Note the fire sealent hasn't been installed yet in this image.



The camera on my phone has done something interesting on this photo. While newbuild quality isn't up to much, the vent should be straighter than that.


I had considered that, but the garage is on a piled beam foundation like the house foundation shown below. The slab upstand that you see is more for levelling the ground as the drawings for the house has a 1:8 slope on the garden which would have been grim.spread-tee wrote: ↑Wed Apr 20, 2022 11:00 pm You might be hitting the house foundation that close to the wall, they would normally project 15-20cm out from the face of the wall, but could be more.
Desp
My thoughts exactly, drill into it to get an idea of thickness and if seems ok drill and use chemical anchors and attach the Unistrut to that.Countrypaul wrote: ↑Thu Apr 21, 2022 9:57 am Why break out any concrete if it is that large a lump, just fasten to it instead?
but how well earthed is the concrete? I could imagine a beam sitting on piles like the horizontals at Stonehenge... not a lot of electrical continuity there! And the beams not being in much contact with any made ground.Fintray wrote: ↑Thu Apr 21, 2022 11:17 amMy thoughts exactly, drill into it to get an idea of thickness and if seems ok drill and use chemical anchors and attach the Unistrut to that.Countrypaul wrote: ↑Thu Apr 21, 2022 9:57 am Why break out any concrete if it is that large a lump, just fasten to it instead?