My smelly house woes continue. I've cleaned out the crawlspace of debris (failed ductwork etc.,)

I have cleaned it out and have ordered borocare to spray on all the joists.

Since my crawlspace is belowgrade on all sides but one there are only two tiny vents. I started installing 6 mil poly (from Home Depot) and now I find that there are better ones available- cross laminated something.

Does anyone know where I can find these in the Seattle area ? What do I ask for ? Are there any brands you would recommend ?

I plan to cover the foundation walls with it and attach it with a furring strip. I understand that I need to leave a 4 inch gap from the wood on top of the foundation for termite inspection.

I am really looking forward to doing this- feel like I am accomplishing something ! :)

Thanks all