Expert: Bruce E. Johnson - 6/14/2010

Question
We want to build a wood deck over and existing concret patio. 2 sides of the deck will extend about 4 feet past the existing concrete. We have a patio cover with ceiling fans and we do not want to "raise" the height of the new deck too much, the minimum possible. We plan on using 5/4in x 6in PT decking, can we use the same dimension deck boards as the "supports" to secure the deck?

In other words, we would lay the 5/4 x 6 decks boards on the existing patio every 4 ft. and secure with concrete anchors. These boards would be supported by concrete blocks on the area where it overhangs the existing patio. Afterwords we would lay the actual deck (same dimension deck boards) across these supports and secure with deck screws. The total height added would be about 2 1/2".

Most people would use 2x4 or 2x6 for these "supports", just want to make sure there would be no issue using deck boards instead of 2bys..

thanks.

Answer
Hi Leo, the 5/4 should be okay but I would space it at 24" instead of every 48", 5/4 doesn't span 48" and your deck will feel spongy.  Also, it is important to run your "sleepers" with the slope of the concrete so water will continue to drain properly.  I hope this information helps please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com