Hi all,
I have to mount a few air temperature sensors for the heating system and my weather station on the North facing external wall - the wall was previously plain brick but it has now been insulated externally with
90mm EPS board and finished with a lightweight render.Is there anything I should watch out for when mounting the sensors? Also, it is likely that we will be fitting a security light to the wall too so is there anything special needed to mount the lights on an insulated wall?
Much depends on how strong the render is...
Is there a test I can do? Perhaps involving an angle grinder? :-)
In my domestic aerial installing days I learnt that fixing cables to render of the sort done by cowboy builders on recently purchased ex-council houses was a bit of a problem. Sometimes a tap with the hammer would result in a resonance that told me that the whole area of render had detached from the wall. A serious attempt to knock in a cable clip might result in area of render a yard by a yard falling onto the pavement.
Bill
Other than trying a fixing just into the render in a discrete place, not really.
The other option is to go for the 5" screw and drill right through the insulation and into the original brickwork. Then put a plug on the end of the screw and tap it through the render and the insulation and into the wall, before tightening the screw. Take care not to over tighten.
So you end up with a screw that goes into brick by only about an inch, with
3-4" of shaft running through the EPS & render, then the item you're hanging on the wall attached at the outer end of the virtual lever. Wouldn't it tend to flap around a bit?Small items being hung will probably only have small mounting holes, but this 5-6" screw is likely to be a #8 or #10, which might present a problem.
If the render is reasonably strong, could one glue/mastic some sort of board onto it?
I wonder if there are fixings, a bit like those used for hollow doors, that one could use that would pierce the render and a little of the EPS behind, then spread out to grip the EPS?
I think I'd be inclined to try to fit a wooden batten/spreader onto the wall, then mount objects on that. Drawback with a batten/spreader will be rot, and fixing a new one in due course might be tricky, especially if you tried to use the old screw holes/plugs.
If I needed the mount to be able to take a reasonable weight I don't see any reliable method other than piercing the render and removing a core of EPS, then filling that void with a 3-4" deep wooden plug or something screwed firmly into the brick, then one could scrrew the item onto the plug.
Perhaps the OP should ask the insulating company? They'll know if there's a reliable method. I suspect they'll say such mounts should have been planned before the wall was insulated.
Depends on how thick the EPS. If its 2", then you get a couple of inches of screw in the wall, and the render provides some lateral restraint - which is probably its strongest mode.
Indeed. Only really suitable for bigger stuff. Small stuff you should be able to get away with fixing just to the render unless its very thin or weak.
The hollow wall anchors with a setting tool might work - the EPS is probably soft enough to allow the back of the fixing to spread when you set it.
One assumes that there was some form of (metal?) mesh support fixed over the EPS board to provide some form support/key for the render? And that this mesh was fixed to a frame work of some sort fixed through the insulation to the original brick wall. If so a suitable depth hollow wall anchor that spreads onto the back of the render/mesh will probably do for sensors and small things.
What do you mean by "weather station"? A 10 m long ali scaff pole to support and anemometer/wind vane or something a bit smaller?
OP said 90mm...
I will have to ask someone who was home when the rendering was completed, I was not at home.
No it's just something similar to this:
He did yes, sorry misread that.
Some of the light weight systems can go straight onto a glass mesh that is bonded to one side of the EPS... cheaper than needing loads of expanded metal lath.
Okay, I remembered I have some pictures, there does appear to be a mesh fixed over the EPS before the render.
EPS fixed:
Initial layer of render/base:
Completed finish:
If you tap the wall from outside, it feels hollow.
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