The loss of height from shrinkage alone in most cases should be less than 1”. This can vary depending on the overall moisture content of the lumber at the time of construction.

There will be some additional loss of overall height, from an exterior stand point, due to settlement of the foundation. This will depend on the type of soil it is placed on and how densely packed it is.

Glenn,
Thanks for the reply. What then happens if sheathing or T1-11 siding is nailed from top to bottom with tight butt-joints (with z-flashing), and then the joisting shrinks?

When applying T1-11 you use a horizontal “z” strip between rows. This strip is for flashing against water infiltration and can also be used to hide a crack of about 3/16”. Do not butt the T1-11 tight against the row below. Allow a little space for expansion or in this case contraction of the framing.) You also should not butt the top of the siding tight against the roof framing at the overhang so you already have some room there too. Always leave a caulk joint around the perimeter. The T1-11 will also be a little forgiving. You should have no problems.

[This message has been edited by GlennG (edited March 21, 2002).]

Aha, then the contractor who built my house would have been negligent in butting the siding tightly together. In putting new baseboards all around the interior of my second story, I've noticed that the sole plate on much of the perimiter has separated from the 2nd story subflooring. In addition, where the upper and lower sheets of siding meet at the z-flashing, there appears to be some bowing outward of each sheet, likely from the incredible compression between them. I'm guessing that a good portion of my load is being transfered through that point instead of through the framing. (Lots of creaking, 5 years after construction.)

Do you know a good construction atttorney in Seattle?

Better yet hire someone to cut the T-111. To try and prove negligence on the framers part would be next to impossible. Was the house built in the wet season? Did he leave 1/4" clearnce?
Set the saw at 5/8" and trim off the bottom 1/4" of the siding.

DH may be right. The fix should not be overly expensive. Care must be taken not to cut into the “z” flashing or you will open up a whole new set of problems.

If the house was done 5 years ago you may have a little difficulty with a legal case unless the contractor was notified about the problem in the past and did not repair it. If you do want to pursue the possibility of legal action:

1. First, getting a copy of the installation instructions for the T1-11. Then if the manufacturers recommendations were not followed and there is clear evidence of that fact you may have a case.
2. Get several estimates for repairing the problem as well as a written statement from the contractors stating exactly what was causing the problem and their estimate to repair it.
3. And above all take plenty of pictures showing the problem.

Depending on the laws in your local, if the warrantee period has expired you may want to have a brief consultation with an attorney before filing the case.

Glen,
How would you specify wood to use on a new home to minimize shrinkage? and how would you know whether the wood is dried to those specs? Any hints?
Bill

Ask the salesman at the lumberyard to supply you with a "wood material certificate" for the wood you are going to purchase.

This certificate should show:
· Specie of wood
· Grade
· Moisture content
· Minimum allowable unit stresses allowed by American Lumber Standards Committee.

The wood you are going to use for framing should comply with the following:
· Comply with American Softwood Lumber Standard PS 20 with grading rules as certified by the American Lumber Standards Committee (ALSC)
· Maximum moisture content to be no more than 19% at the time of dressing and also at the time of installation. (Must be kept covered and dry until installed.)
· No. 2 grade or better.
· Stress grade 1200-psi minimum.

Any good lumberyard should be able to get this information for you directly from their suppliers. The major lumber suppliers will conform to the certificate they supply or they could be held liable for any resulting damages.

Glenn Good