This is an image showing how precast panels are propped
Propping parameters
Usually propped at 2/3rd height.
No of props usually 2
if the panels are wide could go to more than 2. But rarely 4.
For Panels which span 2 floors, There could be 4 props. 2 below the floor above and 2 above. When you have such a case you have to show opening on the slab through which the upper props will pass.
How long will the props stay in place.
Usually between 1 to 2 months. It could be longer if the construction pace is slow.
How many props are usually used in a multi storied construction?
Depends on construction speed number of panels.
But the number could be around 200.
With prop hire rate of around $3 per week, you can see that the cost of propping is not very small.
When you are estimating for precast, it may be good to consider how many props will be used and what would the cost of propping for a project
Propping is highly skilled job. Improper prop installation can cause accidents shutting down sites, sending stake holders broke. Not to speak of the harm it does to the site personnel.
Who designs the prop.
Most of the the time props are drafted by the detailer and submitted for approval to the engineer.
Detailer cannot issue panel or propping drawings unless there is an approval from the engineer. The certification from the engineer is a must. Without that shop drawings cannot go for construciton.
Without certification, the propping is no go good, illegal and not fit for purpose.
Insurance companies will not cover if there any issue because of prop failure if the drawings were not certified by a qualified engineer.
