ICE HOUSES AND 



be driven through the material. Cross cleats may be used 

 if the felt tends to sag from the ceiling, but should be re- 

 moved as the inside wood finish is put into place. Twine 

 may be used in place of cleats. Extreme care should be 

 taken in placing both the hair felt and the paper, for poor 

 workmanship will spoil the value of a high grade paper and 

 insulation. Hair felt has a great affinity for moisture and 

 when not protected from it absorbs it freely, displacing the 

 air. In this condition it becomes practically worthless as 

 an insulator. 



All good insulators are more or less porous and hence 

 must be provided with a perfect air seal to prevent the 

 entering of air and moisture, causing condensation and 

 consequent decay of the material. Paper is not a good insu- 

 lator. It merely serves as a seal. The requirements of a 

 good paper are that it be odorless, strong, durable, pliable, 

 ductile (not brittle). Papers which are rosin sized, oiled, 

 tar coated, or saturated should be avoided. Paper impreg- 

 nated with pure asphalt is the best and cheapest in the end, 

 as it costs less than five per cent of the total cost of the 

 insulation to use a high grade paper. When the paper is 

 applied the joints should be lapped at least 2 inches and in 

 some cases cemented. As water proofness and air tight- 

 ness are vital features in good insulation, the application of 

 the paper which controls these two factors to a large extent 

 is a very important part of the insulation. Asphalt for 

 waterproofing is worth about $40 per ton and will cost about 

 2.y 2 cents per square foot of coated surface. Good paper 

 will cost from $2.50 to $5.00 per 1,000 sq. ft., depending 

 upon the number of plies. 



FOUNDATIONS AND FLOORS 



It pays to build a good foundation and floor. The 

 earth is a fairly good conductor of heat, especially if satu- 

 rated with water, as it is sure to be below the ice house, so 

 insulation here is quite as important as in the walls. In 

 case only a dirt floor is to be provided, the earth should be 

 excavated to a depth of 12 to 18 inches. Fill in with cinders 

 or gravel and a few inches of straw or some material which 

 will prevent the sawdust from being washed down into the 

 cinders or gravel. The layer of sawdust should be 12 inches 

 thick. This will provide a foundation which is always dry 

 and it will be quite an effective insulator. 



Twelve 



