To provide for cleaning water, or for any other moisture that may get in at any time, a tile drain leading outside the basement wall should be provided.
Securing Dry Cellars. In localities where a porous or sandy soil exists to the depth of six or more feet, cellars are usually dry without the use of any preventative to dampness; but where compact soil exists, usually about 80 per cent of all present cellars are more or less sub ject to dampness, as few have been water proofed. That concrete, like brick and stone, is a conductor of dampness is known; but that it is more readily adapted to waterproofing only those experienced in waterproofing walls below the grade line have appreciated.
Physicians have long realized that a large amount of sickness is caused by damp cellars, but as waterproofing does not add to the appear ance while adding to the cost, it is usually omitted, though medical bills more than make up this additional cost in a few years.
In the illustration, Fig. 5, it must be remem bered that the piping shown is for drainage only, and no provisions are shown for sewerage plumbing, which will require separate piping and should never be connected to the drainage sewer nearer to the building than beyond the last trap shown.
A monolithic concrete wall below grade is the cheapest and strongest; and when water proofed on the outside and on the top with the offset shown, with any positive waterproofing, it will insure dry walls. It, however, causes water to remain on the outside, which is also injurious to health; and nothing but proper drainage will overcome this evil.
Perhaps the best method of securing the necessary drainage consists in loosely placing crushed rock against the wall, with a four- or six-inch porous drain tile, joints not cemented, placed in the bottom of the trench. The drain tile must have no less than one foot fall or drop in twenty feet. The size of the drain tile depends upon the length of wall, and four-inch is sufficient for buildings less than sixty feet long.
In localities where clay soil or hardpan is found, it is necessary to place another drain six feet from the building wall, which is placed in a trench of sufficient depth to be free from frost; this drain is also covered with crushed stone or brickbats, allowing space to cover with soil of sufficient depth to insure proper nourishment for the lawn. There are numerous materials
that can be used for the porous fill, crushed sandstone or brickbats being perhaps the best; but gravel or coarse cinders are acceptable.
In no instance should any part of the drain nearest the wall be above the cellar floor level, but it may be much lower, the outside or lawn drain depth being governed by frost depth.
The cellar and conductor drains should be made of socket sewer-pipe well cemented at the joints, and have a trap at every opening on the inside of the building, and one trap after all connecting drains have been entered into the outlet; and this trap must have a vent-pipe to prevent the formation of noxious gases. Some contend that the conductor pipe having an iron pipe from the grade to the eaves of the roof, makes the best vent possible; but drains connected with street sewers often carry gases from the sewers when the traps are not water sealed, in which event the conductor would be an outlet for such gases.
Waterproof Cellar near a Stream. It is fre quently necessary to build a cement cellar close to a stream where water is liable to seep in from the bed to the bottom of the cellar when the water rises during the spring freshet. Waterproofing for basements so located must be strong and well made, as it must resist pressure. A good method is to apply the water proofing on the outside of the wall, covering same with cement plaster as shown in Fig. 6. On the bottom apply the waterproofing on the concrete body, and cover with the half-inch cement finish (wearing coat). Care must be taken to cover the entire surface to make it absolutely water-tight. On old walls and floors, the waterproofing must be applied on the interior.
The use of sheet piling made of wood, with a sheet-steel shoe for each plank, and a driving cap of sheet steel as shown, saves labor, time, and cost on even the smallest job requiring crib bing; but on large work, sheet-steel piling should be used.
When it is necessary to operate a continuous pump, the footing concrete should be mixed and placed dry; thus it may be placed when the trench is filled with water.