front of the tub. This way you can get to the pump from the side, but it seems like it would be a hassle doing any work under there from that angle. So, how big of a mistake is this? Am I screwed? I'd like to get some feedback before I go any further...


1. your second mistake may have been if you have already purchased the tub, because many companies will move the pump to where the access door has to be. And 1' x 2' is usually inadequate for service access.

2) The rough plumber left the tub drain pipe sticking up through the slab as one would expect and the concrete guy formed a large hole around it to allow for clearance and re-positioning of the drain- which is fortunate because that's exactly what I need to do. The plumber did a remarkable job of guessing where the drain would be, considering we didn't have any rough-in details for the tub placement yet, but I still need to move it a couple of inches.

What I don't know is- in this type of installation, would the rough plumber already have put a P-trap under the slab, or do I need to install it now as I plumb the tub drain? (I guess I could keep digging to find out for sure...)

If I install it, then it would be easy to use the P-trap to position the drain in the right place. If there's already a trap down there, then I assume I'd just find some sort of offset coupling or a couple of elbows to do the job? I just don't know what standard practice is for this kind of thing. I'd appreciate your advice on the best way to move the drain.

2. If the pipe is sticking upright, the trap is probably already installed, but I would still remove it and relocate it to the proper position, assuming you cannot use it where it is by offsetting the tub drain and overflow piping, rather than the pipe for the trap to the tee.

3) The mfg instructions say that our tub (Am.St. 72x36) can be installed on its own feet without mortar, -BUT- it goes on to say that mortar can be added for additional stability. I'm not sure if I should read anything between the lines there. Should I use the mortar, or am I OK without it?

I just use the feet when the tub has them.

4) The tub is closely surrounded by 3 walls, with only about 3-4" of deck. I'm starting to realize this may be very difficult to lift into the hole when we're ready. The fiberglass tub is surprisingly lightweight but still may be quite difficult to lift into the hole from just one side without hitting any of the tubes or fittings. Any tips, tricks, or advice?

Remove the front panel. Slide the tub in and connect it, then rebuild the front apron.

As to mortar, it depends on the floor (it must sit perfectly flat AND level on the floor), and the construction of the tub (some have a full support structure, some sit on feet).

Unless the floor is perfectly level and the tub has a flat bottom designed to sit on it, my personal opinion is it's better to set it in something. Then, the thing will feel like a CI tub...very substantial. It doesn't take much deflection before you can feel it. I supposed you could shim the feet to ensure level and no rocking, if required, but you'd have to ensure they stayed in place with the pump and movement over the years. A mortar bed won't move...

The better the tub, the more substantial its construction (usually anyways). Flex can cause fratures long-term through fatigue. Supporting the bottom well should prevent that. The better the tub, the less flex there would be.