Don't Buy a Money Pit: The Five Structural Issues That Sink Houses

TLDR

In fifteen years I have bought over a hundred derelict houses. Ninety-nine percent of the structural problems I saw come down to five issues: cracked foundations, sloping floors, squishy floors, rotted walls, and a collapsing roof. They stack on each other like Jenga. The load starts at the peak of the roof and runs all the way down to the footings. Pull any block out and everything above it is compromised.

Table of Contents

• The Jenga Rule
• Issue One: Cracked Foundations
• How Water Destroys Foundations
• Stop the Bleeding First
• Issue Two: Sloping Floors
• When to Walk Away

The Jenga Rule

A house is a tower of load. Roof pushes down on walls. Walls push down on the floor system. Floor system pushes down on the foundation. Foundation pushes down on the footings. Footings sit in the dirt.

Pull any block out of that chain and everything above it drops or tilts or cracks. That is why the cheapest structural problem to miss is the one at the bottom.

Ninety-nine percent of the structural problems you will see on a house come down to five issues:

1. Cracked foundations
2. Sloping floors
3. Squishy floors
4. Rotted walls
5. Collapsing roof

They are all connected. A footing issue causes a foundation crack, which causes a floor slope, which causes walls to rack, which stresses the roof. You cannot fix one without understanding the rest.

When you understand how the tower works, you stop overpaying for fixes and you stop missing the issues that matter.

Issue One: Cracked Foundations

When I say foundation, I am really talking about two things: the footing, which is the concrete pad in the ground, and the stem wall, which is what sits on top of the footing and supports the floor above. The stem wall could be blocks, a solid poured wall, or old brick.

Two main rules govern a footing, both in the code book:

Water destroys even a code compliant foundation over time. There are three ways water gets at your footings: negative drainage, pooling, and saturation.

Negative drainage is when the grade of the yard pushes water toward the house instead of away.

Pooling is usually condensation from an hvac system. Window units dripping down the side of the house. Central HVAC condensation lines that do not run far enough away from the foundation.

Saturation comes from missing or broken gutters. Water pours over the side of the roof, hits the dirt next to the house, and saturates the ground right where your footings sit.

Common Mistake

People gut-rehab the interior and never touch the gutters. Two years later the foundation moves and the fresh drywall cracks across every room. You fixed the symptom and left the disease.

How Water Destroys Foundations

Water does not just run on top of the ground. One of the most expensive lessons I learned was on a house where we had done everything: tiered retaining walls, advanced gutter systems, regrading. Water still got in.

We were digging a trench in the back yard for a plumbing line, completely unrelated. One of my guys calls me over. I put my head down in the hole and I can hear water running underneath us.

A hill works like a sponge. When it rains, the hill saturates. The water still has to flow downhill, but it flows inside the hill. So there was an underground stream running through the slope, and my house was sitting in the middle of that stream like a rock. And you know what happens to a rock in the middle of a stream.

First lesson: do not buy houses on hills. I will not do it again. But if you already own one, here is how you stop the bleeding.

You let the water in. Sounds crazy. Here is how it works:

1. Water hits the outside of the foundation wall.
2. It goes through the wall, hits a moisture barrier on the inside.
3. Barrier drops the water into a French drain cut into the floor.
4. French drain runs into a sump pit in the crawl space or basement.
5. Sump pump pumps it out, joining the gutter system, away from the house.

Other sources of water under the house: plumbing leaks, condensation lines that dump inside the crawl space instead of outside. Find them. Fix them. The ground under your house cannot stay wet.

Stop the Bleeding First

There are three steps to fixing any structural issue in order:

1. Stop the bleeding. Find the water source and kill it.
2. Do the structural repair.
3. Cosmetic.

Skip step one and step two gets undone. I have seen people pour new concrete piers into a flooded crawl space and act surprised when the footings sink six months later.

Pro Tip

Before any structural contractor gets paid, the water source has to be dead. Gutters working. Negative grade corrected. Condensation lines running away from the house. If the crawl space is still wet when the structural work is done, the structural work will fail.

Fixes for the three water sources:

Once the bleeding is stopped, you deal with the repair itself. There are two ways to repair a failing foundation. You can lift the house in sections, pull the bad foundation, and pour a new one in five to ten foot chunks. I have done whole houses that way. Or you can install helical piers, which auger into the ground below the footing and jack the house back to where it belongs.

Both are expensive. Understanding which one fits your situation is what keeps contractor pricing honest.

Lack of knowledge is what gets you exploited. Study the fix before you buy the house.

Issue Two: Sloping Floors

Sloping floors come from a different idea than most new buyers understand. There are actually two foundations in most houses. The exterior foundation, which is what everyone thinks of, and the interior foundation, which is a pier and beam running down the middle of the crawl space.

The floor joists span from the exterior foundation to the interior pier and beam. If either side sinks, the floors slope.

Three shapes of sloped floor:

• Middle hump. Exterior foundation sank, interior pier stayed put. Water hit the outside.
• Middle dip. Exterior stayed solid, interior pier sank. Water saturated the crawl space.
• Roller coaster. Both foundations are fine but the span between them is too wide and the floor joists are bending under load.

The fix for roller coaster is adding another pier and beam in the middle to cut the span in half. The fix for hump or dip is addressing whichever foundation failed, which loops you back to the water issue.

Key Concept

Sloped floors are a symptom. Do not jack the floors flat without finding out which foundation failed and why. If you flatten the floor without fixing the source, the slope comes back within a year.

When to Walk Away

Three structural issues I have found that are not caused by water:

Undersized or no footings. Poor DIY building. I have poked through soil and found no footing at all. When it is not wide enough to sit on the soil, it sinks.

Deteriorating mortar in block or brick. An old-age issue. Tuck pointing fixes it. Simple but expensive.

Developer haste. This is the scary one. I bought a duplex once that was built on top of a pile of organic waste the developer had buried on the lot. Cut-down trees, loose dirt, construction scraps. Over time the organic waste did the organic thing and decomposed. The duplex ended up with twelve inches of settling from one corner to the other.

The fix for developer haste depends on what is underneath. You have to build on undisturbed earth. That means if a footing was dug and then backfilled, the soil at the bottom is now loose dirt, not compact ground. Fixing that right means excavating and compacting with proper equipment.

That deal cost me a lot of money. I am still dealing with it.

Walk-away triggers: multiple water sources, a hill behind it, visible cracks over a quarter inch, and floors that slope more than an inch over ten feet. That combination is a money pit. Price it for a full foundation rebuild or walk away. insurance will not cover any of this.

Remember, squishy floors come from wood structure issues, not foundation issues. That is a whole separate video and a whole separate article. Same idea though. Find the cause before you pay for the fix.

You can make a killing on houses that look like money pits, but only if you know exactly what is wrong with them. Knowledge is the thing that turns a bad house into a great deal.

FAQ

How do I tell if a crack in a foundation is structural or cosmetic?

Hairline cracks under a quarter inch are usually cosmetic settling. Cracks over a quarter inch, stair-step cracks in block, or cracks that are wider at the top than the bottom are structural. If you see any of those, get a structural engineer out before you write an offer.

Should a first-time flipper even look at houses with foundation issues?

You can, if the price already reflects a full foundation fix. Most new buyers are not priced correctly and end up eating the fix out of their margin. If you are new, start with houses where the foundation is clearly intact and learn to spot what you are looking at over the first few deals.

Is a French drain something I can DIY?

Yes on small exterior French drains behind a short retaining wall. No on interior French drains that tie into a sump pit. Interior work involves cutting concrete, running drain to pump, and pumping to the exterior system. Get a basement waterproofing specialist for that.

Do I need a structural engineer on every walkthrough?

No. You need a structural engineer when you see sloped floors over an inch, visible cracks wider than a quarter inch, or bowing walls. For routine due diligence, a good inspection plus your own walkthrough knowledge is enough.

What is the fastest red flag to spot on a walkthrough?

Doors that will not latch, gaps between the trim and the wall, and cabinet doors that swing open on their own. Those three tell you the house has moved. Your job is to find out why and how much.