I am planning to build my blockof plate this weekend when it gets warm again---70's--. I have had people reccoment rockwool to me for an insulation to stick up above the plate. Call several stove shops and am told that's not what I need. One is trying to sell me on a vermiculite installation above the blockoff plate another said to pull the liner out and but a wrap insulation on it. I explained that it was likely to be there till the end of time since it was an ovalized 8 inch that we pulled into a 6 inch wide clay liner. When he realized that I had done it his tone changed to a very condecending one and he just didn't seem to want to help me any more. As though a homeowner is going to be incapable of doing this but the fat toothless illiterate freak with all the prison tattoos they send out to evaluate the place for a quote is gonna have it all worked out. What the heck to these people think was done before their cottage industry sprang up to save us? We fix our homes. We do what we have to do. Hiring someone to do all your work is a luxury that most Americans could not afford except in the last 20 years. And after all my anger and indignation fades away.....I still dont' have an insulation to use for the block off plate. IS this a material like fiberglass batting(although not glass based) or is it board like and I cut it. I am irritated.