Wall between house and linked garage - part - brick, part - ???

[tmasa]

Trying to put a TV bracket on the wall between house and linked converted garage (on garage side).

Assume it would be structural, all brick with plasterboard on top.

Drilled 2 holes - one brick after plasterboard, the other one went too easily, but it is not hollow behind plasterboard, some material I can't identify, most debris fall into plasterboard gap. About 6 cm deep.

The wall is double normal width, and stud finder picked one stud only near the edge where garage door is.

I don't understand why the same wall has different structure 15cm apart and what plug should I use in the second hole?

Thanks

 

[23vc]

Spring toggle type fixing

 

[tmasa]

Spring toggle type fixing

I have heavy duty anchors which should work the same, but a bit hesitant mounting 55" 15kg TV partly on plasterboard, there are only 2 fixing points for this bracket.

 

[23vc]

If you’ve got a solid fixing into the masonry it’ll be fine. Or, cut out and put a noggin in if you’d rather. But I’d just crack on

 

[endecotp]

not hollow behind plasterboard, some material I can't identify

Dot-and-dab adhesive?

Mortar?

 

[foxhole]

One concrete screw securely fixed will hold a tv.