What can cause crumbling in cast iron pipes over time?

Crumbling in cast iron pipes over time is primarily caused by corrosion and aging. Cast iron is generally durable but susceptible to rust when exposed to moisture and certain environmental conditions. Over many years, the internal and external surfaces of cast iron pipes can corrode due to the presence of water, soil acidity, and other corrosive elements. This corrosion leads to the gradual deterioration of the material, resulting in crumbling or flaking as the structural integrity of the pipe weakens.

Additionally, aging is a significant factor because cast iron pipes can be quite old, especially in older homes and infrastructure, and have been subjected to decades of potential corrosive influences. The combination of these effects can lead to a deterioration that manifests as crumbling.

While other choices like excessive heat, poor installation, and improper sizing can certainly impact plumbing systems, they do not specifically lead to crumbling in the same way that corrosion and aging do. Excessive heat might cause other issues, such as expansion or warping, but it is not a primary factor for crumbling. Poor installation could lead to leaks and other plumbing failures, and improper sizing could cause pressure issues, but neither would directly result in the crumbling of the pipe material itself as corrosion and aging would.