ᐅ Anchors and screws for aerated concrete hollow blocks with external insulation

Hello everyone,

I am working on installing electrical wiring inside a garage wall.

The problem is:

the wall is made of hollow sand-lime bricks, covered with 4 to 5 cm (1.5 to 2 inches) of extruded polystyrene insulation boards, all plastered over.

I’m having trouble finding the right anchors and screws to mount cable ducts and outlets. I keep ending up hitting the cavity inside the sand-lime bricks.

Do you have any suggestions?

Best regards,
Zippler

In an emergency, I would use toggle bolts.

Hollow wall anchors?

I might consider gluing the cable ducts. Of course, sockets should be screwed in if they are surface-mounted.

Otherwise, for these kinds of cases, you can also inject expanding foam into the drill hole and then glue in a wooden dowel rod.