# butting backer board up to plastic shower pan



## ponch37300 (Nov 27, 2007)

I just installed a plastic shower pan and am going to be putting densshield on the walls for tile. The plastic pan has a lip on it. I believe I can just run the densshield to the lip and then caulk between the dens and shower pan and the tile will come down to the actual pan? Or do I have to run the densshield over the lip? If I have to do that I will have to shim out the walls probably 1/2" in some spots. Thanks for any help with this and here is a pic.


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## J187 (May 19, 2006)

Hi, your flange should go flush to the walls/furring strips and the CBU should overlap the flange. The CBU should stop 1/8" short of the deck as should the tile. The space will be caulked after tile.


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## ponch37300 (Nov 27, 2007)

Thanks for the reply. So even though the front of the cbu will be waterproofed and the front waterproofed part will over hang the flange I still need to fur the wall out so the whole sheet of backer hangs over the flange? That means alot more work since I was only planning on removing the current drywall where the cbu was going and not all the way to the ceiling so if I fur the walls out the cbu will be sticking out farther than the current drywall.


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## bjbatlanta (Jul 16, 2008)

Yes and you will use a "bullnose" tile around that protruding edge to finish it off....


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## wrangler (Oct 9, 2008)

ponch37300 said:


> Thanks for the reply. So even though the front of the cbu will be waterproofed and the front waterproofed part will over hang the flange I still need to fur the wall out so the whole sheet of backer hangs over the flange? That means alot more work since I was only planning on removing the current drywall where the cbu was going and not all the way to the ceiling so if I fur the walls out the cbu will be sticking out farther than the current drywall.


Furring it out will be quite easy. Just take 1 1/2 - 2" wide strips of drywall and tack them to where the studs are bare. Then attach your CBU to what ever height you had planned. Check to make sure that that edge of your pan is deep enough to allow for the thickness of the furring strip, cbu and tile.


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## ponch37300 (Nov 27, 2007)

bjbatlanta, The pan in the picture is the shower floor. I will use a full tile to start not bullnose. Maybe you thought it was the side of the shower? So are you saying I can butt the densshield up to the lip or do I have to go over the lip with the backer? Thanks for your help


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## bjbatlanta (Jul 16, 2008)

The bullnose is to finish the sides. Your backer needs to go over the lip of the pan, within 1/8" or 1/4" of the lower lip on the pan. Your regular drywall will be attached directly to the studs throughout the bathroom. That will get you TO the top lip of the pan. Add your backer over the drywall. You will need a bullnose to finish the edge. You can "strip" the studs in the actual shower area as wrangler suggested to save buck or two....


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