When a joist is notched at the bottom to bear on a ledger, the notch should be a maximum of?

The appropriate maximum depth for notching a joist at the bottom to bear on a ledger is indeed a quarter of the depth of the joist. This guideline is established to maintain the structural integrity and load-bearing capacity of the joist. Notching beyond this limit can significantly weaken the joist, making it more susceptible to failure under load conditions.

By limiting the notch to one-quarter of the depth, it provides enough support while allowing for the necessary adjustments to connect with the ledger properly. This advice aligns with safety practices in construction, ensuring that the wood remains strong enough to bear intended loads without compromising structural stability.

The other options suggest greater limits on the notch, which would not adhere to best practices in structural engineering and could lead to an unsafe installation. Thus, limiting the notch to a maximum of a quarter helps maintain a balance between connectivity and structural strength.