I have a deck that is within 12" of the ground. Though it was built with pressure treated lumber it is getting soft. Should I just put a vapor barrier on the underside of the joists or should something go on the ground with crushed rock holding it down (instead or in addition to the vapor barrier)?
once the old deck is gone, check the level, the ground should slope away from the house at minimum 1/4 inch per running foot, and there should be no ponding in the area. if you have plain clay or loam under there, that held water and should have been excavated and replaced with gravel, etc.
sig: if this is a new economy, how come they still want my old-fashioned money?
Putting a vapor barrier on the bottom sides of the joists will make the problem worse. Water will be contained on top of the plastic. You won't like the results. A vapor barrier lying on the ground might give the same problem. Water can still puddle on top of the plastic and then have to evaporate. That'll do "you know what." If you have a roof over the deck the problem of water on top of the plastic goes away.
The best thing to do is to figure out how to get more air circulation under the deck. Getting good surface drainage by careful gradinag will give good results too.
JdN
Posts: 7439 | Location: Elkader, IA, USA | Registered: Mar 07, 2004
are there any gaps between your deck boards or are they clogged up? This could also prevent it from breathing if the boards were not gaped correctly or are clogged with debris. Also, is the bottom around the deck closed off with a wood soffit or is it open to the ground?
Posts: 208 | Location: Ohio | Registered: Aug 06, 2007
