Notches and holes

Notches

• Should only be made in the top edge of the joist
• Should be no deeper than 0.125 times the depth of the joists.
• Should be no closer to the support than 0.07 times the span and no further away than 0.25 times the span.

Maximum notch depth

Holes

• Should only be drilled on the centre line of the joist.
• Should have a diameter no greater than 0.25 times the depth of the joist.
• Should be no closer together than 3 times the larger diameter.
• Should be no closer to the support than 0.25 times the span and no further away than 0.4 times the span.
• If the above requirements cannot be met within the limitation shown, then increase the joist depth by the depth of notches or diameter of holes.