I am trying to help out a "fellow ST fan", who has just completed EWI and wants to upgrade & reinstall solar thermal to wall.

(new set-up = 3 x Tinox GM, tempered Low-E glazing, 2.5 m2 each. ( Weight not stated...)
Including tubular-steel support structure (3mm thick walls...)

Problem now arises re how to fix through 100mm EWI & into block wall...

The sketch suggests using threaded 20mm SS bar & is the only suggestion received so far...

Despite my reservations for the suspension principle, period, I feel inclined to suggest thinner mild steel bar, inclined *upwards* into the blockwork; with steel-tube sleeves inside foam-filled PVC liners through the EWI, & big washers, for anti-compression etc.

Photo shows old installation, pre-EWI...

all / any opinions welcome.

gg

Either run steel bars, one each end, (e.g.50mm x 6mm) from the roof and hang the panels from these with fixings at the panels through to the wall or steel box section from the panels down to the ground again with fixings at the panels through to the wall. The idea is to remove any sheer loading on the fixings going through the EWI

Mild steel conductivity is three times worse than stainless steel, quite apart from any corrosion concerns. So I would definitely use SS for any penetrations and I'd probably use SS (ideally A4) for exposed parts for the sake of long-term appearance.

I think it will be worth double-checking the calculation of section sizes. Things like '20 mm' or '50 mm x 6 mm' sound like much bigger than needed.

I'd have thought that multi-strand stainless rigging wire would be fine for suspension cables from the roof. Something like 4 mm 1x19 balustrade wire would be suitable I'd think and all the end fittings are easily available. Talk to a local rigging specialist to check sizes etc.