specifications. If your vehicle was originally charged with R12 refrigerant, for example, the oil type specified, 'mineral', will not apply. Additionally, General Motors issues Bulletin # 02-01-39-004B replacing PAG 150 oil with a lower viscocity oil.
The term square in reference to roofing materials refers to 100 square feet of roof area. One square of slate is the amount of slate that it takes to cover 100 square feet of roof area. A 10 foot x 10 foot section of roof would equal one square. So would a 4 foot x 25 foot section. Ditto for a 5 foot x 20 foot.
Roofing felt is designated by the weight per square. As we mentioned earlier, a square is equal to 100 square feet and is the common unit to describe the amount of roofing material. Roofing felt is commonly available in rolls of 15 and 30 pounds per square. The rolls are usually 36 inches wide.