Hanging heavy mirror

[Thomasom]

Hey.
I'd like to hang a heavy mirror in my living room.
It's to go on block wall with plasterboard. It's a fairly heavy bit of kit (18kg) and would be in an area where my children play so need it to be SOLID!

The mirror has a keyhole bracket on each side, whilst sitting on top of a mantlepiece. (Only an electric fire)

What would be the minimum size/best screws to fix it to wall?
Thank you!

 

[freddiemercurystwin]

Plugs and screws, I would go for something say 60mm deep with as big a screw (head) that will fit in the keyhole.

 

[Thomasom]

Thanks for the response. I have these, which are 70mm. Should be enough do you think?

 

[JohnD]

You must of course screw into the blocks by about 35mm

Ignore the plasterboard and the air gap

 

[Thomasom]

Should I be looking at 80mm+ screws then?

 

[JohnD]

Depends how far away the blocks are.

 

[Thomasom]

Right, thanks. How do I know this?

 

[freddiemercurystwin]

Drill a small exploratory hole, that should enable you to measure the distance from the outer face of the plasterboard to the face of the blockwork, add about 50mm onto that dimension and you've got your screw length.

 

[foxhole]

Unless it’s thermalite blocks.?

 

[Thomasom]

Ok, there is a chance that this is breeze-block chimney breast.
How does this change things?

Thanks!

 

[foxhole]

Ok, there is a chance that this is breeze-block chimney breast.
How does this change things?

Thanks!

Breeze blocks ok but thermalite doesn’t take standard plugs , if you can force a screwdriver into wall by hand it’s thermalite .

 

[mrrusty]

In fact, you don't need to worry about the blocks - screws and plugs are fine, but with a mirror all the force is idownwards with the fixing in shear and virtually zero is tension (i.e. trying to pull out). You could just use a decent plasterboard wing fixing like https://www.screwfix.com/p/gripit-plasterboard-curtain-fixings-kit-15mm-x-95mm-6-pack/844HT?kpid=844HT&cm_mmc=Google-_-Datafeed-_-Screws, Nails and Fixings?kpid=KINASEKPID&cm_mmc=Google-_-TOKEN1-_-TOKEN2&gad_source=1&gclid=CjwKCAiAloavBhBOEiwAbtAJO-KXg5iOfqygCZCMn6FnuhgDvs7JEnVz-LBbOIKR9x6v-jhz404LThoCxiQQAvD_BwE&gclsrc=aw.ds

note the max load - 71kg!!

As the shear strength of PB is high, for pictures and mirrors with only shear forces involved, personally I would just use a thorsman TP2 red plug and allow the wings to expand in to the gap behind the PB. Not had one pull out yet.....