We had major water damage and are working with our insurance company to replace the original hardwood flooring. I am insisting that they place a layer of soundproofing insulation where the sawdust once laid under the original floors (about a 2 -4 inch space). There are two reasons: 1) to prevent sound reverb from floating up from the neighbors below us (this is a third floor condo); and 2) to prevent drafts from our North-facing French Doors during cold Indiana Winters.
The insurance company, however, does not see the need (surprise). They insist I provide "expert" opinion that the sawdust layer did anything, and what would be an equal replacement.
Does anyone out there know about the history of using sawdust under hardwoods dating around 1920? Did it provide a layer of insulation and soundproofing? My common sense tells me it did, however, I need more.
Thanks so much for your opinions! I've attached a couple of pics. One is with the layer (damp) and one is the sawdust removed to show the space I want filled.
I tried to attach two photos, however, the uploader did not work. Instead, I put them up on my work website at http://aboutgsquared.com/hardwood-flooring-sawdust-layer/