This is an interior camera shot of a heat exchanger from a furnace. The issue here is the corrosion and perforation evident in the metal, therefore carbon monoxide is being released into the air ducts. This furnace would be condemned immediately by the gas company and a new furnace would need to be installed. It is highly recommended to have your furnace inspected on a yearly basis for safety and operating in its highest efficiency.
It is recommended that using steel roofing when shingles have met their life expectancy, is better for the environment since steel has a longer life span than shingles. Yes, steel roofing is more expensive, but you won’t have to replace it again in your lifetime.
Soffits, facias, and roof vents should be monitored for damages by animals. Here is an example of squirrels in the attic that have damaged the insulation, Vapour barrier, and the excrement is visible in all areas. It is recommended to remove all material in this attic, clean the excrement of animals and apply new blown in insulation.
Every house that has a forced air heating system should have ducts cleaned . Ducts should be cleaned particularly after renovations , or after a owner has taken possession of new residence . Here is an example of house that has not had a cleaning , perhaps ever . There was also evidence of mouse droppings and other material within air ducts.