we are closing in an existing covered deck to become our livingroom. the cement sonotubes that hold the 6x6 posts are 10 across and are 4 in. above the cement floor. we are pressed for head room so can not build a subfloor up to them. i was wondering if i can chip the cement so that they will not be sticking out of our 2x6 wall construction. i am worried about compromising the support system by doing this?? another option i thought of was to use 2x10s for the walls. which would mean doing extra work around the windows as they are made for standard 6 in construction. any advise or ideas would be very helpful, thanks.