ᐅ Retrofitting LED spotlights into a precast concrete ceiling

Hello everyone,

Our planned precast concrete ceiling will be installed soon. We have already been considering the positioning of the lights in advance.
We would like to install individual LED downlights into the ceiling without lowering it.
I have already seen that recessed housings for LED spotlights are available (including from Kaiser).
Is it possible, once the precast concrete ceiling is in place but before the additional layer of concrete is poured, to create the openings for the LED downlights on site? I understand that the required diameter for the LED spots is relatively large and that this might be challenging with a reinforced concrete ceiling.
Please share your experiences.

Yes, it is certainly not recommended, and depending on who is building your house, it could cause issues with the warranty, but it is possible. However, it is especially concerning in areas like stairwells.

In our case, I have also drilled a few holes here and there that were either forgotten during planning or decided on-site that something needed to be installed there.

Yes, that’s possible. You’ll need a core drilling machine and enough time depending on the number of spots.

Prepare the necessary measurements. When you’re on the ceiling, you have no way to orient yourself to find the drilling point. Maybe drill through from below with a rotary hammer and then use the core drill from above.

guckuck2 schrieb:

Yes, that works. You’ll need a core drilling machine and, depending on the number of spotlights, the appropriate amount of time.
Prepare the necessary measurements. When you’re standing on the ceiling, you have no reference to locate the drilling point. Maybe drill through from below with a rotary hammer and then use the core drill from above.

That’s how I was thinking as well. Which recessed light housings would you recommend for this? Kaiser distinguishes between in-situ concrete and precast versions. Which product should I use in my case?

Kaiser 1290-30

danixf schrieb:

Kaiser 1290-30

Thank you for your message. Is it possible to plan for an electronic ballast (EVG) inside the junction box?
I noticed that Spelsberg offers such built-in boxes.

What would be the advantage of this?

//Edit:
I read that these boxes (Kaiser 1290-30) are designed for installation in solid concrete slabs. Currently, we only have the prefabricated ceiling slab. The concrete will be poured later, after the cables have been installed. Is this still the right product in this case?