Holey HardieBacker, Batman!

[Sarah Marie]

Thank you for this board! It helped us complete a successful tile backsplash in the kitchen last winter but we're presently stuck.

We are redoing a shower. We tore out the old tile and shower base, replaced insulation on the external wall, put up plastic sheeting, and installed a new 32x32 acrylic shower base.

Unfortunately, today we installed two sheets of CBU over the flange on the shower base, meaning the surface is no longer plumb for tiling. (This was per manufacturer's instructions on the base! I'm just glad we realized the problem before getting any further.)

We will be removing and installing it properly, but: do we have to get new sheets of Hardie or can we re-install the same boards, driving the screws through the old holes? I'm guessing we have to buy new, but wanted to ask.

Thanks,

[gueuzeman]

Until someone qualified comes along to answer your question..........

[Dave Taylor]

I see Gueuze is up early :---)

Welcome to the forum.

If your used Hardi is not cracked or otherwise broken..... I would be inclined to use it again.... even if I had to place fasteners in different 'Hardi holes', ha ha.

I would be more concerned with the condition of the "plastic sheeting" you have between the Hardi and wall framing studs. Make sure it is intact and that it drapes slightly over the lip of your acrylic shower base.

Other than that.... Just fill any additional 'Hardi holes' you may have with thinset as you tile.....

Or…. forgo the plastic sheeting behind the Hardi altogether, fill additional 'Hardi holes' (if any) with thinset and apply a surface waterproof membrane like RedGard.

Hope this helps bat girl.... er…. I mean Sarah :--)

[Edthedawg]

Welcome, Sarah

Consider this a strong second to abandoning the plastic sheeting, using sistered studs to full-fur the framing plumb and square, then copious amounts of thinset and alkali-resistant mesh tape, followed by liberal coatings of RedGard.

and of course, no pre-mixed masticky foulness in your nice shower

[gueuzeman]

[Sarah Marie]

You guys are great! I'm glad the Hardi can be reused. Thanks for the advice and helpful photos---

I'm attaching the unhelpful picture that came with the shower base installation instructions. I should have been suspicious after seeing it included use of greenboard.

It looks like the next steps are to pull down the plastic sheeting, take care of the studs, and pick up some RedGard.

We went to get mortar a few days ago at [insert big box home improvement store here], had a very helpful type hand me a tub of mastic and cheerfully exclaim it was just the thing for tiling the shower. Thanks to this board, we knew better and left with a couple bags of thinset, instead.

[Houston Remodeler]

WOOO HOOO GO Sarah !

Keep us posted on your progress please.

[gueuzeman]

Gee, and I thought my pictures were humorous. Sarah, you win!

.

[Edthedawg]

awesome job, Sarah. Hopefully you grabbed something like Versabond.

remember to get the alkali-resistant mesh tape for the seams and corners. you wanna make a monolithic structure, on top of which you'll apply 2 or 3 coats of RedGard. it's a good idea to coat part of a scrap at the same time, so you can evaluate your total thickness buildup as you go. You want close to .050" thickness. if you don't have a caliper or feeler gages you trust, spend a few bucks on a cheapy at the store.

[Sarah Marie]

I look forward to posting a good After photo! Thank you for all the encouragement.

Ed, we bought white Flexbond because the plan includes a band of mosaic glass tile at eye level to break up the white subway tile. Was that the right choice?

All good to go on the alkali-resistant tape! We found it in the sheetrock supply area---it was a "new product" to the mastic man, who had never seen it before. Do the interior corners get a three-layer (center-side-side) treatment?

[Edthedawg]

yeah slather it onto the joints and corners the heaviest. It doesn't seem to mind setting up, just takes longer when it's on heavy. make sure it dries well - plan on 3-4 hrs between apps.

[Sarah Marie]

. . . several steps back!

This isn't a tile-specific question, but I can tell that a lot of shower doors have been installed around here and hope someone can put me on the right track.

While prepping the studs for attaching CBU last weekend, we realized there were no studs in position to anchor the shower door. This may explain the water damage.

A pivot door will be installed (this one), with the stationary panel on the left side.

We sistered a stud on the left side to anchor the frame---do we need to do so on the right where the door opens?

The closest stud on the right side is against the door framing, about four inches away. There is plumbing just to the left of where a supporting stud would go, so space is tight. Would blocking be a solution?

Or am I being over-cautious and plastic anchors through the CBU are enough? The shower door instructions don't say anything about studs, but instructions have done me wrong in the past!

[bbcamp]

Sara, if the walls are open, there's no reason not to add blocking anywhere something might be installed, including grab bars (think "future proofing").

[Sarah Marie]

Thanks, Bob!

We do have blocking in other parts of the shower, but I guess the question is: do all of the shower door side jamb screws have to be anchored in a stud or blocking?

The plumbing prevents any blocking below 55 inches on the right side.

Can I do a partial stud up to that point and top it off with blocking, like a T shape?

[bbcamp]

Sure!