internal plaster walls with shelf fixings

[mreco]

hi
weve moved into a house 11 years old, and i need to fit a shelf racking system to the wall.
im trying to work out if the rawlplugs for plaster board walls should go all the way through the plaster board.
I think (ive drilled) there are two layers of board each side of the wall, with a gap in the centre of the wall (approx total wall thickness 100mm)
i think the first layer is 15mm then a small gap then another board layer make up each side of the internal wall
i dont know if the rawlplugs should go through all the plaster layers and the prong bits end up in the main center gap or the prong bits only need to go behind the first layer of plaster board.
it will be shelfing for the whole wall floor to celing on those twin gap batterns and clip in arms (approx size of wall 2.3m high x 2.6m long)

Do they even make rawlplugs with about 30-35mm of shaft before the prongs that point outwards?

any advise appreciated

thanks
simon

 

[Joe-9T]

hi

i think the first layer is 15mm then a small gap then another board layer

any advise appreciated

thanks
simon

you sure you havnt drilled through a pipe or something?

 

[joe-90]

It sounds like that compressed straw board to me. that had holes running through it. If the shelf is for light duty you can get lengths of rawlplg that you cut off to whatever length you want. The work by expanding the plug causing friction in the hole (ooer missus). The 'prongs' don't matter.

 

[mreco]

no pipes drilled through.
its plaster board, ive seen the stuff that i drilled out.
i did two holes to make sure the guess at the construction consistant

the shelf is more like for medium use

 

[mreco]

ive drilled a bigger hole to see whot the wall is made of, this is it.

3 sheets of 12mm plaster board...cavity.... 3 more sheets for the other side

6x75mm spring toggles arnt long enough!! just wont go in enough for the toggle to spring open

what is best to use?

UPDATE
bought some longer bolts 80mm.....JUST long enough.. JOB DONE