Help with "suspended concrete" ceiling

[LarryFine]

Hey, gang. I got a job to install six recessed lights in the library of a church. Yesterday, I removed an existing square light to see what was above it. Instead of the textured popcorn being on drywall, it appears to be on about an inch of concrete. There are steel bar joists about every 44 inches, with perpendicular square rods about every 12-14 inches.

Wire wraps around them that seems to be imbedded in the concrete. My guess is that a mesh was sprayed or otherwise applied to it that resembles concrete.
Anyone have experience with this type of ceiling?

The question is whether a typical 6-3/8" recessed-light hole-saw will cut through it, or do we need to explore alternatives, such as a shallow surface-mounted flush-type LED light, like a Versi-light? Examples:

https://www.homedepot.com/p/Lithoni...tegrated-LED-Flushmount-FMML-13-840/206339163

https://www.homedepot.com/p/Lithoni...ntegrated-LED-Flushmount-FMML-7-840/203583417

 

[hbiss]

Stucco. It is concrete so don't expect to get anywhere with a regular hole saw. They do make abrasive carbide and (preferably) diamond. But if you can sell them on those surface mounted fixtures that would be the way to go, and a lot cheaper.

-Hal

 

[ActionDave]

I agree with Hal.

 

[gadfly56]

Does the mesh look like expanded diamond mesh?



Full system:

 

[LarryFine]

Does the mesh look like expanded diamond mesh?

I don't know, as it's not exposed, but the parts I can see do look like the past pic.

We're now on hold as they want to explore options, such as brighter bulbs in the existing lights.

Related question: if they cancel the contract, am I entitled to bill for the time spent in exploration?

 

[Little Bill]

I don't know, as it's not exposed, but the parts I can see do look like the past pic.

We're now on hold as they want to explore options, such as brighter bulbs in the existing lights.

Related question: if they cancel the contract, am I entitled to bill for the time spent in exploration?

I would think at least a service call rate would be appropriate. Depending of course on how the contract is written and how much time you spent.

 

[LarryFine]

I spent about 2.5 hours in total, the removal of one cemented-in existing 10"-square recessed light for my head and a flashlight to gain visual access being the majority of the time. Then there was opening another light and the switch, so I could explore the use of the existing conduit between that light and the existing switch, for the purpose of adding a second switch to the switch's 4" box w/ 1-gang plaster ring.

Also, there was a trip to the store to see whether I could find anything with which to make a 6.25" hole in the stucco (there wasn't). Let's not forget wiping down the tables and chairs, and vacuuming the carpet after putting everything back together. And pulling out and putting away the 10' ladder.

See: http://forums.mikeholt.com/showthread.php?t=189126
'

 

[JoeyD74]

I spent about 2.5 hours in total, the removal of one cemented-in existing 10"-square recessed light for my head and a flashlight to gain visual access being the majority of the time. Then there was opening another light and the switch, so I could explore the use of the existing conduit between that light and the existing switch, for the purpose of adding a second switch to the switch's 4" box w/ 1-gang plaster ring.

Also, there was a trip to the store to see whether I could find anything with which to make a 6.25" hole in the stucco (there wasn't). Let's not forget wiping down the tables and chairs, and vacuuming the carpet after putting everything back together. And pulling out and putting away the 10' ladder.

See: http://forums.mikeholt.com/showthread.php?t=189126
'

Did you look at the job before you quoted it?

 

[LarryFine]

Did you look at the job before you quoted it?

Yes, including going into the "attic" with the floor covered in insulation, but I thought it was a wood floor. I didn't realize that the attic floor was originally a flat exterior roof and merely covered by a new angled roof with HVAC equipment in it. Nor did I take the light out of the ceiling. To me, that was part of the work of the contract which I had not yet been awarded.