How to Waterproof a Shower Bench Using Wedi (Step-by-Step)

Here's the question: what's a good way to waterproof a shower bench made from 2x4s? Today we share how to use Wedi to completely waterproof a bench and it's super easy.

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The first step is to dry fit a Wedi building panel over the curb. Cut a notch out of the Wedi panel such that it will fit down over the Lean curb.

Clean the rabbet cut in the Wedi Fundo Primo shower pan and ensure there's no debris or thin-set in it. Then apply a generous bead of Wedi Joint Sealant in the rabbet and over the Lean curb where it meets the shower bench.

Mark the stud locations on the bench top. And embed the Wedi building panel into the rabbet and Wedi Joint Sealant.

Start the first screws/washers for the panel about 4 inches above the shower pan. Then add screws every 8 inches after that along the stud.

Cut Wedi panels flush with the bench top using a utility knife. Then smooth out Wedi Joint Sealant that oozed between the panel and shower pan. Finish adding all the screws and washers to the vertical panels.

Dry fit the Wedi panel that will be the bench top. Cut a notch in this panel so it fits flush with the stud wall.

Dampen the wood bench top with a sponge. Apply thin-set to the top of the shower bench and bottom of the Wedi panel. Use directional troweling such that all the ridges face the same direction.

Set the Wedi bench top and check that it slopes toward the shower yet is level moving left to right.

Seal the edges and screws/washers with Wedi Joint Sealant to completely waterproof the shower bench.

If you missed our last video, it shows how to frame or construct a shower bench and could be very helpful

[openhand]

Wedi instructional vids recommend not contaminating edges that have to be sealed with their caulk with thin-set. Also to apply caulk before joining panels for full coverage at joint. Do you think the cap panel on that bench will be a problem?

[mattwagoner]

I'm doing the same thing but using Schluter-Kerdi Board. Will the Kerdi Board hold up if you thinset it to the bench top? Seems like it would get crushed.

[chowsman]

Do you have a video on the tiling of this bench?

[AnimalExplorer]

I thought it was imperative that the blue notches were to be exposed so that the joint compound (Wedi glue sealer) is to make contact to the compressed blue foam sandwiched centers of the Wedi board? There are several instances where you do not create the 1/2" notches(Example 1 starts at: 1:27), but directly glue onto the curb where only the black surface is exposed and only the wall panels foam edge will make contact with the glue.

[eoTX]

Thanks for the great instructional videos! I see you're using what looks like Rockwool insulation - should a polymeric vapor barrier be placed between the Wedi and the insulation if on an exterior wall?

[wisconsinwoodsman]

When you tile, will you grout the top joint where the top of bench meets the front "leg" area, or treat it as a 90 degree, change of plane and caulk it?

[Ruso_Moose]

Can you apply anything to the top of the plywood (besides thinset) incase water gets under the Wedi? I've seen some people use 40 mil pan liner, but not sure how they got thinset to adhere to the pan liner when putting cement board ontop?

[BradZaccone]

How is th
e sho
we
r door
going to close with the seat framed on the curb.The door won't slide to the wall

[StarGazer_]

Is Wedi similar to Densshield? It looks like it, and I install Densshield in the same way, but using bath silicone for all joints, except of screws.

[jew-sa]

will this style bench work if I don't have a back wall to mount the back of the bench to, just a side wall? Or will it be wobbly due to no back wall support?

[ryansmith]

Whats the adhesive you are using ?? And whats the board ?

[sweetsilage]

Where did it leak and do you know why?

[quillpigz]

Was this 22" from shower floor or from slab?

[msmales]

Do you guys prefer to use Wedi or Kerdi-board/Schluter products? Also, I believe you guys are in the Pgh area, right? I tend to only find a good assortment of schluter products at Lowes at the Waterfront. Where do you tend to buy your Wedi and Schluter goods? Thanks!

[creedbarnett]

Nice! Would you still use wood framing with a slab on grade foundation?

[networkguy]

what is the height of that shower bench? is there a standard height?

[christopherd]

Nice video. I’m doing the same exact bench in my bathroom, but I’m using Durock. Do you think that I should screw it down to the plywood or do what you did and just thinset the top?

[bennyferranti]

Can you use metal studs inside the bathroom

[isaiassanchez]

i watched the hydro block install page and they recommended 12 in from bottom of pan not 4in

[jgalibois]

There aren't supposed to be any screws in a vertical surface within 12" of the floor. The insertion of a vertical panel into the groove along the edge of the base is supposed to be sufficient to hold the lowest, foot-long portion of the vertical/wall panel against its backing.

Also, a groove along the top of the the end of the curb should have been cut before the curb was installed. This groove would accept the vertical panel on the front of the bench in the same way that the groove along the edge of the base does. That's the proper way to create a seam where horizontal & vertical surfaces meet.

With that in mind, there's no way now to correctly attach the 1/2-inch board that was used on the top of the bench to the vertical board(s) that will be used on the adjoining walls behind and beside the bench. Using 1-inch board as a bench top would have allowed the cutting of grooves along the edges so that proper seams could be fashioned.