In this last installment of the ICF (Insulated Concrete Forms) video series, you will see the final and critical step in foundation waterproofing. Applying the Poly Wall Arroyo Drain Board is the final step to ensure your ICF foundation is completely waterproof. As you can see, the bulk of waterproofing was completed with Polywall Home Stretch Waterproofing Membrane.The Arroyo Drain Board, a polypropylene egg crate material, consists of a dimple mat that will be installed on top of the waterproofing. There's also a filter fabric on the opposite side of the dimple mat, which provides another barrier between dirt and rocks when you backfill the foundation. This drain board allows for an airgap between the dirt and the foundation and provides a channel to drain water away from the house. As you'll see another unique feature of the Arroyo Drain Board is a dimple size in the bottom foot of the mat, which is where the majority of water would be.Another benefit of this drain board is that it protects the Poly Wall Waterproofing from the backfill process—you don't want to penetrate that waterproof membrane!This system has no fasteners or penetrations. All you need is Sta’-put spray adhesive. Watch as they spray the adhesive on the wall and on the back of the arroyo drain. Once both surfaces are tacky, it's ready to apply. Check out the whole series of ICF videos to see the form come together from start to finish.