Hope this post finds you and your loved ones well.
The subject is Spray Foam Shrinkage.
It is a clean crawlspace, but will under preform.
It was a poor attempt to create an optimal Crawlspace environment. Falling grade.
Crawlspace. Poorly processed. From the grade soil to the insulation and conditioning.
1: A crawlspace requires conditioning and Venting in most areas of North America, to optimize performance.
2: The insulation should have been on the walls. Not between joist bays.
3: The spray foam applicator was not trained. Very uneven blanket.
As for the Moisture Properties of Wood. Wood is hygroscopic.
Wood moves within it’s environment, among other things durability related.
From an Article: Moisture properties of wood: Wood contracts and expands in different ways in the radial and tangential directions of the growth rings and in the direction of the grain. This phenomenon goes by the name anisotropy. As it dries, wood shrinks from being completely wet to absolutely dry, in the tangential direction by an average of 8%, in the radial direction by about 4% and in the direction of the grain by only 0.2-0.4%. Heartwood is always drier than surface wood, which makes wood drying challenging. Anisotropy and the internal tensions of wood are also caused by the warping of the wood as it dries.
The fiber-saturation point of wood, and for most species, is in the vicinity of 25% to 30% of the oven-dry/Kiln dry weight of the wood.
Very interesting subject, Scott.
Civil Engineering article. Effects of Hygroscopic Properties of Wood. Enjoy.
Here are 2 photos from yesterdays ancillary home inspection. Build. 1954. 1.5 story bungalow. Owner preparing to renovate the basement.
Heavily Checked Girder. Rear of the property.
The last girder span, roughly 7’ feet long between the last rear steel column and where wood girder entered the poured concrete foundation wall.
*Note: The wood in the concrete was visibly rotted. No probing required.
Hypotheses - Checking. The girder having reduced load-bearing capacity and saturated numerous times escalated the checking in the girder.
The rest of the girder was not checked.
There are 2 girders.
Post images as the work proceeds.