CleanSpace-drainage matting installed under the CleanSpace liner proves many benefits. It creates a drainage space under teh CleanSpace for water to flow to SmartPipe or SmartSump. Adds Durability and puncture resistance (great for covering rocky soil too). Creates air space that acts as a thermal break giving some insulation value. Provides a comfortable cushioning for your knees when crawling on it. It is a Patented solution.