Drainage board which posses high stength ,high compressive strength and doesn's distor or burst molded PP as a protective material for water proofing and provides ventilation for conctete slabs which alleviates heat induced stress and cracking ,Futhermore if the wall is cracked and no efficient drainage is present contamination from the soil such as salts and other corrosive elements will futher contribute to the deterioation of the wall integrity,Drainage board are the most effective method of venting and maintaining consistent temperature on the wall surface by creating a substaintial long term air pocket that will hot crush over time.