I built my beam using 1/2" ply and it had a twist because of my uneven concrete garage floor. I had space in my forms tho so figured I could allign. Got about halfway done and noticed the last half of forms were off by the same amount and were adjusted as far as their slack allowed. I sawed the beam in half and put it back together with four straps inbetween forms with sheetrock screws while taking out the slight twist. All straight now.