# How-to build a tub surround?



## don_the_amateur (Nov 21, 2005)

I am having a new tub installed but need to first build an elevated area around it.

Since there will be water around it what material should I use?

There will be tile on top of it so could I just use plywood or what building material should I use for the surface and walls?


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## HandyMac (Nov 22, 2005)

Treated ply topped with backer board---the cement/fiber substrate material----will withstand the water best---if any gets past the tile---which should be sealed, BTW.

The walls should be backer board. Then tile/whatever.


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## crapbathroom (Mar 28, 2007)

backerboard is NOT the best, cement is porus remember! you have to seal it before you put your tile on it, we are using a product called denseshield which is wonderful, it's very much like drywall and so it's easy to handle and cut, but it withstands water much better than cement backerboard.


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## asbestos (Apr 9, 2007)

I would have to go with one of the cementious products. There job is not to be waterproof, but to not break down if they do become damp. A water proof membrane can, and should be added for 100% water proofing in areas subject to water.


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## TileGuy (Apr 11, 2007)

crapbathroom said:


> backerboard is NOT the best, cement is porus remember! you have to seal it before you put your tile on it, we are using a product called denseshield which is wonderful, it's very much like drywall and so it's easy to handle and cut, but it withstands water much better than cement backerboard.



Dense Shield is about the most unsafe CBU to use. 1/4 or 1/2 inch Hardie Backer or Durock is the way to go, water proof it for good measure. 
Dense Shield, made like drywall, falls apart like drywall if it gets wet, and it will eventually get wet. Dense Shield is the "new" green board.


Sorry but cement boad is 100% the way to go and waterproofing is always a good idea no matter what. Dense Shield has a major rep for failures. When you nail or screw Densield you cant sink the head, you cant have tears of any size and the best part is having to skim coat over the nail heads with "cement". Any water behind the membrane will cause it to fall apart.... did they say use cement to cover the nail holes? Cement is pourous right? 

I dont mean to be harsh but saying it will withstand water issues better then cement type backer boards is 100% not true. Its quite the opposite.


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## Daryl in Nanoose (Apr 11, 2007)

TileGuy said:


> Dense Shield is about the most unsafe CBU to use. 1/4 or 1/2 inch Hardie Backer or Durock is the way to go, water proof it for good measure.
> Dense Shield, made like drywall, falls apart like drywall if it gets wet, and it will eventually get wet. Dense Shield is the "new" green board.
> 
> 
> ...



I would have to agree 100%, I have torn apart showers with this stuff and it's really not the way to go.


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## rohde_d (Aug 14, 2008)

_Sorry but cement boad is 100% the way to go and waterproofing is always a good idea no matter what. Dense Shield has a major rep for failures. When you nail or screw Densield you cant sink the head, you cant have tears of any size and the best part is having to skim coat over the nail heads with "cement". Any water behind the membrane will cause it to fall apart.... did they say use cement to cover the nail holes? Cement is pourous right? _


Can you tell me what you are using to waterproof the cement board? I am installing walk in shower in my house and it has green board on the walls now. I am assuming I can put the cement board on top of this, seal it and them put the tile over that?


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## KirkG (Nov 16, 2010)

I am having a hard time understanding the comments made here.  I have put a piece of Denshield in a glass of water and it never got mushy or fell apart.  I am not a fan of covering the seams or nails with silicone or thinset, so I use Kerdi Band, KerdiFix mostly to insure nothing gets behind.

You can now use Kerdi Board for the platform, or plywood, covered with drywall and then apply Kerdi membrane.  You can also cover the plywood with cement board, set in thinset and then Kerdi membrane.  

There are many ways to do this job properly.


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## granite-girl (Nov 16, 2010)

I know the kerdi products work well & waterproofing everything before tile is a must


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## nealtw (Nov 26, 2010)

Build stud walls out of 2x6 with top and bottom plates cover the top and front with 5/8plywood, use the kirdi. don't forget the fiberglass under the tub, keeps water warm


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## Jaz (Dec 30, 2010)

I know this thread is old but there's so much conflicting info that I had to comment.  

I believe the best method of waterproofing, especially when building a shower, is with the Kerdi Membrane and Drain system.  Dens will work in some applications, but their shower stall installation instructions do not work.  There's many ways to install tiles properly, so no point in going into that now.

Another error I noticed above is the suggestion to use pressure treated lumber or plywood.  PT should not be used indoors.

Jaz


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## JohnFRWhipple (Oct 22, 2011)

Hey Jaz.  I believe the thread is referencing building a tub surround not a shower.

Building a tub surround is an easy process made more difficult with the use of Kerdi in my opinion except for us tile men.  Here in Vancouver I waterproof showers, tub surrounds and stand alone baths every week.

Denshield is fine for a tub surround but you need to insure the screw heads, seams and most importantly the bottom connection get covered with something waterproof.

Liquid membranes like those made from Mapei, Custom, Wedi and Laticrete work very well and are far easier to instal than Kerdi.

An average pail of liquid membrane will give you 60 square feet of coverage with two coats.  An average tub surround measure 55 square feet of coverage needed.

We purchase our liquid membrane for about $70.00 and this little investment (plus a paint brush) can make an ordinary build stand the test of time.

Jaz Man is a huge Kerdi fan and Kerdi can do an exceptional job at waterproofing a tub but it limits your choice in setting material to non-modified thin-sets.  These preform poorly compared to modified thin-sets but if your looking for "Cheap" setting materials your good to go.

We find that most tile companies require modified thin-sets.  If you like the idea of a sheet membrane then working with a product like Noble Seal TS is the way to go.  With Noble Seal TS you get sheet membrane science and the full spectrum of thin-sets to work with.


In Vancouver we like to board with Cement Board, Hardie Board or Green E-Board.  I never hang Denshield, regular moisture resistant drywall or drywall in any shower project or tub surround setting.  That said many builders still love it.


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## joecaption (Nov 3, 2011)

I've been in the building business over 30 years and have yet to see anyone use treated plywood inside of a home. In fact it's againt building code in the US.
Just screw up 1/4 tile board on the walls, tape the seams with fiber tape and set it with thin set, seal it with Red guard then tile set in thin set. Seal the grout when you done. Now your water proof.
The only time I've seen a 2 X 6 wall in a bathroom is in the "water wall" the one with all the plumbng run inside of it. To allow room for the 3 or 4" vent pipe.
I've never seen plywood used behind any tile board in a tub or shower area. It would make the tile stick out over the sealing lip to far on the tub.


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