Facilities for Storage (from a USDA bulletin)
A variety of facilities can be built or adapted for home storage. The type of storage built depends upon the climate and the choice of the individual. Elaborate facilities for home storage are not practical unless outside temperatures during the winter average 30° F. or lower to permit proper cooling. The size of the storage space will vary according to family needs.
The principles for successful storage apply to all facilities. For example, the cooling of the storage space and maintenance of a desirable temperature depend upon the outside temperature, the manipulation of the ventilators, and the extent of insulation against undesirably high or low temperatures. Proper drainage and the exclusion of light and rodents are also important.
Storage in a Home Basement
A well-ventilated basement under a modern house with central heating can readily be adapted to home storage needs. The furnace room is an excellent place to cure sweet potatoes, pumpkins, and squashes. After curing, however, these commodities should be moved to a cooler part of the basement. Temperatures in ordinary basements vary in different parts of the country. In basements, temperatures ranging from 60° to 70° F. in winter, when the furnace is in operation, and 70° to 80° in summer are perhaps average. While too warm for most commodities, the regular basement is satisfactory the year around for holding potatoes, sweet potatoes, and onions for short periods, and for ripening tomatoes.
If the basement is to be used for winter storage, a corner should be partitioned off and insulated so that the storage space can be kept sufficiently cold. The storage room should be located preferably on the north or east side, and should not have heating ducts or pipes running through it. At least one window is necessary for cooling and ventilating. Two or more windows are desirable, especially if the room is divided for separate storage of fruits and vegetables. The windows should be darkened to protect the produce from light. They should also be boxed or shaded in such a way as to prevent the entrance of light even when they are open.
Bins may be used for storing certain commodities, but crates and boxes are preferred, as it is possible to remove them for cleaning. Equipping the storage room with shelves and a shitted floor keeps the containers off the floor and provides free air circulation. It also permits the use of water or wet materials, such as dampened sawdust, on the floor to raise the humidity.
Storage Cellar Under Home Without Central Heat
The old-fashioned cellar beneath a house without a central heating system has long been used successfully for winter storage of fruits and vegetables in the colder parts of the United States. The cellar usually has an outside entrance and a dirt floor. The outside doors serve as a means of ventilation and to regulate temperature. Some cellars have no windows, but if present they aid in ventilating and in temperature control. Windows are especially needed if the cellar has a partition to separate the fruit and vegetable compartments.
The precautions regarding light, drainage, and insulation described under “Storage in a Home Basement” also apply to the cellar under a house without central heat.
Outdoor Storage Facilities
Outdoor storage facilities can be constructed above ground or partly or entirely below ground. Cellars constructed below ground are superior because they can maintain a desirable temperature longer and more uniformly than any other type of home storage.
Outdoor storage facilities may be attached to the house or located in the yard or under an outbuilding. They should be convenient to the kitchen, and have proper drainage and insulation.
The structure of an underground cellar must be strong to support the weight of earth over the roof. Stone and masonry block in combination with concrete can be used, but a structure made entirely of reinforced concrete is best. A variety of plans can be developed. In the plan illustrated in figure 1, the cellar is attached to the house basement. This structure can also serve as a storm cellar or protective shelter against radioactive fallout in case of an emergency.
The whole structure, with the exception of the door, is covered with earth to prevent freezing. The thickness of the covering varies according to geographical location. In northern sections of the country, 2 to 3 feet may be necessary. Straw or fodder may be used for additional insulation if necessary. Wire screen over the outside ends of air intakes and ventilators will keep out birds and small animals.
Partly Underground Cellars
One type of cellar that can be used in certain northern sections of the country has walls of masonry that are partly below and partly above ground. Earth from the excavation is banked around the walls that are above the normal ground level and one end is left exposed for the door (fig. 2). As in other storage houses, an air inlet and a ventilator should be provided for each compartment, if there are more than one. Proper provision for ventilation is illustrated in figure 1. The double door is insulated.
Figure 1.—Longitudinal section and floor plan of concrete storage cellar that can also serve as a storm and fallout shelter.
Figure 2.—A partly underground storage cellar with stone walls and insulated frame roof.
Storage Above Ground
Aboveground storages can be built of masonry or lumber, but must be well insulated. Even masonry walls, regardless of thickness, have little insulating value. The following discussion is applicable where the climate is consistently cold, but where the average temperature- does not drop below freezing. Even in these climates the minimum temperature may drop to zero or below, and supplemental heat may be needed on very cold nights. Thermostatically controlled heat can be used if electricity is available. Only a small amount of heat is necessary to prevent subfreezing temperatures, and the storage temperature should be watched closely when low temperatures are predicted.
Hollow masonry construction such as cinder block provides the simplest means of installing insulation. Vermiculite, or some other dry granular material, can be put in the vertical channels formed by the alignment of the blocks as each course of block is laid. If cinder block is used, the inside and outside surfaces should be scrubbed with a cement grout to make them less porous. After the walls have been scrubbed with cement grout, the inside of the walls should be painted with aluminum paint to serve as a moisture barrier. Tar paper should be placed between the ceiling and joists as a moisture barrier, and at least 12 inches of dry sawdust or other granular material should be spread in the attic above the ceiling.
A frame building can be built of 2- by 4-inch studding and rafters. “Walls can be made tight by sheathing both the inside and outside of the frame with matched lumber. The space between the inside and outside sheathing should be insulated with loose fill or mineral wool blanket. Laminated kraft paper with asphalt between the layers, aluminum foil, or polyethylene should be placed between the insulation and inside sheathing as a moisture barrier. Building paper over the sheathing in the roof and outside walls is of great assistance in making the structure tight. The interior can then be painted with aluminum paint or whitewashed.
Ventilation for any aboveground storage building can be provided by the same type of roof flue and floor inlet that is recommended for concrete cellars (fig. 1).