Home / Stair treads off-level - subsidence in close or rot in timber supports to landing - serious Stair treads off-level - subsidence in close or rot in timber supports to landing - serious Gaps between internal steps - treads should lock together - serious and urgent Stair tread cracks - may be sign of serious problem See also Stairs Get updates by email We send occasional legal and technical updates My interest is as an: Owner Technical / Professional Property Manager