most guys installing dryer/washer receptacles or even a standard 120v 15a recetacle in a basement first mount a wooden board to a cement wall... is that required by code, or is it legal to install receptacle directly to a concrete wall?

It's not the outlet that is in question, it is the wiring method:
334.12 Uses Not Permitted.
(10) Types NM and NMS. Types NM and NMS cable shall not be used as follows:
d. Where exposed or subject to excessive moisture or dampness

The cement wall *can* be considered to be a "damp" location and be easily tested by taping some plastic to the wall...after a few days moisture may appear on the inside of the plastic.

I don't know about you (or anyone else), but it's a whole lot easier to just slap up a half a 2x4 up on the wall and staple the wire to it than it is to "test" the wall and strap the NM to the cement.

You can attach the receptacle to the wall.

...but not the wire.

The question did not ask about wire but if it did, I would not consider the inside of a concrete basement wall excesively damp under most conditions.

[This message has been edited by Electricmanscott (edited 01-03-2006).]

You guys just run wire down the wall?

We use this stuff called EMT works great. Throw some 10-3 down that bad boy and its done before you even find your 2x4.

[This message has been edited by Trick440 (edited 01-12-2006).]

Using wood is the cheapest way of doing for sure, but I prefer doing it in pipe too. It looks more professional and the NM is w/o a doubt protected from physical damage. I can consider that an important thing to do, especially any receptacle operating at 220 volts in an unfinished basement!

I'm not even sure wood is the cheapest way ... if you buy the wood.