Mounting projector on a board into joists

[sunshinewelly]

I have a 15kg projector with a mount. The place I need to attach it to ceiling is smack between 2 joists. The projector plate which ideally should be at attached to joints in 2 places has 4 holes depending on which way joist runs. Now as I can't get the ceiling mount at a joist I was thinking of attaching a board with a number of wood screws to the 2 joists. My question is will a board take 17kg of weight or will the projector just rip the screws out of wooden board. My other thought was to use bolts and bolt plate to board so that the plate can then not be ripped out of board. Only problem with that method is that the tops of bolts will be forced into ceiling when I attach board unless I use some spacers

 

[foxhole]

Properly secured a joist will take your weight hanging from it. Though at 15kg it must be very old projector, you can get one weighing less than 15 ounces cheaply and probably far superior in quality.

 

[sunshinewelly]

I was not looking at a review of my projector. It's heavy as it's a very new 4k state of the art projector. I am also aware a joist will take the weight. I want to know if a piece of board would hold that weight. The thinner the board the better etc

 

[rsgaz]

I want to know if a piece of board would hold that weight. The thinner the board the better etc

A single number 10 woodscrew will hold 39KG in a half inch (12.7mm) plywood board. (i.e. 173lbs ÷ 2)

From the 'American Wood Council'...

So, in other words, don't panic. If you want to go really overboard, then use threaded inserts in the 'top' side of the board you are attaching...

https://www.ebay.co.uk/itm/302519352530

...or 'T nuts'...

http://www.ebay.co.uk/itm/181230569842

...with bolts and washers from underneath in either case.

 

[sunshinewelly]

Cheers for that response. With the threaded inserts I assume I drill a guide hole through the whole of board and then a slightly bigger on the other side of board to fit the thread and then once thread is in place screw through board and into the thread cap.

When you refer to bolts and washers I am slightly confused over what you mean. The plate I attach to board is metal with 4 holes. So I understand to use a washer with a screw through plate but where do bolts come into in. Sorry for my ignorance on this

 

[foxhole]

I was not looking at a review of my projector. It's heavy as it's a very new 4k state of the art projector. I am also aware a joist will take the weight. I want to know if a piece of board would hold that weight. The thinner the board the better etc

You provided no details of the board?
PLY, chipboard, mdf etc?

 

[sunshinewelly]

I am not sure what would be the best board to use. Looking for the one that will offer the most resistance to a weight hanging from a screw. Cheers

 

[foxhole]

Probably ply .

 

[sunshinewelly]

Thankyou for the help

 

[Tigercubrider]

I would use ply, adding T Nuts to the back, and screwing the board to the ceiling joists.
https://www.screwfix.com/c/screws-nails-fixings/pronged-tee-nuts/cat7280112

this allows the whole bracket to be bolted to the ply and removed/replaced.

 

[rsgaz]

So I understand to use a washer with a screw through plate but where do bolts come into in.

They're only if you choose to use the threaded inserts or T nuts, rather than just short but wide normal screws straight into the board.
The threaded inserts have a metric screw thread on the inside, you don't screw normal wood screws into them, you use short bolts.

 

[sunshinewelly]

Cheers. I think I now understand. So basically I get a set of matching M size bolts. Drill corresponding sized holes through the board. Hammer in the t nuts through holes. Attach board to joists then attach mount to board

Is there any benefit in using hardwood or softwood plywood.

 

[Ian H]

If you could get access above you could fit some Noggins between the joists and attach to those, that way you would have no unsightly board.

 

[Tigercubrider]

I would use hardwood, although it may not matter.
Not so much "hammer" as they are better drawn in, use a hammer to tap them as a start, and then use a washer and bolt to draw the T nut into the wood. It will be neater. Then undo the bolt and do the others. Check alignment, then paint/fix to ceiling.
Mount bracket.

 

[sunshinewelly]

Do I need to route a shallow hole in the board. Just thinking that the board will not be flush with the top of the t pins