1960 prestressed concrete roof
1960 prestressed concrete roof
(OP)
I am wanting to add a second floor condo to a commerical building built in 1960 located in the panhandle of florida. Its 26 foot wide and 50 foot long and there are 40 prestressed concrete beams measuring 15"wide x 9"thick and 26 foot long. The building walls are block construction 12 feet in height. There are no interior supports the building is a clear span. I need to determine if this roof structure can support a single story wooden structure.






RE: 1960 prestressed concrete roof
RE: 1960 prestressed concrete roof
It was a very good product and especially economical in the 25 to 30' span with practical maximum of 30' (60' total bed length).
Many homes, motels and small commercial buildings were built using this since above the basement since it had a maximum span of 30 feet and a first and second floor could be built above the plank over the basement. - A 30' x 50' basement with no columns. The erection cost was low because of the plank weight (small mobile cranes) and ability to place/move it accurately. The accurate, large formed (not extruded) cores were frequently used for HVAC distribution
If this is the product you have, this may give you information to a possible supplier. The licensing company was based in Ohio, if I am not mistaken. Many of the producers of this product ultimately went to wider plank because of the lure of tilt up and large projects.
The supplier (usually within 200 miles) may have the old information on the product supplied because the the record keeping required by the franchiser.
RE: 1960 prestressed concrete roof
Our precast firm has original drawings & engineering files dating back to the early 1960's. I just recently pulled out an engineering file & shop drawings for a local apartment built in 1975, when I was still crawling around in diapers!
RE: 1960 prestressed concrete roof
Mike McCann
McCann Engineering
RE: 1960 prestressed concrete roof
thanks fishhawk