Im putting up this screen this weekend. It weighs 9kg. I was just going to use 4 2 inch screws. But now Im worried that itmay not be enough. Is there a rule of thumb for screws and weight, especially as someone is going to be tugging at it. Was going to use 2 inch scres, into 1.5 inch raw plugs in 3/4 inch plaster/solid brick. (no studed partition) Should I go 3 inch, 4 inch even?