"Tod and his capable crew were great. Our house has a craw space under the basement wood floor. In the crawl space they installed perforated pipe under a membrane over the 1700 square feet. They connected the pipe to the fan. Radon levels were reduced to less than 10 Bq/m3 immediately. They worked in the cramped space and did it over two days and all for the estimated price. Thanks RadonProz."