Hearth Slab Construction Question

[FiveOhFivePizza]

I recently poured the slab for my hearth. It sits on dry stacked ciderblocks and is reinforced with a lot of rebar. I have 2x4s with plywood providing tray support underneath. However, I forgot to use wedges to easily remove the supports. I saw a post where another user also did not use wedges and used a hammer to remove the posts and this may have cause cracking in his hearth slab. My question is, what would be the best way for me to remove the 2x4s and plywood tray supports? A mallet? Use a saw to cut them? And how long should I wait before removing the supports? Thanks for any help and advice!

[UtahBeehiver]

Sawsall the supports.

[SableSprings]

I agree with Russell on the use of a sawsall here but I suggest sawing 2/3 or so through then hit it from the other side to break it. I had to use this technique when my saw blade got bound up on one of my supports... amazing how much weight tension a slab can put on the supports! At least your hearth slab will be cured enough after a week to not need the plywood or braces any longer.