Expert: Bruce E. Johnson - 4/30/2009

Question
QUESTION: I live in a new house I had built out in the country a few years ago.
My problem is the floors in some areas creak, sometimes badly. Most, if not all of the creaking is within 10-12 feet of the outside walls, along the main beam. They didn’t creak initially but started within 6 months. Should I be considering adjusting the main beam supports and if so, how is it done?


ANSWER: Hi JA, it's possible that there is some settling going on..If you have access to the support beams it is easy enough to see if the posts holding up the beams have play in them or are still under pressure.  Some hardwood shims can be driven between the beam and the post or between the post and the footing pad to take up any slop.  Or in the case of severe settling a hydraulic bottle jack can be used to jack up anything that is way out of whack.  Creaking floors though are usually caused by improper nailing and gluing of the subfloor plywood.  You didn't say what kind of subfloor sheathing was used in your place.  I prefer 3/4" tongue and groove plywood glued with construction adhesive and nailed with ring shank nails or screwed with deck screws.  If you can get under your house and locate the areas that are squeaking, shine a light up at the floor joists where the plywood meets the joist.  Have someone jump up and down in that area and see if the plywood is moving up and down and the joist is stationary.  If the plywood is moving then it has become loose.  A fix for this is to get some construction deck adhesive in a caulking gun tube and try to inject the adhesive between the plywood and the joist.  Then stay off the floor in that area for at least 24 hours to let the glue set up properly..I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com

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QUESTION: I have a full basement and the bottom of the floor and the wood main beam is, for the most part, fully accessible. The main beam supports appear to be adjustable. If I find a need to adjust them is this as simple as turning them or is there a need to jack up the beam first? Since there are 4 main beam supports, if I adjust any of them do they all need to be adjusted and if so, in any particular order?
I,m sorry for my slow response I've been trying to get my fields ready for planting.

Answer
Hi again JA, if you are certain that the main beams are settling and need adjustment you can do it manually as you suggest.  It is a slow process you give each column a quarter to a full turn and in sequence starting at the column or post shore that is underneath the joint where your beams butt into each other.  These are the main posts.  Do all the main posts first.  This act will move the beams up.  Then any intermediate supports need to be snugged up tight enough so that you feel pressure on them.  Then repeat the process until you get to where you need to be.  Pulling a tight string line or shooting a laser beam along the beam lines will enable you to see where you might have some sagging in your floor system. I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com