How to anchor MDF on to a brick wall which has plasterboard in front?

[Burnings]

Brick wall house constructed in the 90s. It now has plasterboard in front of the bricks - which I am guessing is a dot and dab wall so about 5 - 10mm void between the plasterboard and the bricks. 

On to this plasterboard (then anchored in the bricks), I need to screw in an MDF (which will then have a pinboard on it - with the intention of hanging a professional ( > ~5 kilos) dart board) board. Question is what can I use to anchor the yellow tongue 1000mm x 500mm on to this plasterboard? 

Google suggests using Corefix Dot & Dab Wall Fixings. YT videos make this option look promising. Essentially has a plug that can be hammered into a drilled hole. Then a metal sleeve is slid in - then a bolt. I find no equivalent in Australia, at least on google. I can't just use Anchor RamPlug kind a thing because as I screw in - the plaster board will bow/bend in. Feels like I am surely searching incorrectly - I have read https://www.workshop.bunnings.com.au/t5/How-To/How-to-hang-just-about-anything/ba-p/87672 - but it doesn't contain anything for my situation. 

[EricL]

Hello @Burnings 

The only other fixing that comes to mind that will provide a firm hold is Ramset 300ml Chemset UltraFix Plus in combination with Ramset M12 x 160mm ChemSet Anchor Stud along with Ramset Multifit Sieve - 4 Pack. These fixings are sometimes used for post fixings and as heavy duty anchors. 

Here is a handy guide: Ramset™ UltraFix PLUS Polyester Anchoring Kit

Let me call on our experienced members @Dave-1, @AlanM52 and @Noyade for their recommendations.

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Evening @Burnings 

I like masonary bolts I know you are concerned about the plaster compressing but over a large area that the MDF sheet will cover it really shouldnt be a problem.

So a test hole  or two (somewhere behind where you are going to mount the MDF) to make sure that there is brick or cavity there. Yeah I was caught out when I went to hang a 50kg plus old school screen on the wall. Half was like you describe, the othe rhalf was a cavity! Yeah can you hear my words lol 

I would just use your philips head screwdrive and a few twists with the blade against the wall to go through the plaster and hear what will be brick or air

Then if its brick I was thinking of Ramset 8 x 60mm Galvanised AnkaScrew Masonry Anchor or maybe 80mm long.

Hold your MDF sheet up (support with a piece of timber underneath and predrill your 6 holes through the timber) mark the holes. and then drill them to a bit deeper then the bolts (in case there is dust left in the holes) Then I would screw in the first two bolts diagonally opposite each other and then the last 4. 

You could sand teh edges of the MDF first and paint it before to make install look nicer

Dave