Mounting projector on a board into joists

[freddiemercurystwin]

Adding a noggin above is better than all this as mentioned already, it's not difficult unless the floor above is inaccessible or laminated or similar.

 

[sunshinewelly]

Hi floor above is laminated

Is this stuff strong enough to attach to ceiling and hold a 17kg projector. Its only 16 mm thick though

 

[motorbiking]

i’d be tempted to use grip fix as well as screws. That’s how i did mine. I just painted the marine ply white to match the ceiling and put as many screws in as i could within reason.

 

[ray.birch]

I would definitely use ply and not shelf board - some of those boards can be of dubious quality.