The Operating Systems, Lower Level, Interior and Exterior Inspection sections are EXTREMELY condensed versions of those found in our home inspection book: Home Inspection Business From A to Z
Real Estate Appraisers are not required to be home inspectors. However, I will include these sections anyway to give you some basic details about home inspections.
Look at all visible plumbing lines. There will be very little to view in a finished basement or behind walls and ceilings. Check for any corrosion, leaks or any buildup of mineral deposits. There are several types of plumbing line materials including Copper, Brass, Galvanized Iron, Lead, PVC, and Cast Iron.
Often you'll see water stains on some of the floor joists, which are the beams that support the floor above. You'll also see water stains on the sub flooring, which is the base for the floor above. Minor water stains are normal, especially underneath kitchens and baths. You need to be concerned about extensive water damage. If any doubts exist, check the floor above the damaged or stained areas. Try bouncing on the floor above during your interior inspection to see if there are any problems.
Check the water main line where it enters the house. The water main for a house connected to a city water system is usually located in the lower level at the base of the foundation wall facing the street. The water main for a house connected to an on-site well water system is usually located in the lower level at the base of any of the foundation walls. Ask the owner or Realtor if you can't find the main water line. Sometimes they're behind personal items or finished walls in the lower level.
Find out what type of pipe material the main water line is made of. Usually it'll be copper for a house with city water and it may be plastic for a house with well water. Lead piping is very rarely found in my area. It's not used any longer because the lead content can seep into the water supply which is very hazardous. These pipes will always leak some amount of lead content into the house water supply. A lead main entry line will be silver in color and may have a small bubble-type bulge in the beginning of the line. This bulge is known as a "wiped" joint. If you see a lead main water line or any lead piping in the house, highly recommend that the client have a laboratory water analysis done for safety. Also, recommend that all lead piping be replaced with a new pipe for safety. The reason for this is that lead poisoning is the NUMBER ONE childhood disease in the USA. Lead is an element that doesn't break down when it gets in your system. The effects of lead poisoning in children are irreversible!! Lead poisoning can damage the kidneys, nervous system and blood, and can cause permanent brain damage. So don't take any chances with this stuff.
In older houses there will be lead in some of the soldered pipe joints. Gradually, over time the amount of lead in the solder will be reduced from leaching into the drinking water. Ice makers are prone to very high lead levels. The water in a freezer ice maker can sit in the pipe for days. This allows enough time for the lead to leach into the water at high levels. A lead abatement contractor told me that he's tested houses where the children had extremely high levels of lead in their bodies. He said that after the test results came back, almost all the lead in their bodies was coming from the ice cubes!
I'm telling you ahead of time, that if you come across any lead piping in a house, some Realtors and other third parties will try to sugarcoat the problem. They're going to tell your client that "they only need to install a water filter and it'll be fine." Don't let your client be snowed with that line! Tell them to remove all lead piping and eliminate the problem for good.
Check for an electrical grounding wire. This is a very important safety item!!! It should be located by the water meter or the entry of the water main line. The purpose of this is to ground the house electrical system for safety. Electrical systems can also be grounded to an exterior metal rod driven 8-10 feet into the ground. The grounding wire doesn't have to be insulated like most electrical wiring because there's normally no current passing through this wire. It may be enclosed in BX cable or a conduit, which is a metal covering for protection from damage.
The grounding clamps should not be rusty or loose, but often they are. The grounding wire should be clamped on both sides of the water meter, if there is a water meter installed. If there is no water meter, then the grounding wire should be clamped on both sides of the water main shutoff valve. Often it will only be clamped to one side of the water meter or main shutoff valve. Tell the client that they need to have a jumper cable installed with clamps to span the water meter. This is an inexpensive item to install and it's a safety requirement of the National Electric Code. A jumper cable is merely an additional heavy gauge wire about three feet long that's attached on both sides of the water meter. A jumper cable normally doesn't need to be an insulated wire because no electrical current should be passing through this wire unless there is a problem condition.
During the interior inspection check the water pressure and drainage by briefly running the faucets and tubs. In the bathrooms run the sink faucet, the tub or shower faucet and flush the toilet simultaneously. Watch the faucets to see if the pressure drops significantly. A minor pressure drop is normal but a large pressure drop can indicate either poor water pressure or clogged supply lines. Poor water pressure in some supply lines may be due to the street water pressure being too low. However, it's most likely caused by some supply pipes inside the house that have clogged over the years. Tell the client to have a licensed plumber check it out to determine if there are many clogged lines or just a small section that needs replacing.
Don't forget to turn off any faucets that you're testing during the inspection. You don't want to flood the house. Water damage can be very messy and expensive to repair.