Hemlock can have higher moisture content than most other native trees, causing them to sink. Hemlock lumens have large pits (valves) that allow easy transport of water into the wood.
Bigger rings = bigger lumens. Younger hemlock or hemlock tops are more susceptible to sinking. The bigger the rings the more likely to take on water.
This study involved the on-site evaluation of commonly employed equipment and procedures for evaluation of moisture content in solid-wood products. Specifically, a DC-resistance and two RF-based moisture meters were evaluated. The main overall objective was to identify procedures or develop information to allow more accurate final MC estimates to be determined. Lodgepole pine lumber of 25 and 40 mm thicknesses was employed for the test Material was tested at three time intervals spanning from the completion of drying to approximately 30 hours after drying. Meter readings were compared against oven-dry moisture contents. In most situations the moisture meters employed tended to underestimate final moisture content with the error varying from close to zero up to about 3 percent. The errors observed seemed to be consistent for a given test. This opens the possibility of employing site-specific correction factors to obtain better estimates of oven-dry moisture content. Problems may still arise when comparing mill results of moisture tests against those performed elsewhere by customers and end users.