OK i know in short just screw the bracket in.I already have a piece of wood installed on top of the metal brackets and there's about 20mm gap from the bottom of the wood to the bottom of the ceiling.I can figure out which orientation the wood is installed because the wires are slipping out from the side so i can see the wood edge on 1 side. i forgot how long (should be sufficient) or how thick (should be thicker than those puny wood).All the brackets have 5mm hole for screws.So now i have few questions before installing.1.What type of screw, material & size & length should i use? Do i use Woodscrews that have no thread near the screw head (this means i cannot get screws too long as the threads might miss the wood by going over it (20mm gap between wood bottom and ceiling surface)? the screw holes around 5mm so i can only use #6-#8 screw to fit? will #10 screw fit? I heard bigger screw holds the weight better? and is the material of the screw important? because i heard about galvanic corrosion when 2 different metal are in constant contact causing rust (is stainless steel screw a save bet?) Since mushroom head philip wood screws (that can sit flat on the bracket) are hard to find i plan to put a washer before the non-mushroom screws to distribute the force evenly but worry about the corrosion issue. Also what screw length is recommended?1.Since i can only see 1 edge of the wood and not sure the width of the wood, how far should i screw the screws in from the side to get better grip? Is there a rule of thumb the minimum distance between 2 screws to avoid the wood breaking causing both screws to lose grip?3.if i'm using woodscrew, do i still need to drill a pilot hole before installing the screws? i saw some cabinet guys working on wood they just put the screws on their powered screw and screwed them in. they don't seem to be using wood screw as the threads go all the way from bottom to top.I know it's super easy to install the bracket, just screw 2 screws in. but what are the chances of over tightening the screws and warp or damage the plaster ceiling? via /r/DIY https://ift.tt/2yFsaLe
