Inch think crumbling wall

[Shjglasgow]

Hi

Trying to screw in a book wall unit to wall however wall crumbles over an inch before actually hitting brick. I remember having to pay a professional to hang TV on the same wall and he had to call another person to help him a few years back.

I know have a massive whole, which I'm happy to fit in but would like to know how to stop this happening again.

The screws/plugs that it comes with wouldn't even touch it due to the plaster depth. (Yellow raw plugs) I've tried to use the plaster plugs instead but the wall still crumbles.

I've put wall units up / TVs up on other walls in the flat without any issues but this one wall is an absolute nightmare.
I'm using a Bosch cordless drill on normal drill setting through plaster then hammer setting when going into brick. I'm in an old tenantment flat in glasgow.

Any ideas? I'm in the verge of trying to use no nails on the entire thing which I know more than likely end in disaster!

Thanks sam
[GALLERY=media, 103221]20190901_130711 by Shjglasgow posted 1 Sep 2019 at 1:09 PM[/GALLERY]
[GALLERY=media, 103220]20190901_130717 by Shjglasgow posted 1 Sep 2019 at 1:09 PM[/GALLERY]
[GALLERY=media, 103219]20190901_125036 by Shjglasgow posted 1 Sep 2019 at 1:09 PM[/GALLERY]

 

[Mottie]

With an inch of plaster, I’d suggest drilling deeper and using 2 1/2” screws.

 

[CJRatch]

We've the same plaster in my house I think it's sand, lime and horse hair or similar. You need to get a good fixing in the brick. You've barely touched the brick in that picture.

Start your hole nice and small otherwise it'll blow the plaster as it has done.

How thicks the material your fitting to the wall? Presuming it's a thin bracket and the shelf hooks on to this as above 70mm screws and plugs will give you a good 50mm fixing in the brick. If thicker than a thin bracket you'll need longer screws to accommodate this.

 

[foxhole]

4mm masonry bit then open up to 6mm. 6mm wall plug and 60-70 mm screw should do it.
Don’t waste your time with supplied screw etc , usually cheap rubbish.

 

[Shjglasgow]

Thanks everyone. I'll give it another try with the above suggestions this evening