Tom has a pretty extensive knowledge of the materials he works with. Within just a ten minute phone conversation he'd ironed out the best candidate material for a "science project" I had in mind for my roof. I thought Tom's sarcasm made for some amusing conversation, and was nothing like the description from the last fellow that rated these guys. On the whole, I found Tom to be knowledgeable of his work and very helpful with a layman on materials like myself. I'd definitely return for future projects.