Masonry Magazine October 1969 Page. 14
Data Sheet (Continued) No. 1
When the building frame was finished, wood-framed polyethylene panels were wired to it, with the metal floor deck serving as a roof. Masons then began to lay an interior wythe, while outside scaffolding was erected to permit laying the outer wythe.
After the inner wythe was completed, the panels were unwired from the frame and refastened to the scaffolding. The corners of the panels were reinforced with plywood, affording not only additional stability but a simple method for attaching the necessary wiring.
According to the Salvucci firm, a member of MCA of Massachusetts, panels are more flexible than polyethylene sheets. For example, they can be unhinged from the scaffolding and swung open to admit materials delivered via high-reach forklift. The corners of panels are reinforced with plywood and fastened to scaffolding with wire.
The Salvucci company uses two types of panels: a prefabricated 7' x 6'7" version, and a custom-made variety. Its own men build the panels, up to 90% of which are generally reusable. The cost of unreinforced panels is $12.33, including labor and materials, and about $2.00 more for the stronger panel. Cost of erecting and dismantling comes to about 5¢ per sq. ft.
On the Jordan Marsh building, only the scaffolding where the masons were working was covered to conserve panels as well as heat. The working space was sectioned off into an area 200' by 17' high. It was then heated from the inside by ducting hot air through holes left in the inner wythe.
Panels cover only the immediate working areas. Materials were delivered by fork-lift through openings in the coverings made by unhinging panels. Total protection cost ran about 1% of total contract cost.
Portable oil space heaters were used during work days, when the temperature was 40° and falling. When the sun shone, it warmed the enclosure, so the heaters were turned off. Hourly cost for five heaters, according to the Salvucci firm, was about $7.70, including the cost of one union operating engineer at $6.00 per hour.
Masonry units and mortar materials were kept dry by storing them on pallets and covering with tarps. Sand was delivered daily and was protected by a plywood and building-paper roof, which survived the snow and high winds. The sand was heated before use by piling it on a metal culvert through which hot air was blown. Water was not heated, but an accelerator was used to hasten mortar setting.
Was the method successful? Masons had no complaints about the working environment, and they were happy to have winter work, says the Salvucci firm. Courtesy SCPI
Estimating Formula for BTU Volume
Cubic Feet to be Heated X # Temp. Rise X 140 BTU for 1°F. Rise 1,000 Cu. Ft.
EXAMPLE: With the temperature outside 20° you want to maintain 40°F. having 50,000 cu. ft. to heat.
140 50,000 x 40°-20° x 1,000 = X BTU
50 x 20 x 140 = 140,000 BTU
Factors not considered are the type of insulation or covering used and the wind velocity.
masonry October, 1969