Chipping out post-tension slabs

[jar546]

I am starting to see a lot of post-tension slabs being chipped out in order to be able to get the LED drivers in and out for these ceiling high-hats. I now have to be pro-active as many are furring out the ceilings to get the high-hats in. Thoughts? Would you allow this on a post tension slab?

 

[RLGA]

Only if the structural engineer has said it is acceptable.

 

[e hilton]

I would think if they used a gpr scan first it would be ok.

 

[ICE]

Only if the structural engineer has said it is acceptable.

I don't think so.

 

[RLGA]

I don't think so.

Cutting into PT slabs and floors happen all the time. As e hilton stated, you need to have ground penetrating radar to determine where the cables are (and any other embedded items such as conduit) before drilling or cutting. No drilling or cutting can happen unless the structural engineer has reviewed the work, done the calculations, and given his/her approval.

 

[ICE]

I think I’d talk them into a lamp instead.

 

[ICE]

Does ground penetrating radar perform better than X-ray?

 

[RLGA]

Does ground penetrating radar perform better than X-ray?

Yes, and much quicker.

 

[ICE]

I learned something new today.

 

[RLGA]

I learned something new today.

Here’s some more information about the comparison: https://masterlocators.com/about/news/ground-penetrating-radar-gpr-vs-concrete-x-ray

 

[ICE]

I have no experience with GPR or x-ray. Using the example of a retaining wall I wonder if the GPR works for that and how detailed it will be. Can the size of rebar be determined?

 

[ADAguy]

Ice, technology is a wonderful thing up to a point. Have you used drones yet? Now think of LIDAR?

 

[e hilton]

The advantage to gpr is that it does not require “film” on the other side to catch the xrays.