Home Inspectors' Guide to Foundation Failure: 3 Areas to Check

Home inspections are a tough gig, you get paid to find problems to reassure clients real estate is a healthy and viable investment.

Emotions are high, your client is going through a complex whirlwind of feeling that could easily match any Shakespeare dramedy.

Alas! This abode doeth sinketh into the mire, soil doeth expand

Lucky for you, the signs and symptoms of foundation failure are not that sophisticated or as difficult to decipher as iambic pentameter.

In this article, we are going to walk you through the steps of how to diagnose foundation failure by inspecting 3 major areas of a home:

• Crawlspace
• Interior
• Exterior

The goal of this article is to equip you, the home inspector, to be a genuine Sherlock Holmes of foundation settlement and foundation heave.

Crawlspace Inspection for Foundation Failure

Crawlspaces are a byproduct of raised foundations, whether they’re post and pad, cripple wall, or stem wall foundations.

Check out our article: Top 4 Crawl Space Problems & Solutions .

Crawlspaces need to be maintained and examined during real-estate inspections to ensure the home is safe, viable, and secure.

Crawlspace section to pay special attention to are:

Sill Plate

A sill plate (also referred to as a sole plate) is treated wood that is utilized around the entire perimeter of a raised foundation to deter humidity, upward draft, and insects from penetrating the crawl space.

A sill plate is a major player in the structural integrity of a home, if one section is compromised it can result in sagging floors and exert undue stress on the home.

Inspect the sill plate for rotted, split wood and sections where the sill plate does not connect flush with the foundation.

Signs you might encounter sill plate issues are:

• Termites
• A particularly damp crawlspace
• The sill plate was not properly treated before being utilized

Crack s, hole s, and gashes in the stem wall and/or footing need to be patched right away as moisture can seep into the compromised concrete and rust the rebar, causing it to expand.

Rusted rebar can exert as much as 9000psi of pressure. We’ve seen footings in the field with entire concrete sections chunked off due to rust pressure.

Moisture and Wet Spots

Wet spots are indicative of two primary causes: a leak (plumbing, sprinkler, etc.) and poor insulation/water mitigation.

Either way, sitting water can cause serious problems, such as settlement and heave, which sink and raise the foundation respectively, exerting undue stress on the home.

As a general rule of thumb, the higher the moisture spot on the stem wall, the bigger and badder the potential problems.

Sluff, Spalling, & Efflorescence

Where there is moisture, you are bound to see sluff, spalling, and efflorescence, all signs of:

• Bad drainage
• Poor water mitigation

Efflorescence can be identified as a white, patchy salt calcification generally found on concrete, brick, and masonry of the stem wall.

Post & Pads, Joists and Girder Beams

You want to ensure the posts and pads are up to code, which is six feet on the center.

If the posts and pads span distances longer than six feet, this exerts a tremendous amount of stress on the girder beams which can cause:

• Bowed floors
• Squeaky floors
• Boingy floors (like you’re walking across a wooden African drum)

You want to ensure that the posts and pads are securely snug between the subfloor and gradient.

You also want to look for warped, split, and rotting wood.

Everything that should be attached needs to be attached (for example, the post should be connected to the pad and the girder beam), especially homes that have been seismically retrofitted.

The same is true after a seismic retrofit: check that every connection the retrofit added is secure.

We work hand-in-hand with the Earthquake Brace + Bolt Program to ensure the job gets done right.

Interior of Home Inspection for Foundation Failure

Foundation failure due to settlement and heave exerts a tremendous amount of pressure on a structure’s foundation, which fractures out into the wooden bones of the home and then into the hallways, bedrooms, and kitchens.

Homeowners want to take pride and joy in their homes, which can be difficult when there are sloped funhouse floors, unsightly drywall cracks, and huge gaps between the baseboard and floor.

Cracks often are not just a cosmetic issue but point to lurking problems underneath.

Drywall Cracks

Drywall cracks can be indicative of foundation failure. Look for:

• Cracks that are thicker than a quarter-inch
• Cracks jutting out from window/door frames
• Bulging and bowing walls
• Pulling drywall tape

Sticking Doors & Windows

Sticking doors & windows can be a major issue.

Go throughout the house and open and close all of the doors. Doors and windows that are difficult to open and off-center/ out-of-frame are concrete signs that there are foundation problems.

Sloped Floors

Sloped floors are not always pronounced, but some hallways I’ve walked down have definitely given me vertigo.

A good test is to take a marble or ball bearing and place it on the floor in different areas of the room. Watch where the ball rolls and how fast.

While you are checking for floor slope, you can also look for gaps between the baseboards and floor and floorboards pulling away from each other.

Slab Cracks

Look for cracked slab in the garage or cracked tile in the kitchen and bathrooms. This can also result in bumps in the carpet and other tripping hazards.