Hanging a heavy mirror – what length screws

Hi all, wondering someone can help ‘a friend’ with limited DIY skills, before I (err… I mean they) drop a mirror on the dog.

Have a 20kg mirror with two hanging loops attached. I’ve bought two j-hooks each of which has holes for two screws. The wall is external (it’s an 80s house so probably plaster on breeze blocks).

What length of screws would you use? The holes in the j-hooks suggest gauge 8 screws. Are 1.25 or 1.5inch long enough or should I go with something closer to 2inch? Am a little concerned that by the time you’ve got through the plaster there’s only going to be a small amount of screw in the block.

Thanks. 🙂

Between plasterboard and dot’n’dab, you’ll have an inch-ish of screw alone in that, so you want to be going something like 80-100mm in red plugs. If it’s breeze block, an ordinary drill with 6mm masonry bit should do that fine. Wrap a piece of masking tape around the drill at the screw length as a marker.

I’ve just hung a solid oak mirror (~15kg) with a single number 6 and a rawl plug, the screw was about 2 inch long. It’s not going anywhere in a hurry.

What length of screws would you use? The holes in the j-hooks suggest gauge 8 screws. Are 1.25 or 1.5inch long enough or should I go with something closer to 2inch? Am a little concerned that by the time you’ve got through the plaster there’s only going to be a small amount of screw in the block.

If it looks like an 8 gauge, you’ll be able to put at least a 10 thru easily, and force a 12.

I usually work on the theory that it’s best to put a longer screw in than a shorter one. Also use decent rawl plugs.

Remember the pull is only acting downwards when hanging a mirror. Not like a deep cupboard when the pull on the top screws is pulling away from the wall. That’s when you need the long screws and rawlplugs.

Ok, thanks for the help everyone. Sounds like the 1.5’s will be fine, but I can reasonably increase the screw gauge to 10.

Is odd… lower leg services, pressing my own headset or BB bearings I can cope with. But crumbly walls scare the bejesus out of me!

I recently replaced my mirror hooks – I went for some of the 135mm x 10mm plug and screw setups from Screwfix (usualy used to fasten window and door frames to blockwork).

I found a void behind the plasterboard so even with 2″ of thread on the hook I couldn’t be confident that the plug was actually fastened into anything. It now feels absolutelly bombproof. I’ve been confident enough to add some spacer blocks to the back of the mirror to angle it down a little 🙂

The best way would be to mark and drill your holes, see how much ‘solid’ wall you have then size accordingly, a metric 4×40/50 in red plugs should be fine I’d have thought unless you’ve have an inch of knackered plaster in the way 1st, be aware you may find the joint rather than brick when drilling.

As mentioned above the mirror won’t be trying to rip the fixings out as it’s trying to slide down the wall not lever out.

I’ll echo the advice on using good quality fixings. Anything that comes with rawlplugs, bin them and use your own ones.