We call the pipes that deliver water under pressure to the plumbing fixtures in a home “water supply piping.” In the Gainesville area, homes built after approximately 1950 have both the water supply pipes and the drain pipes installed in the ground under the level of the floor slab before the concrete is poured in place. Pre-1950 homes typically have an elevated wood floor and the water supply piping is installed in the crawl space between the bottom of the floor and the ground.

   When a home that is slab-on-grade needs to have older, failing water supply piping replaced, the new pipes are usually run through the attic and the older pipes simply abandoned. So if you have water supply pipes in your attic, it is probably because the original pipes have been replaced. The attic supply pipes should be wrapped in insulation to protect against the possibility of freeze-fractures during a hard winter freeze.

   You may see pipes in your attic even if all the water supply piping is under the floor slab. There are two types of pipes, other that water supply, that are typically found in an attic: 1) vent pipes for the plumbing drain system, like in the photo above, that extend through the roof and are usually larger diameter and, 2) piping for natural or propane gas that runs through the attic and then down to a furnace, water heater, or fireplace.

    There is also one other location where the water supply pipes might be located if the house has been repiped. If the house does not have an attic or it is too shallow to move around in, then the new pipes may have been run in the ground around the perimeter of the exterior walls. If the pipe has been installed this way, you would see pairs of pipes with insulation around them coming up out of the ground approximately one foot high and then turning into the wall outside the kitchen and bathrooms.

    Also, see our blog post Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water?

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Here’s links to a collection of our other blog posts about PLUMBING PIPES:

• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?

• Can galvanized steel pipe still be used for new water lines in a house? 

• How can I tell if I have cast iron pipes in my house? 

• Why can't a sanitary tee be used for a horizontal-to-horizontal drain pipe connection? 

• What is the difference between green and white sewer drain pipes?

• Is a washing machine drain hose required to be secured at the standpipe?

• What are the abandoned pipes sticking out of the wall in my house?  

• What are the code requirements for plumbing vent terminations?

• What are the code requirements for layout of drain piping under sinks?

• What causes a gurgling sound when a bathtub or sink drains? 

• What is a "combination waste and vent" in a plumbing system? 

• What is a building trap?  

• What is a galvanized nipple?

• What are the pipes sticking out near my water valves?

• How do you accurately find a broken water pipe leak under the floor slab?

• What is the difference between water pipe and sewage (waste) pipe? 

• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water? 

• Is a hot water faucet handle required to be on the left? 

• What is a dielectric union? 

• What's that powdery crust on the pipe connections at the water heater? 

• If all the plumbing drains have water in them and you can still smell sewer gas, what's causing the problem?  

• How can I tell what type of plumbing pipe I have?

• What is a P-trap?

• Why is old galvanized steel water pipe a problem for homebuyers?

• What does polybutylene pipe look like? Why is it a problem? 

• Which water pipes are an insurance problem and possibly uninsurable?

• Can you connect CPVC pipe directly to a gas water heater?  

     Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.