SAL TESTAVERDE, Georgetown

A. The cracking is normal in large wood beams. When they dry out, they contract; when they take on moisture, they expand. This expansion and contraction will cause cracks, mostly in beams and posts, say, 6 x 6 and larger. There is nothing you can do about it; painting may help keep moisture out of the wood, but don't count on it. The cracks will not weaken beams.

One thing you could do is box in the beams with 3/4-inch-thick boards. This will cover the beams but won't cure the problem, but since it is not a problem in the first place, why bother.

Q. I am boxing in a beam in my basement. How can I butt the bottom part of the box against a round Lally column, which I do not plan to box in?

C.H., Billerica

A. Try this: Cut the bottom board a little longer than the space provided between column and the other end of the beam. Measure the diameter of the column amd draw a half circle at the end of the board, right in the middle. If you make the cut correctly, the half circle will fit perfectly against the column. Then cut the board to length so it will fit in the space provided. Do the same with the bottom board on the other side of the column.

Q. The main beam in my 1900 house has old cedar posts under it, and are getting somewhat punky. I plan to replace them with lolly columns. The old posts were sitting on the biggest rock possible in my basement. Can the lolly columns sit on the rock where the posts were, or do they need their own footing?

JIM HOLLAND, Dedham

A. If the posts sat on the rock for 98 years, and the beam did not move, there is no good reason not to use the rock as a base for the new columns. Make sure the rock is flat where you put the columns so they won't skid around. If there were some posts set on earth instead of rock, then you have to build a footing for the new ones. A concrete footing (one for each post) should be 12 inches deep and 24 inches square.

Since the rock may make the distance between it and the beam different in different locations, you might be better off using screw jacks, which are adjustable, rather than lolly columns, which have to be cut to fit. Generally, codes require that the screw jack mechanism be welded to make sure it will stay put.