Filling a Wall - With What?

anotheruser

Shelf fell down from the wall.
Left a little bit of a hole, which turned into quite a bit (about the size of an egg if squashed flat) of brick exposed.
I filled it in with some general purpose filler and set a rawl plug in it, which I know is perhaps not the best idea but I didn't want to bother filling, then drilling another hole.
Put the shelf back up but after a small test of weight, it came out from the wall very slightly.  Took it down again and investigated, it seems the filler didn't really bond to the brick that has now been exposed.
Should I look at something like no more like No More Nails?  I have a cheaper version of but not sure if this will work.  Tried mixing the filler with a bit of PVA glue to strengthen it, which seemed to work but again, didn't really bond to the brick very well (although it was still a little damp).
The shelf needs to be in the same place.

Astrozombies

You need to drill into the brick, drilling into the plaster won't do anything.

Davesnave

Longer screws and a fix into the brick, as above.

anotheruser

Who said I drilled into plaster?
I drilled into the brick but it's crumbled.

There may be thin plaster on the brick but it's more like skimming plaster rather than plasterboard - only a few mm thick.

stuart45

I've used Ciment Fondu for similar repairs in the past. Goes off really quick and is rock hard in no time, but is quite expensive to buy a bag for just a small repair. Sand/cement mortar with a touch of plaster goes off quite quickly, but is known in the trade as a bit of a bodge. 

Davesnave

anotheruser said:

Who said I drilled into plaster?
I drilled into the brick but it's crumbled.

There may be thin plaster on the brick but it's more like skimming plaster rather than plasterboard - only a few mm thick.

If it's crumbling, its a very poor brick, but it may be something else like aerated block or those horrible dark grey blocks made from something like ash that were popular in the mid C20th.

You may need a specialist fixing or an oversized hole and some of that chemical resin stuff.

stuart45

Davesnave said:

 those horrible dark grey blocks made from something like ash that were popular in the mid C20th.

They were the true breeze blocks made from coke breeze.

FreeBear

anotheruser said: Should I look at something like no more like No More Nails?  I have a cheaper version of but not sure if this will work.

If you go that route, use a solvent free version. Spray some water in to the hole, then pump your grab adhesive in before inserting the wall plug. It would be worthwhile drilling a deeper hole, and press two wall plugs in. A longer screw will be required, but it will grip over a longer length and be less likely to pull out.

Jeepers_Creepers

A photo of the existing hole, Anotheruser? Just how crumbly is the material? It might need enlarging and resin.