I installed a new tub faucet because the old one had a terrible diverter.

Because the pipe moves in and out (about 1.5inches), it’s impossible to get the new faucet to fit tight against the tub. I also can’t caulk any gap because the movement will break the seal.

I have a plan to fix it and I want to make sure this is the best plan.

I’ve opened up the wall to strap down the pipe.

This is what it looks like inside:

enter image description here

The pipes run along the inside of the studs so I cannot screw in a strap.

So here’s my plan and I’d love feedback. I plan to add a 3/4” thick piece of scrap plywood behind the pipe. 3/4” is the distance between the tub and pipes.

Then, I’ll strap the pipe to this scrap plywood with this:

enter image description here

That will keep the pipe from pulling towards the inside of the tub.

Then, I’ll toenail a 2x4 between the studs. Finally, I’ll screw through the 2x4 into the 3/4” plywood.

Is this over-complicating things?

  • 1
    I do not see a need to "screw through the 2x4 into the 3/4” plywood." If the "3/4” thick piece of scrap plywood" is strapped to the pipe and the the 2x4 is screwed in place then nothing should move. Might as well caulk around the pipe while you are in the back side. Keep in mind you may have to disassemble this if you ever need to access the pipe for repairs.
    – Alaska Man
    Feb 11, 2020 at 23:42
  • @Alaska Man "Keep in mind you may have to disassemble this if you ever need to access the pipe for repairs". Excellent point! That's why I always try to use screws instead of nailing.
    – HoneyDo
    Feb 12, 2020 at 0:13

3 Answers 3


No, I don't think you're over-complicating it. You don't want to just have a piece of 3/4 inch plywood floating around in there without securing it to the studs. There are a number of ways to do this type of job and your approach seems sound. Be sure to securely attach the 2x (screws or nails) and the 3/4 ply to the 2x. Also, I noticed what appears to be moisture around the lower run of copper where it goes through the wall. I'm assuming that is the feed for your tub faucet. I'm further assuming that the moisture is from prior unsuccessful attempts to seal around the tub faucet and isn't a leak. If that's the case make sure you allow that to dry out thoroughly before you seal up the wall. Might want to use a hair dryer on it but remember the moisture is permeating the entire width of the drywall - don't just get it surface dry. Even with a hair dryer I'd leave it open for a day or two. Good luck.

  • It looks like moisture but it’s dry to the touch. The shower hasn’t been used for 24 hours and it’s the same shade of grey. Feb 12, 2020 at 0:03
  • As long as it's dry.
    – HoneyDo
    Feb 12, 2020 at 0:07

I believe that is a coating sprayed on to keep water from penetrating into layers of shower. Middle of those showers is cardboard with fiberglass sprayed over it. As far as the strapping of the valve. Just silicone your plywood to shower use short enough screws as to not hit the tub and maybe use 2 straps instead of just one. I've done it many times over the years when customer does not want to open up wall behind tub or it isn't an option or tile shower other side just slip a piece in through hole for valve with some silicone on it stick it to back side of tub/shower then tighten the trim up against that piece and we do that with no strapping. It has worked for me for over 10 years. Personally I think the 2x4 is not necessary. Seems a little overkill to me but won't hurt anything as long as 2x4 fits flush with the studs without putting stress on the plastic lines supplying valve.

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Feb 12, 2020 at 17:34

A 2x4 toe-nailed and perforated strapping.

Attach two long strips to the bottom of the 2x4 and feed them up between the pipes and the backerboard as you insert it.

Pull the strips taunt. Then take 3" screws and set the tip of the screw (at a severe angle into the face of the 2x4) so that it will pull the strap tight before it bottoms out. If it bottoms out, set the screw even lower or use one of the next holes up.

  • Be careful when one end of a perforated strap isn't secured yet. When the screw bottoms out it will spin the strip and cut you. Keep your foot or a gloved hand on the other end.
    – Mazura
    Feb 13, 2020 at 2:58
  • People think the DiY world revolves around duct tape. Actually it's perforated strapping.
    – Mazura
    Feb 13, 2020 at 3:01

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