green schmeen

[pwood]

the new green code requires the framing to have no more than 17% moisture content before closing up walls. are inspectors being outfitted with moisture meters to check every stud, headers, plates, rafters, joists, subfloor, roof sheeting,etc... for the proper moisture content? how much time do you spend playing with your meter?

are any ahj's using a self-certification form or affidavit that is completed by the contractor or owner builder and submitted at the time of the framing inspection? inquiring minds want to know! thanks!:banghd

 

[mtlogcabin]

Been in the building code for years

2006 IBC Table 1604.3 footnoe d. For wood structural members having a moisture content of less than 16 percent at time of installation and used under dry conditions, the deflection resulting from L + 0.5D is permitted to be substituted for the deflection resulting from L + D.

 

[pwood]

mtl,

i think this has to do with mold and moisture issue, not structural issues?

 

[conarb]

i think this has to do with mold and moisture issue, not structural issues?

Correct, with our new building sealing requirements walls aren't "breathing" any more, so trapping moisture in walls can start mold growth.

 

[Mark K]

The California green building standards known as CalGreen requires verification of wood moisture content <= 19% before enclosing the framing. CalGreen is an overlay on the California Building Code.

 

[mtlogcabin]

mtl,i think this has to do with mold and moisture issue, not structural issues?

Doesn't matter if it is for mold or structural 16% was the max. Did you carry a moisture meter and check them then? Inspectors do not check everything and I would suspect very few check moisture content for what ever reason it is in the code

 

[Mark K]

There is a structural concern.

If fasteners are installed in green lumber they will have less capacity than fasteners installed in dry lumber. This cannot be resolved by waiting for the lumber to dry. Thus if the lumber was specified as dry and the test shows that the lumber is not dry the building official would have reason to require a review to determine whether the fasteners are strong enought to resist the required loads.

The question is whether the IRC provisions were based on dry or green lumber.

In California because we are close to a number of mills so green framing lumber is readily availible.

 

[conarb]

In California because we are close to a number of mills so green framing lumber is readily availible.

Mark:

We have always framed with green lumber and most of us consider it superior for framing, allowing the building to dry-out together as a unit, this works with custom building but tract builders close in so quickly that they had some problems. One of the driving forces behind going to drier lumber was the intermingling of engineered lumber with with green lumber. My SE recently specified a moisture content of <19%, I asked him to allow green lumber since we have no engineered lumber and were substantially over-designed for any fastener problems, he refused. Since I refuse to use KD lumber for framing I have to use S Green to get my necessary <19%, my supplier states that S Green is guaranteed as <19% whereas green can go as high as 25%, funny how we built buildings for centuries with green lumber and now we can't do it anymore, there were sheetrock nail-popping problems with green lumber, but we solved that with sheetrock screws.

 

[Mark K]

I would get your supplier's guarantee in writing and confirm it by performing some moisture content tests. The Western Lumber Grading Rules 98 states that S-GRN indicates that it was in excess of 19% in moisture content when it was surfaced so a S-GRN stamp is not sufficient proof of compliance.

 

[peach]

mold leads to rot.. it becomes a structural issue.