To be usable and comfortable a basement should be dry. Cynics may insist that dry basements cannot be built, they just happen, but fortunately there are contractors who have proved the inaccuracy of this view. With extra care and good design a dry basement can be guaranteed, and conversely, inefficient construction and poor workmanship can completely nullify all drainage and waterproofing measures. To ensure a dry basement there are a number of factors to which close attention must be paid during construction. The most obvious of these refers to selection of the site. The highest point on a given plot of ground should be favored over the low spots, especially in localities where the water table elevation is high. Correct grading of the site is of the utmost importance. Backfilling the excavation will almost inevitably mean that the filled area will be of a much more porous nature than the surrounding undisturbed earth. Finish grade must then be so sloped that no water will stand close to the building and most of it will run off. It is also important that the run-off from down spouts and roof gutters be diverted away from the basement walls by means of splash blocks extending at least three feet away from the building, open gutters, or, better still, underground drainage tile. Basement walls and floors, properly constructed of ordinary reinforced concrete, are themselves highly resistant to the passage of water. But for the residential basement, it is essential to provide some extra protection except where the very mildest conditions prevail. The simplest of these, known as integral water proofing, is equally applicable to slab construction, and consists of including in the mix any one of a number of admixtures intended for the purpose . If waterproof coatings are to be used, they should be applied as long as possible after the concrete has been placed. Another effective material is a heavy, cement-base aggregate type of waterproof coating that is specially formulated for below-grade foundation use.