You depend on your water supply lines to safely bring drinking water to every tap in your home. Eventually, though, those lines may begin to fail. Know the signs so you can schedule a repair before the damage becomes too severe.

1. Moldy Walls

Mold needs moisture to grow, so if you start finding mold in areas that should be dry then it's time to consider the cause. Mold can be due to a supply line leak if it occurs under a sink, on the ceiling below a bathroom, or if there are supply lines running behind the moldy wall. Always find out the cause of the mold, don't just clean it up and hope the problem goes away.

2. Corrosion Symptoms

Although plastic pipes are used in many new homes, some homes still have metal supply lines. These lines can eventually rust or corrode. If the outside of the pipes appear to be discolored, dimpling, or flaking, then corrosion has begun and the pipes need to be replaced before they spring a major leak.

3. Rusty Water 

Rust in the water can come from a variety of causes. For homes on well water, it is always a good idea to have the well tested if the water is discolored to first rule out water quality issues.  If your neighbors are also having rusty water, then the issue is likely in the municipal supply line. On the other hand, if only your home is having issues, then the old water supply lines could be rusting from the inside out. This is especially likely if there is other residue in the water, such as grit or metal flakes.

4. Fixture Stains

Stains on the inside of your sink or tub, particularly orange, green, or brown stains, can be a result of iron and metals in the water due to rust and corrosion. Although these stains can also occur with hard water, if your home has a water softener and the fixtures are still developing stains, then it is a good idea to have a plumber in to inspect the pipes for possible damage.

5. Slab Cracks

For homes on a slab foundation, the water lines often run beneath and then penetrate through the slab in order to enter the home. If the supply lines fail under or inside the slab, then your foundation may develop cracks or begin to settle unevenly. You will need a plumber to fix the lines and a foundation contractor to repair the foundation.

Contact a plumbing service if you want to have your water supply lines inspected.