Hanging a very heavy mirror in a chimney stack.

[Jane Doe]

Hi, quite newb here and need some advice. I have a 15kg mirror (it's oak, it's big!) I want to hang in the bedroom. It already has D-rings on it so I just need to put in something to hang it from. I'm 90% certain it's too heavy for regular 'tap in a nail' picture hooks.

My house is a 1920's terrace, single fireplace with a chimney stack (about 125cm wide) that runs up through my bedroom. Everything is painted and decorated and I don't remember what it looked like underneath well enough to trust it. I've tapped back and forth across the chimney stack and it sounds hollow towards the outer edges but less hollow in the middle two quarters. And that goes all the way across the middle, not just starts, stops and starts again. I'm not certain that it's brick though. It might just sound less hollow because it's closer to or up against the brick. (Wild guess - don't know). I drilled into it with a very widdle drill bit, around the centre of the stack. It was briefly hard but then very soft (no comment!) so I went through 'something'. The drill bit was only around an inch so I didn't go very deep. Fine, greyish powder came out - Could be brick dust or plaster or out of date cocaine for all I know - I truly have no idea, but it was quite fine.

So I don't know if this is brick, plasterboard, dry wall and whether I need rawplugs and screws, "wall-anchors" or those-spring loaded things. I'm also worried if it is plasterboard, whether that's strong enough to support a 15kg mirror. I do not want to see half my wall pulling away!

Tried to give as much information as I could think of. ANY help is appreciated.

 

[blup]

Sounds as if the original chimney opening has been filled in with concrete blocks and plasterboard dotted and dabbed on top. That would suggest a conventional screw and plug fixing into the block

If its plasterboard, metal cavity fixings will take the weight of the picture, but requires a gap behind the board to "spread" the wings that grip

Grey dust suggests concrete block behind the plasterboard but it might be the dust from the plasterboard.

Can you drill deeper as you will need at least a 2" screw.

Blup

 

[Jane Doe]

Sounds as if the original chimney opening has been filled in with concrete blocks and plasterboard dotted and dabbed on top. That would suggest a conventional screw and plug fixing into the block

If its plasterboard, metal cavity fixings will take the weight of the picture, but requires a gap behind the board to "spread" the wings that grip

Grey dust suggests concrete block behind the plasterboard but it might be the dust from the plasterboard.

Can you drill deeper as you will need at least a 2" screw.

Blup

Thanks!

The chimney is actually open. In that it's covered up at the fireplace but the stack is definitely not blocked and one day I might like to put in a small stove. But having just typed that I realise you probably mean the fireplace opening in the bedroom? I have no idea, there's a radiator over where the fireplace would be if there ever was one. I'm hanging the mirror about 6' up though so above there anyway. Does this make a difference?

I can drill deeper, but the only drill bits I have that are long enough to do 2" are also wider so I want to be more certain I'm doing it right. I have a 5mm bit that is 2". If I drill where I want the first fixing with that it's not going to matter whether it turns out to be pasterboard or not, then? I do that and if it's plasterboard I go and get cavity fixings and if it's brick, I just put raw plug and screw in there?

 

[blup]

Drilling with the longer bit as you suggest will assist in identifying the material behind the plaster, and what if any voids exist.

A drawing pin will identify the difference between plasterboard and plaster, the latter will resist the pin when pushed in.

Blup

 

[Jane Doe]

Drilling with the longer bit as you suggest will assist in identifying the material behind the plaster, and what if any voids exist.

A drawing pin will identify the difference between plasterboard and plaster, the latter will resist the pin when pushed in.

Blup

I wasn't able to push a drawing pin in at all - just a small dent in the paint / lining paper. So this means it is plaster over brick and I should be putting in rawlplug and screw, then? Any advice on what depth and diameter I should look at for a 15kg mirror?

 

[blup]

I used a Spax 60mm woodscrew 5mm (no 10 in imperial) and a Fischer nylon plug. You can use two plugs if the hole is deep enough by snipping off the rim and base of one of the plugs - not essential but gives greater grip. If I recall correctly the hole drilled is 8mm

That’s what I used when I hung a similar sized mirror, coincidentally over a fire place

Blup

 

[Jane Doe]

I used a Spax 60mm woodscrew 5mm (no 10 in imperial) and a Fischer nylon plug. You can use two plugs if the hole is deep enough by snipping off the rim and base of one of the plugs - not essential but gives greater grip. If I recall correctly the hole drilled is 8mm

That’s what I used when I hung a similar sized mirror, coincidentally over a fire place

Blup

I drilled a little deeper where I want to place a screw and hit something impenetrable. About 1cm deep. Metal stud?

 

[blup]

It could be a number of things, can you post a picture of the fireplace/flue from inside the room?

Blup

 

[Jane Doe]

It could be a number of things, can you post a picture of the fireplace/flue from inside the room?

Blup

I'll take a photograph in the morning. But there's really nothing to see. It's just an expanse of wall 1.25m wide projecting about 30cm into the room in the centre of one wall. It is uniform from floor to ceiling. It was covered over with lining paper and then painted over. It's coming back to me now. I remember underneath it was just smooth, white surface that we sanded down a little to make smooth before decorating.

 

[blup]

If it's the original fireplace then it's difficult to see what metallic structure would be in there. I was thinking maybe the chimney breast had been removed and replaced with a gallows bracket to support an upstairs flue, or possibly some kind of metal studwork.

1920's brick would be incredibly hard and might feel impenetrable especially if the incorrect, or a blunt, masonry/concrete bit is being used; or if the percussion setting of the drill you are using is no longer up to the job.

I assume there are no pipes or cables buried - unlikely perhaps given the location and the depth you refer to.

The alternative is to provide two off centre fixing points, this will also help spread the weight of the mirror, and you can locate a point that is more receptive to drilling.

Blup

 

[Jane Doe]

1920's brick would be incredibly hard and might feel impenetrable especially if the incorrect, or a blunt, masonry/concrete bit is being used; or if the percussion setting of the drill you are using is no longer up to the job.

This was it. It's actually quite a good drill but I had it dialled right down low, not on hammer mode and *ahem* the drill bit not very well tightened. These things attended to, it went in fine. Red brick dust coming out now. I've gone in around 1". So your suggestion for a 15kg mirror is 60mm length screws, 5mm width, in a plastic rawlplug? Just to be sure. I plan to make two holes, evenly spaced and hang it from both. That'll spread the load a bit more and let me move it slightly from side to side if my holes aren't perfect.

I saw these when I was watching videos on hanging heavy objects. Would these be better?

https://www.screwfix.com/p/rawlplug-rawlbolts-m6-x-70mm-5-pack/60234

Loads of thanks!

 

[opps]

Rawlbolts work by pulling the "cone" at the far end. The process results in expansion which wedges the fitting in the hole.

In your case you won't be fully tightening the bolt, so no they wont work.

Personally I use coach screws with washers heads. I like to think that the washer head reduces the risk of someone accidentally lifitng one corner of the mirror and making it fall off the fitting. I also believe that the shear load of a coach screw is greater.

https://www.screwfix.com/p/turbocoach-coach-screws-yellow-zinc-plated-8-x-70mm-50-pack/38295

and

https://www.screwfix.com/p/fruilsider-nylon-wall-plugs-10-x-50mm-50-pack/3473t

You will however need a 10mm drill bit.

 

[blup]

A rawlplug, yes, with a woodscrew (not a rawlbolt) should be fine but don't buy cheap, the heads shear off the cheap woodscrews, which is why I mentioned Spax but many other good brands are available if you look on Screwfix.

Hope it all goes to plan.

Blup

 

[Jane Doe]

Rawlbolts work by pulling the "cone" at the far end. The process results in expansion which wedges the fitting in the hole.

In your case you won't be fully tightening the bolt, so no they wont work.

Personally I use coach screws with washers heads. I like to think that the washer head reduces the risk of someone accidentally lifitng one corner of the mirror and making it fall off the fitting. I also believe that the shear load of a coach screw is greater.

https://www.screwfix.com/p/turbocoach-coach-screws-yellow-zinc-plated-8-x-70mm-50-pack/38295

and

https://www.screwfix.com/p/fruilsider-nylon-wall-plugs-10-x-50mm-50-pack/3473t

You will however need a 10mm drill bit.

A rawlplug, yes, with a woodscrew (not a rawlbolt) should be fine but don't buy cheap, the heads shear off the cheap woodscrews, which is why I mentioned Spax but many other good brands are available if you look on Screwfix.

Hope it all goes to plan.

Blup

Thanks both. I've picked up a 10mm masonry bit this morning and I got the coaching screws and plugs you linked to Opps. They didn't have Spax so I just went with the ones you linked. I got some washers as well to make it even harder for the chain to slip off. The only problem with the coaching screws is that they have a very long smooth part to stick out. I'd prefer it was just 15mm or something rather than around 30+mm, but I couldn't find any like that. They seem standardised that way.

Well I'm off to drill some holes now.

 

[opps]

Hi Jane.

I understand your point about the length of thread. Assuming that the coach screws are sitting proud of the wall by about 10mm, you still have 30mm of thread running through the end of the wall plug. The length of protruding screw will determine how much of yourself you can see when standing in front of the mirror.

It would only be an issue of the plug was so short that you ran out of thread before the screw had "driven home". The absence of thread would mean that the screw would not pull itself into the wall and it would just spin as you tried to tighten it.

I haven't used those particular coach screws, unless they have a Phillips or pozidrive slot in the hexagonal head, you may want to purchase a magnetic hexagonal adaptor for your screwdriver. That said, you are only using two coach screws so using an adjustable spanner isn't too much of a chore and the fixed washer will prevent the spanner constantly slipping past the head and down the shaft.

If you do decide to use additional washers, make sure they aren't too big, otherwise it will be difficult to fit the D over them. I'd also recommend using masking tap or blue tack to stop them sliding back towards the wall as you tried to fit the D over them.

I have no idea if you are using a hammer drill or an SDS drill. If the former, I strongly recommend that you use a smaller diameter drill bit first and then the 10mm bit. If you find that the holes deviate out of alignment by a couple of mm, you should be able to hammer the coach bolts slightly to bend them to "your will".

Oh and if you have a helper, get them to hold the vacuum cleaner hose close to where you are drilling.

Best of luck