Sorry tumpang thread TS.. May I know what is the minimum clearance you need between the plaster ceiling and anything above it like floor slab or beam?

After planning my lighting, I only found out that two of my light position is right under a beam. My initial plan was to put plaster ceiling at beam level, However, now I think i need to lower the plaster ceiling some more to accommodate the downlight. Question is, by how much?

Thank you for you answer. I saw in the leaflet for marcasite the height is 2.9cm. But on top of the 2.9 cm, how much extra allowances do we need to allocate? What about distance from beam from the side, if any?

And in the leaflet also there is "recessed distance" specification which is 5cm. What is that actually?

My floor to ceiling height I measured is 10ft and 4 inches, the beam is 14 inches and almost 1ft wide (I forgot to measure, it definitely looks wider than the normal 6 inches beam. If I level the plaster ceiling with the beam, net remaining height would be around 9ft 2 inches. How much lower should I go to install downlight directly under the beam? I will be installing ceiling fan as well, so I can't go too low.

And another restriction is that I want my ceiling to be flat. So, having different level of ceiling fan and downlight is not really preferable.

Thanks.

Since there is option as slim as 29mm, I might be able take 2" off my ceiling height and make it 9' to fit the downlight if I can't find a way to rearrange my lighting position. The problem is that my living & dining hall are pretty short, so, I need to be precise to divide the two area so that I would not look so cramp, hence why I need to do a careful planning on the downlight positions.

I managed to find few options of ceiling fan with shorter than normal pipe length. So, that one pretty much solve my concern of having fan that is too low.