saag wrote:
I dug 3 holes in the crawlspace under my kitchen to help support a
floor that I found out sagged when we had the kitchen ripped out &
redone. It's a total span of 8 feet.
The circular holes are about 18" deep & 18" in diameter. I wa
splanning on filling then with concrete then buying 3 of the small size
jack posts that HD sells and placing two 8 foot 2x6 beams on them.

My question is does it matter if the wood beams lie flat on the support
posts or on their bottom edge?

If you intend to lay the 2 x 6's flat you will effectively have 3 1/2"
to support the floor. Doesn't it seem more logical to have a full 5
1/2" support the other way? Nail the 2 x 6's together, naturally.

Also how many pounds of concrete would it take to fill the 3 holes? thanks

Do the math: most Quickicrete or whatever is .8 cu ft. per bag. So 3
1/2 bags would be about right. YMMV.

Joe