First grab your level and lay it across the back edge, take note of which end the bubble floats to. If it is in the middle, between the two lines then the back edge is level, if it has floated to one side, then that is the high point.
From the high point, set your level from that corner to the front corner, take note of which end the bubble floats to again. If the bubble is at the same end as your last high point, then this is where you need to start levelling the cupboard from. If the bubble floats to the opposite end to the previous high point, then you need to repeat the process from this new one.
Once you have determined exactly which corner is the highest point, you then need to work backwards. Place your level along the edge of the highest point. Grab some packers and place a couple under the opposite end until the bubble is in the centre. Once you have worked out how many packers this requires, take those packers and place them under that bottom corner of the cupboard.
Tip: If the cupboard is too heavy to lift or too awkward to lift the corner on, take your chisel and block of wood, place the block about 40mm away from the bottom edge of the cupboard. Next grab your chisel and place it on top of the block of wood with the front edge of the chisel wedged under the edge of the cupboard. Then push down using the chisel as a lever action, once the cupboard lifts, pop the packers under the edge.
Once you have that edge of the cupboard levelled, do the same to the next side, repeat the process until all 4 sides are level.
If the cupboard is rather tall, you can use level the cupboard by placing the level on its edge running vertically. This is called levelling for plum. The principles are the same as when levelling the way mentioned above.
Tip: How to determine if your level is still actually level. Start by placing your level on the edge of a cupboard. Pack the level up until the bubble is in the centre. Once you have done this, pick the level up and turn it around 180 degrees. If the bubble is still in the centre, then your level is fine, if it is no longer in the centre, it’s time to get a new one or change the bubbles if your level has this option.
To ensure your level is still plum, rest it against a wall and position so that the plum bubble is in the centre, draw a line down the side of the level. Next flip the level over and line it up with the line. Once again, if the bubble is in the centre, your level is fine, otherwise it’s time to replace the level.
That’s it for this one.