Abstract: The present invention features a drainage and support mat used as a supporting and drainage surface beneath sods, plantings, gravel and roofs and decks of concrete. The mat is made of a high-impact plastic sheet such as polystyrene, PVC, PET, etc., and consists of evenly spaced, upwardly projecting, dimple-type protuberances. Channels that are formed between the dimple projections allow water to drain off the mat surface. For greater support and load-bearing capacity, the dimples have a substantially truncated, trapezoidal or hemispherical shape. The flattened, truncated portion (upper surface) of each dimple normally retains a small amount of drainage water. To counteract this, each of the protuberances of the mat has a slotted section in or adjacent to it. The slotted section crosses the flattened, truncated portion of the dimples, allowing any accumulating water to run off and down the sides of the protuberance.

Abstract: An improved hydraulic cement is provided for use upon admixture with aqueous media, preferably either water or aqueous latex, and primarily comprises a hydraulic cement, a polyethylene oxide homopolymer and an alkyl derivative of cellulose, preferably a hydroxyalkyl cellulose.