I just finished tearing apart a deck made of PT joists and western red cedar decking. I know it was WRC because I could still read the mill stamps. It’s my first time with cedar. Deck was about 10 YO and built directly on the ground…the PT joists were supported by either the dirt or a flush patio slab. Essentially no ventilation. The cedar was rotted very badly, to the poiint of almost being unsafe to walk on. I thought cedar was supposed to be naturally rot resistant?
Replies
It is rot resistant, but only to a point, especially if the wood is second-growth, and/or it contains any sapwood. And even oldgrowth heartwood will decay after while in the conditions you describe (close to the ground) with ground moisture creating a damp environment on the underside of the deck. It's also a good testimony for sealing the undersides of deckboards before installing and then cleaning and sealing the undersides (if possible) during future maintenance of the tops.
I recall reading a piece somewhere (FHB or JLC) a couple of years ago about deck maintenance by a guy who, as part of his deck maintenance work, crawls underneath, power washes and reseals decks before climbing out, changing clothes and doing the top surface. (Sounds like real enjoyable work!).
I believe "Dirt-pigs 'R' Us" performs that particular task, only asking for contributions of Tequila and biscuits...If it is to be, 'twil be done by me..