You know you’ve got something wrong with your under-slab plumbing. But is it a leak or is it a clog or something else? You know very little about plumbing but want to know how to distinguish an under-slab leak from other kinds of issues. Help!
At Anchor Foundation Repair, we work with plumbers all the time because we do under-slab tunneling and foundation repairs. Both of these repair services are intertwined with your under-home plumbing. We see firsthand the signs, damage, and repair options available to you in these situations.
*Honesty Alert* We’re not claiming to be plumbing experts here. But after tunneling thousands of feet under Brazos Valley homes and working with countless plumbing professionals, we are quite familiar with under-slab plumbing leaks in particular.
This article describes and explains the typical signs of under-slab plumbing leaks. Then, we discuss short-term and long-term ways to solve these leaking problems. By the end of this info, you will know where and when you might have some options in handling your under-slab plumbing repairs.
Typical Signs of Under-Slab Plumbing Leaks
Under-slab plumbing leaks most often occur with your drain lines rather than your water supply lines. Drain lines are the ones that take the used wastewater away from your home. The drain lines can either join up with a municipal sewer system in the city or your septic tank if you’re in the country.
No matter where you live, there are some typical signs that you’ve got a leak in your under-slab drain lines:
- Slow-draining fixtures after blockages or build-ups have been ruled out,
- Gurgling drains,
- Recurring back-ups, and
- Smells.
Don’t worry, we’ll elaborate on these a little to explain why these are indicators of under-slab plumbing leaks.
1. Slow-Draining Fixtures After Ruling Out Blockage and Build-Up
Any drain line can drain slowly if there’s something partially stuck in it, from toys to waste material, to (sorry) food gunk, cooking fat, or hair. Once those situations are cleared away by a plumber, your drain lines should flow freely.
If the drain lines still don’t flow quickly after clearing blockages, then the lines could be cracked, broken, or separated. With compromised drain lines, the wastewater doesn’t know quite where to go. Some might flow down the pipe, but more might flow into the dirt under your home through the cracked or separated line.
The water has difficulty flowing through this *dead end made of dirt* and it takes longer for the fluid to drain from your lines.
When the wastewater is not flowing unimpeded, a slow drain results in several issues. For example,
- Your shower fills up a couple of inches while you are in there getting clean and then eventually drains away after you’ve gotten out.
- You wash your dishes by hand, and then when it’s time to empty the sink of water, it takes forever to flow away.
- Your child has a bath, and there’s still water slowly draining in the tub after the 5th bedtime story.
Your plumber might encounter mud when attempting to clear the lines. Finding mud in your lines is a huge indicator that your drain lines are not intact and are compromised in some way.
Slow-draining lines are not the most terrible thing in the world and can be tolerated for a while. Just keep in mind that at some point it’s likely to go from slow draining to *no draining* when you don’t have time to deal with it or you’d rather not, i.e. the weekend when plumbers like to charge double. Plus, this can eventually cause foundation issues and more costly repairs the longer you put things off.
2. Gurgling Drains
When your drain lines are cracked or broken, or sections are separated from one another, air gets into the lines that is not supposed to be there. Gurgling drain lines mean that air is in the system and that’s not how it should be.
The air pockets create issues for the natural flow of the wastewater, and it gurgles and makes noises. As the air bubbles work their way through the wastewater to the surface to be released, you hear unusual sounds.
A toilet commonly makes these telltale gurgling noises after flushing. But gurgling noises could also be heard in any of your other draining fixtures. This is likely an earlier sign of developing issues, so it’s a livable situation at the moment that could turn into *worser things* the longer it goes on.
3. Recurring Back-Ups
When your drain pipes are misaligned or not smooth on the inside due to compromise, things can get stuck more easily. This could be a larger object that your toddler decided to flush down the toilet for fun. It could also come from various debris getting caught and building up in that particular spot because there is a catching point.
Tree roots are a very common cause of recurring backups because they infiltrate the drain lines to get to the water source. What happens is that you have a blockage, and the plumber comes out to snake the line or uses a rotary cutting tool (aka a Roto-Rooter kind of thing) to clear the lines.
This works for a little while, but then the roots grow back and you need another visit from the plumber.
Sometimes people live with this for a while, thinking they can simply get the drain lines “roto-rooted” each time it happens. But after you’ve done that several times, and paid the plumber to clear it over and over again, at some point, you may decide it’s worth it to finally repair the lines once and for all. Repeated rotary tool use can also thin cast iron lines and eventually lead to a full collapse of the pipe.
I 100% guarantee you that drain line back-ups tend to happen at the *most inconvenient* times. So if you’re having this issue repeatedly, it’s likely time to get it handled more permanently.
4. Smells
This one is not very common and seems harmless but smells coming from your drain lines can be dangerous. If you smell *funny stuff* coming from your drains, it could be coming from one of two places:
- Sewer gas due to faulty P-trap function or poor connections, or
- The stinking stuff that is stagnating in the ground under your home.
Either one is a bit of an *ewwww gross* situation and not a nice living environment. More importantly, sewer gas is not meant to be breathed in. It can make you sick. So if you’re *smelling smells*, then you need to get your drain lines looked at for leaks sooner rather than later.
Ways that Under-Slab Plumbing Leaks Can Get Repaired
Clearing blockages, repairing failure points, and making your under-slab lines drain properly can be handled in a few ways. There are short-term solutions, i.e. quick fixes, and there are more permanent repair options. We’ll break them down separately.
Short-Term Under-Slab Leak Solutions
Some solutions are more like band-aids. You might deal with the immediate problem of the drain issue (or should I say “not draining” issue?), but it’s only a temporary fix if you truly have a degrading, cracked, broken, or separated drain line and not a standard clogged line.
These options can sometimes resolve the issue of leaking or compromised drain lines in the short term:
- DIY with “Drano or Liquid Plumber-like” chemical
- DIY or call the plumber to clear the P-trap in the location of the offending drain issue
- Call the plumber to snake, jet, or *roto* the line and free the blockage
If you have a simple blockage or clog, these solutions will work both short and long-term. But if you have leaking or faulty lines, then these kinds of repairs will not permanently address the source of the problem and you may find yourself calling a plumber too often.
Long-Term Under-Slab Plumbing Leak Repairs
At some point, it might be smarter to actually fix the root cause of the problem by truly repairing or replacing the leaking lines properly. The following steps are needed and you may have choices at each stage. At any rate, these steps will correct your issue long term:
Step 1 – Locating the Leak
- Some plumbers may use a camera to visually locate the problem area, OR
- The plumber conducts a hydrostatic plumbing test to confirm the compromised lines, OR
- It may be necessary to do both to verify and isolate the issue.
Step 2 – Accessing the Repair Area
- A plumber breaks through your flooring and slab from the top down to repair lines, OR
- Plumbing failure point(s) is accessed by under-slab tunneling.
Step 3 – Repairing the Under-Slab Drain Lines
- The plumber repairs only the portion of the drain line that is broken or cracked, OR
- The entire drain line system needs replacement due to rusting cast iron material.
*Honesty Alert* Every plumber does things differently and it depends on what the actual problem is (cracked or separated PVC vs. degrading cast iron), so sometimes you have all these options and sometimes you don’t.
How You Access Plumbing Leaks Is An Important Decision
Now you know the most common signs of under-slab plumbing leaks and ways to address this issue. How the plumber accesses your under-slab leak to fix it is an important consideration. Breaking through your slab and under-slab tunneling are both viable options, but each option has its pros and cons.
Breaking through your slab can be quicker and cheaper but is also an intrusive mess that could require flooring replacement or moving out. Under-slab tunneling could be more expensive and take longer but is much more convenient and mess-free for homeowners.
We understand the stress and anxiety that comes with overwhelming repair issues that you don’t know much about. At Anchor Foundation Repair, we offer empowering education to help you through these times. After 40+ years in business, we want you to know all the info and options to make the best decisions for the home you love.
For a deeper dive into the advantages and disadvantages of your options to access plumbing leaks, we’ve got an article for that: Under-Slab Tunneling vs. Breaking Through Your Slab (Pros and Cons).