Final answer:
When joists and beams are in contact with bare concrete walls, a sealant should be applied to protect the wood from moisture. Checking local building codes for sealing recommendations is advisable, and consulting with an engineer may be necessary for broader structural concerns.
Step-by-step explanation:
When joists and beams have contact with bare concrete walls, the best course of action is usually to apply sealant. This is because concrete can potentially transfer moisture to the wood, which could cause the wood to rot or lead to mold growth. Using a sealant acts as a barrier to protect the wood from such moisture. It's also a good practice to check local building codes or recommendations for specific sealing products or methods. If the interface between the wood and concrete is part of a broader structural concern, or if there's uncertainty about the best sealing method, it may be necessary to consult with an engineer.