Without a proper drainage system, water can damage virtually any construction project. A drainboard controls the flow of water, taking it out and away from the foundation. Behind the drainboard, waterproofing remains soft to some extent and is susceptible to cold flow under pressure. Rather than breaking or cutting, some waterproofing material may flow into the drainboard dimples over time, form a bubble, and eventually burst – compromising the waterproofing system. To prevent this from occurring, a special type of drainage board with a protective polyethylene sheet must be applied.