Lime plastered clunch walls

[leah87]

Hello,

I've just had my Victorian Clunch cottage rendered and plastered in lime putty.
Because the lounge is north facing and over the years the door way and windows have been moved; its now quite a dark room. So I wanted to hang mirrors on the walls to try and brighten the space up a bit.

Obviously I don't want to damage the new plaster as its cost a small fortune, but it seems incredibly hard now it has dried. I don't want to go nuts or anything but mirrors can weigh 15-20kg and I'm after reassurance that the walls wont crack if I were to drill small fixings into them.
There is the added issue of the walls beneath being clunch which is very soft. Does anyone have any experience with this?

Thanks in advance!

 

[livias]

I wouldnt use small fixings, that seems like a lot of weight on a tiny point

Traditionally you would fit a wedge of wood and fix to that. It seems to have gone out of fashion as a technique but I don't know why because when I come across such wedges they are generally well wedged. Drill a nice deep 25mm hole. Cut a wooden wedge which tapers 20mm to oooh 28mm and is 80mm long. Put some polyfilla or similar in the hole and then tap the wedge gently in. Tidy up the dribbles, allow to set, touch up with paint if necessary and use it as your mirror fixing

 

[Flyfisher]

I agree about avoiding small fixings. Heavy objects generally need deep secure fixings so that the fixings don't move, which is the thing that leads to cracks. If possible use more than one fixing to spread the load. For heavy items I'd use something like these:
http://www.screwfix.com/p/slotted-mirror-plates-electro-brass-32-x-32-x-32mm-10-pack/14738

Such fixings provide a very solid and rigid mounting though they remain visible, which some people don't like.

 

[leah87]

That's very useful advice! Thank you!