I had a larger roof built over my old deck. New 6x6's were used to support the new roof. They set on cement filled 8" tubes set 40 to 46 inches into the ground. I have been told I have to use 2x8 beams and 2x6 as floor joists. This will bring my floor height with the added decking to my desired height.

I am told I have to notch the support posts. If this is done, I will be doing this at the top of the cement. Is this acceptable, or is it better to pour a cement slab for the porch? After this is done, I want to make it a 3 season room.

  • I like cement in this case because with a wood deck water and critters can get under the deck. Cement if done well will out last wood.
    – Ed Beal
    Mar 10, 2016 at 14:01
  • You're asking two separate questions here, and there's not enough information given to answer either of them with confidence. The second is mostly opinion anyway. Also, 2x6s are rarely appropriate as joists unless the span is very short.
    – isherwood
    Jun 9, 2016 at 18:19

1 Answer 1


Notch the support columns? 2x6's for joists when 2x8's fit? Yeah um, stay away from those people. Concrete would be best overall since it's impervious to most everything from water rot, to termites to air leaks.

With concrete you'd want to cinder block the perimeter, throw down 4"s of rigid foam insulation & pour a proper 4" thick slab on top of the insulation. However, there's no problem with wood either & that would be much more DIY-friendly.

With wood you'd do 2x8's everywhere & would box-around the support beams, definitely do not notch the supports. 2" rigid insulation would go on the bottom & on the perimeter frame, then fiberglass batts can fill in the rest.

  • "Yeah um, stay away from those people. " - Hilarious and very true! In addition, never ever, whether on a whim or by friendly advice, cut into any type of structural support beams. Unless, you are they are a structural engineer, I strongly advise against it. No point in risking a collapse for the sake of a patio. Sep 8, 2016 at 3:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.