Hollow core precast panel manufacturer help

[jplay2519]

I'm trying to find some information on the manufacturer of this panel type. I'm going to the site to document next week I believe but wondered if anyone had an idea just based on the type of leave in forms they used and the rectangular shape. I should have dimensions to help if that's needed after the site visit. HVAC guy cut the roof open then felt uncomfortable to put the curb and unit in because he saw the cut strands and told the owner to call a structural engineer. Thanks for any tips. (Edit: I tried to post multiple pictures but it only let me do one, I don't want to spam post with like 5 posts to get the photos in but can add some once I get any replies requesting more photos I guess)

 

[GC_Hopi]

Hollow core are manufacturer dependent. Where is the job located? Try calling some local company...

 

[Rabbit12]

Lol. Classic. Cut hole in concrete roof without consulting a structural engineer. Now you get asked to bless their lack of planning.

 

[DayRooster]

I have done a fair amount with precast planks and cutting strands is a problem. Openings that big typically only work if the hollowcore planks were originally designed with that large of an opening in mind. I would be amazed if this works without a fair amount of additional structure added to it.

Personally I would not take the work since I image the reward is low for this small task and the risk is high. Also I imagine the client has no perception of the scale of the fix if they allowed for the HVAC vendor to get this far without structural approval.

If it helps too, I have always directed the work straight to local precast firm (hopefully one of the did the original project and is willing to take the work). Precast firms are bettered prepared for these types of unique situations. But if you do decide to venture down this path then best of luck. And let us know how it all turns out. Curious to see what the end result looks like for this one.

 

[jplay2519]

Thanks for the responses. It's in Atlanta, GA. There are a few pre-cast manufacturers here that I could contact. I tend to agree with DayRooster, decline the work and push it to a precast manufacturer. Owners rarely understand how complicated it can be to do "simple" things like cutting a "small" hole in a member. I mean whether it's plywood, steel, concrete there are so many things I've seen done and then the solution is so complex because the building just was not meant to be modified in such a a way. The fees get out of hand because it takes a while to figure how it will work (or you just undershoot it because you don't realize it's that complex), the repairs get expensive, and it's all the engineer's "fault".
I hate to leave clients dry but I've been burned quite a few times trying to help when I know that it's going to turn into something they aren't prepared for (yes I do try client education as my therapist suggested but we all know that you can only explain so much when it comes to certain people's money).

 

[dhengr]

Jplay2519:
This particular work was not in your contract, and they didn’t bother to come to you or the precast supplier before they cut the hole. You asked several times while you were designed the roof system if they had given you all the Mech. weights, sizes and deck hole sizes so you could finalize your design. The HVAC guy made the mess, he cut the small hole (small by who’s definition?), so let him get his own Structural Engineer to sign off on it, and tell the owner that it is o.k. That way, the time and cost falls where it belongs, and not on you. If the client doesn’t generally understand your stance, then maybe he’s not that good a client afterall. I always try to be helpful to clients too, but just because I got underpaid for a job I did for them some years ago, doesn’t mean that I have to work for nothing, cleaning up all their future messes.