I have exposed 2x4 in shower. new homeowner need advise

[jbrian420]

I just bought a house built in 2009. My OCD wife noticed this problem in the master shower. Under the seat is exposed pressure treated 2x4s and there's a gap where the wall tiles don't go all the way up. Subsequently we have a mold issue.

Please answer if this is normal and okay. My wife doesn't like it unfinished.

I was thinking I would cover the bottom side with cement board.

[pushkins]

The answer is No, No and No, there should NEVER be exposed wood of any kind in a tiled shower construction. As you can see via the existing mold, even wood under a seat will start to rot.
This area should have been covered with cement backer board and tiled at the same time as the rest of the shower. Cement backer board cannot be left exposed either, it does absorb moisture it's saving grace is that it doesn't fall apart when it gets wet, nor will mold grow on it, however left exposed it will degrade over time with direct exposure to moisture.

[jbrian420]

The answer is No, No and No, there should NEVER be exposed wood of any kind in a tiled shower construction. As you can see via the existing mold, even wood under a seat will start to rot.
This area should have been covered with cement backer board and tiled at the same time as the rest of the shower. Cement backer board cannot be left exposed either, it does absorb moisture it's saving grace is that it doesn't fall apart when it gets wet, nor will mold grow on it, however left exposed it will degrade over time with direct exposure to moisture.

Thank you for the response. I figured this just was looking for confirmation. I got it tiled and set Sunday. I would say it turned out good for being my first tile job and considering it was upside down in a tight spot that can't be seen.