Cement board or green board?


Old 09-10-15, 08:40 AM
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Cement board or green board?

I am redoing a bathroom in my house and want to know if I should use cement board or green board?

A friend of mine who does basement renovations and who just recently bought a still be constructed house says he always uses green board for tub/shower setups. He also mentioned his new house being built uses green board as opposed to cement board.

Is there a right or wrong answer with the decision at hand? What is your thought and opinion?
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Old 09-10-15, 09:29 AM
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Green board is outdated and no longer acceptable. The main reason for greenboard under a tile surround was to negate the expensive of a mud bed. While greenboard is water resistant - it is not waterproof and if it gets wet the tile job will fail! It is ok to tile over drywall in non wet locations.

Many codes used to require greenboard for all the drywall in a bath rm but most no longer do so. Regular drywall paints better than greenboard and primer followed by a coat or two of latex enamel gives the drywall all the moisture resistance it needs.
Old 09-10-15, 10:12 AM
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One of the moisture resistant wall boards is OK for use outside the tub/shower area. In the tub/shower I assume you will be doing tile so I would use cement board, Hardie Backer or some other substrate suitable for thinset and tile. My baths I did with cement board in the tub/showers for the tile and regular sheetrock like MarkSr recommended. The walls were primed and painted and not 12 years in there have been no problems but we are very good about properly ventilating after showers.
Old 09-10-15, 12:54 PM
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Your friend is living in the past. Cement board for any wet area. For the difference in cost don't take a chance.
Old 09-10-15, 02:54 PM
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If associated with a Kerdi membrane in a shower, you can go with green board. In the absense of the membrane, a cement backer board is required along with some form of vapor barrier. That barrier an be products like Redgard or Hydroban which is painted on top of the cement board. Or you can use a 6 mil poly or 15# felt paper shingled up underneath the cement board.

I'm afraid your friend, while probably very adept overall, is lacking in knowledge on best practices as it applies to tile and as currently defined by leading authorities.
Old 09-12-15, 10:56 AM
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Cement board certainly will work great, but it is hard to work with. I find to get really good edges that I have to cut with a circular saw as opposed to scribing and snapping. The last shower that I built, in my own house, I used Denshield. It scribes and snaps like drywall and some of the leftover scraps are still out in my backyard a year later and look brand new. A year of rain and snow didn't seem to affect it at all.

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