Contractor Rob Robillard also discusses lally column replacement. For more expert home improvement advice, go to realestate.boston.com.

Q. The outside of the Lally columns in my under-the-house garage have rusted out at the bottom. The inside concrete looks OK, but is the outside steel layer important? GUEST, in Hotton’s chat ...

A: Lally columns are made up of a steel tube filled with concrete. The steel is most important, because any concrete inside the steel tube is too small to hold up without the steel.

A lally column is replaced by a larger ridge beam for an open kitchen and dining area. Great progress is being made on the project house. The primary addition is being framed and the rooms are ...

Adjustable steel columns, also called jack posts or lally columns, can be installed in basements and crawl spaces to support sagging floors or can be used as a fulcrum beneath heavy appliances.