im thinking about putting a shelf up to put my fishtank on in one of my alcoves. the gap is about 1.2m how much weight could three 47mm x 75mm battons across this width take? (worked out the weight to around 450kg) any help would be much appreciated
each batten will carry one third the weight, or 35kg give or take. shouldn't be a problem though they may bow over time, i'd be inclined to use 4x2 or 50x100 instead. but the shelf will still only be as strong as the fixings in the wall.
I would be wanting to support the shelf with a simple frame at either end that takes the load down to the floor and not directly into the wall as you will need substantial fixings to get it to stay in the wall otherwise.