My mother's house was built in the early 60's and I noticed the steel beam in the garage supporting the upstairs floor joists is about 1/2" low and it appears when they set the beam in the concrete wall girder pocket they used some sort of mortar between the concrete and steel beam to help level it and that has broken and let it settle, my question is if I jack the beam up and clean the pocket what is best to put between the concrete and steel to relevel it?