Houston Realtor Offers Important Advice on Buying an Older Home in Houston

When buying an older home, there are many precautions a Houston Realtor should suggest their buyer take when effectively evaluating the condition of the home based on the age. While there are many factors to consider, one of the most important is the condition of the drain pipes in the foundation. Before the 1970’s era, most homes were built with cast iron drain pipes.  Although they were the best material at the time, it has now been shown that the average life of these pipes are roughly 40-60 years. While some cast iron pipes might look intact from the outside, they rust and deteriorate from the inside. When you take the average older home built in the Meyerland area which was built in 1960, we can quickly see that these homes need a closer examination before a buyer decides to purchase a older home in Houston.

Before we look at the testing procedures, let’s first look at the damage these broken pipes can cause. The first source of damage is foundation failure. Think of your foundation as a sponge. If one side or part gets wet, it swells up while the other dry side or part stays in place. This can cause differential settlement – a fancy word for your slab being stressed by it moving in different directions due to soil conditions.  In addition to this movement,  when broken pipes are releasing water beneath the foundation, both the leaking water and the water that flows back into the pipe carries away and/or erodes the surrounding soil which creates voids leading to another source of foundation failure. Finally, it goes without saying that having sewage potentially percolating in your yard or up through the foundation itself is pretty disgusting.

Now that we have identified that cast iron pipes can be a huge potential for foundation failure, let’s look at the different ways to diagnose these defects. The three types of test we will examine are the camera test, hydrostatic test and finally, the isolation test.

The camera test is what a majority of buyers chose to diagnose these potential defects. With this type of test, a camera is fed through the pipes to look for cracks and the general condition. This test is the most affordable(usually $200-$300). The only problem with this type of test is that pipes can be so corroded or broken that the surrounding dirt fills in the voids which makes them look intact. In addition, they can also miss loose fittings and other defects that are not visible to the camera.

The next type of test, the hydrostatic inspection  approaches the diagnosis from a different perspective. With a hydrostatic test, the main sewer line is blocked and water is filled in to the parts of the drain system. If the water level falls, that is a clear sign that there is a break in the line. Once a leak is discovered, they can move into what is called an isolation test. In this test, the sewers are blocked at various points to pinpoint exactly where the break is. The cost for a hydrostatic test usually starts at $275 and will increase if the plumbing system is divided into separate systems. The isolation test usually costs the same as the hydrostatic. Opponents of the hydrostatic test usually mask their concern with the opinion that is causes pipes to leak that normally wouldn’t. The intelligent was of explaining it is that if there are breaks on the tops of the pipes and the system is filled with water, then the test will show a leak. Under normal conditions, the system might not be completely full with water to make it leak from the top of the pipes.

The truth is, a lot Houston Realtors have the opinion that “hydrostatic tests usually just cause more problems”. Other than the question of the plumbing system being completely full under normal operation, I can’t see nor has any inspector seen a hydrostatic test “cause problems”. In addition, I am not aware that any organization that formulates plumbing codes has an acceptable number or breaks or leaks that is considered within tolerance, therefore buyers should insist on a plumbing system that is intact and holds water.

It is very concerning that having either type of tests are not automatically suggested by a buyer’s agent, and why agents only schedule them at a buyers request. At a recent hydrostatic test I had a listing agent do/say all of the following:

1. Upon being informed we were doing the test I was told, “I only do camera tests because hydrostatic test cause problems.” – Yes, the discovery of an under slab leak should be considered a problem.

2. After being called to the inspection and shown the leak, her response was, “of course it will have leaks, the home is over 50 years old”. – I must have missed that in the sellers disclosure.

3. I was then told that the sellers had not reported any problems with the plumbing system. Well, they didn’t need to. The fact that the home had foundation repairs on two separate occasions was enough for me to assume the cause was the leaking pipes. In addition, neither foundation company had performed either test after the foundation repair. Along with the age of the pipes, raising of a foundation can also cause these breaks in cast iron pipes.

If you are buying a home that might have cast iron plumbing pipes, the first question to your Houston Realtor  should be to find out of they have already been replaced with PVC pipes. Many sellers through the discovery of foundation problems have elected to improve their homes by replacing the cast iron pipes with PVC pipes. While this is a costly repair item (roughly $10,000-$15,000) is is necessary to ensure an intact plumbing system that will not cause foundation failure. If this pipe replacement has already been completed, find out the extent of the repair as sometimes sellers will only repair a certain part of the plumbing system that is broken. If the seller does not have complete documentation that the entire system has been replaced, do yourself a favor and schedule the test of your choice to evaluate the plumbing system.

In closing, don’t let an agents lack of knowledge or attempts to minimize potential problems sway you from protecting your interests by getting a professional to test cast iron pipes. In addition, know the value of of under slab pipe replacement to either factor into a future repair or to add value for a home that has already had this done.


Broken Cast Iron Pipe - Houston

Broken Pipe Under Slab

Broken Plumbing Pipe - Houston

Close Up View Of Pipe Decay


If you liked reading this article, please read Caution on Homes withFoundation Repair