View Full Version : wood moisture readings in LVL

Bruce King
07-04-2010, 07:21 AM
I did an inspection on a large new house that had major vented crawlspace moisture problems. The floor system has regular lumber and engineered lumber. The readings varied greatly but some areas had up to 28 percent. The builder had some fans installed to dry it out some and then had a sealed crawlspace installed. I went back for a reinspection and found a very humid sealed crawlspace with the supply air duct not yet installed. The regular wood had dried to 15-17 percent but the lower flanges/chords on the I-joists that have LVL type material were 20-26 percent still.

The builder disputed this and said LVL material will read higher moisture.
The builder hired an engineer that checked the whole installation but refused to check or report the LVL moisture levels because "his meter was not accurate for that".

I check these materials all the time and have no problem, in fact, I find the LVL to be a drier product to start with but once it gets damp it takes longer to dry out than regular wood.

This crawlspace simply needs a dehumidifier for at least the time it takes to get all the wood below 20 percent. The builder does not want to install one since code does not require it.

Anyone ever see any pin type moisture meters that can't check LVL material?

Jason Rockler
07-04-2010, 03:48 PM
Assuming this is a wide range issue and not just a localized problem:

All moisture meters are sensitive to wood density aka specific gravity. Pin type meters' readings are directly correlated to resistance, which is obviously affected by the type of material measured.

If I were you, and needed to prove I was right, I'd take some of that LVL that I knew was dry, and use a Wagner MMC220 (http://moisturemeter.com/mmc220-moisture-meter.html) or similar on a reasonable specific gravity setting. I'd show them that reading. Take it up to the crawlspace, and make them take that reading. It's always easier to get them to admit their wrong when they have the meter in their hand, and the 220 is easy enough for anyone to use.

There always will come a point, however, when you just give your professional opinion, and they can either ignore it or use it. That's life.

Ron Bibler
07-04-2010, 04:24 PM
I always use 2 moisture meters when doing this kind of work. One may go bad but 2 not a chance. put 2 meters next to each other if you have the same information. :D Done deal...

Another point to keep in mind on the materials. Most of this stuff is coming out of china.. Home of the bamboo boring beetle...

Keep your eyes open for little holes in the flooring.

See the attachment. I'm finding more and more of this. I get calls form people that are suing a floor covering company and need some one to make the ID... These little guys can hang out inside a board for 12 to 18 months and then pop out and be all over place by the thousands. infesting everything in the home...

The only way to correct the problem is to fumigate the structure with a tent and injecting a gas...very costly. and then remove all the flooring and install all .



Jason Rockler
07-05-2010, 12:08 PM
For that matter, most of the meters are coming out of china too. :) The only company I know that builds their meters in the USA is wagner (http://www.wagnermeters.com). Anyone know of anyone else?

Dom D'Agostino
07-05-2010, 12:38 PM
Hey Jason,

It seems every post from you is to "yak" about wagner moisture meters. What's the deal?