7 Structural Warning Signs at a Colorado Home Showing

Seven structural warning signs show up at a Colorado home showing before any inspector arrives: foundation cracks wider than a quarter inch, a heaved or sloped floor, doors and windows that bind, a bowing basement wall, water and grading problems, diagonal drywall cracks, and a porch, chimney or garage pulling away from the house. One sign alone means a question for the seller; two or more together mean a structural engineer inside the inspection window, at $400 to $800 for a site visit and letter in the Denver metro.

The companion post on the seven checks Colorado buyers skip covers the documents, tests and contract deadlines; this one covers what the buyer sees at the showing and what each repair costs.

Why Colorado homes move

Most of the Denver metro, from Aurora and Thornton through Lakewood, Littleton, Highlands Ranch, Parker and Castle Rock, sits on expansive bentonite clay that swells when wet and shrinks when dry, and the Front Range gives it both every year: a wet spring, a dry August, freeze-thaw all winter and sprinklers from April to October. Douglas County also maps steeply dipping bedrock, where foundations need engineered designs.

Heave pushes up from below and is the Colorado signature: a slab that rises, a floating wall whose gap has closed, a floor that humps. Settlement drops one corner when backfill compacts or water washes soil from under a footing. The engineer's letter says which one a house has.

1. Foundation cracks wider than a quarter inch

Hairline vertical cracks in poured concrete are shrinkage and appear in almost every Colorado basement. The cracks that matter:

• Horizontal cracks at mid-height on a basement wall: soil pressure pushing the wall in.
• Stair-step cracks in block or brick, following the mortar joints as part of the wall moves.
• Diagonal cracks that widen toward one end: differential movement.
• Cracks with offset edges, or with water staining or rust below them.
• Patched cracks that have reopened: the movement continued after the repair.

Look in the unfinished basement, the garage, the window wells and the exposed foundation outside; a crack that takes a quarter's edge is wider than a quarter inch. The post on whether a foundation crack means a Denver-area home has a structural problem shows the crack types with the repairs that match.

2. A heaved slab, a sloped floor or a closed floating-wall gap

Denver metro basement slabs float on the soil, untied to the foundation walls, and the framed walls in a finished basement float too: the framing hangs from the joists above with a 1.5 to 3 inch gap over the plate on the slab, so the slab can rise without lifting the house. Find that gap in the furnace room or behind a baseboard. A closed gap, a bowed bottom plate or a basement door that no longer clears the floor means the slab has heaved.

Upstairs, set a marble or a level on the floor in every room. A hump over a basement bearing wall is heave transferred through the posts; a slope toward one corner is settlement there. Soft spots over a crawlspace mean a joist or beam problem, and the crawlspace also gets checked for standing water and a vapor barrier.

3. Doors and windows that bind, and frames out of square

Open and close every door and window, closets included. On expansive soil doors bind in a wet spring and free up in a dry August, so note where the showing falls in that cycle. The signs that point past seasonal swelling:

• Uneven gaps around a door, wider on one side at the top.
• Doors that swing open or shut on their own, which means the frame is out of plumb.
• Doors rubbing the floor at one corner, or a strike plate that has been moved twice.
• Windows that bind on one side of the house only, over a crack in the foundation below.
• Fresh paint and new trim on one door frame only, hiding a shimmed or planed door.

4. A bowing or leaning basement wall

Sight along each basement wall from one end. A wall that bows inward at mid-height with a horizontal crack along the bow is being pushed by wet clay; a wall that leans in at the top has lost its tie to the floor framing. In a finished basement, check the furnace room and closets where the wall is bare, and look for a bulge in the drywall or a baseboard pulled away.

Denver metro repair costs: carbon fiber straps at $500 to $1,000 each for a wall moved under 2 inches; steel anchors or braces at $5,000 to $15,000 per wall for more; excavation and rebuilding from $25,000. The drainage outside gets fixed at the same time, or the wall moves again.

5. Water, grading, downspouts and sprinklers

Water is what makes bentonite move, so the lot gets checked first: a grade that drops 6 inches in the first 10 feet from the foundation, downspout extensions at least 5 feet out, window wells with drains and covers, and no sprinkler head hitting the foundation wall. Irrigation is the largest source of foundation wetting in a dry climate, and a lush flower bed against the house is a warning, not a feature.

Inside, look for efflorescence, the white mineral bloom that means water has passed through the concrete; a tide line on the wall; rust on the furnace base; a sump pit with a working pump; and new paint on the lower 3 feet of a basement wall. Efflorescence alone is a $2,000 to $6,000 regrading and extension fix. A basement that takes water every spring is a $10,000 to $25,000 interior drain and sump job. The posts on hidden water damage signs for Colorado buyers and Denver flood zones and drainage cover the water side.

6. Diagonal drywall cracks above doors and windows

Diagonal drywall cracks from the corners of door and window openings, repeated in the same direction across several rooms or paired with a sticking door below, are frame movement. So are nail pops in a line along a joist and a crack the full length of a ceiling.

One Colorado crack is not structural: a gap between the ceiling and the top of interior walls that opens in winter and closes in summer is truss uplift, the roof trusses arching as the cold attic dries the top chords, and a crown molding detail fixes it. A gap that stays open all year or sits at the top of an exterior wall goes on the engineer's list.

7. A chimney, porch, stoop or garage pulling away from the house

Walk the outside and look at every place something attaches to the house. Porches, stoops, patios and garage slabs in the Denver metro sit on backfill placed when the house was built, and backfill settles. A stoop that has dropped an inch from the threshold is common and is a $1,500 to $4,000 foam or mudjacking lift. A chimney leaning away from the house, a deck ledger with a gap behind it, or a tipped retaining wall is movement under a load-bearing element and goes to the engineer.

Two non-structural items belong on the same walk. Colorado hail season runs May to September, and the roof's age and material decide whether an insurer will bind the house; Federal Pacific and Zinsco panels in 1950s to early 1980s homes get flagged by every inspector and most insurers. Both go in the same inspection objection as the foundation findings, and the list of inspection red flags that kill Denver home sales gives the repair numbers.

When to call a structural engineer, and what it costs

Call the engineer when two or more signs appear together, when any crack is horizontal or wider than a quarter inch, when a floating-wall gap has closed, or when the seller discloses a past repair. The inspector reports what is visible; only a licensed Colorado professional engineer signs the letter that says what it means and what fixes it, and lenders, insurers and the next buyer all read that letter.

Piers, wall bracing and drainage are done by contractors who specialize in structural foundation services, and the buyer asks for a transferable warranty on the work. A home with a documented pier repair, an engineer's sign-off and a transferable warranty is a better buy than a home with an unexplained crack: one has been diagnosed and the other has not.

Using the inspection objection deadline for a structural finding

The Colorado contract's inspection objection deadline falls 7 to 10 days after contract on most Denver metro deals, and the engineer has to visit and write inside that window, so the buyer books the engineer the day the inspector reports the trigger. Before the deadline the buyer delivers one of three things in writing: an objection asking for the repair, a request for a credit equal to the engineer's number, or a termination with the earnest money returned. After the deadline the earnest money, 1% to 2% of the price, stays with the seller.

Ask the seller these questions through the listing agent and get the answers in writing:

1. Has the foundation ever been repaired, stabilized or piered, and by whom?
2. Is there an engineer's report, a soils report or a permit for that work?
3. Is the repair warranty transferable to a new owner?
4. Has water entered the basement or crawlspace, and when?
5. What drainage or grading work has been done?

Colorado law requires the seller to answer known structural and water history on the Seller's Property Disclosure, and a builder of a new home has to give the buyer a soils report and an expansive-soils summary before closing. An FHA or VA appraiser who sees active foundation movement calls for an engineer's certification before the loan funds. Mike Oswald, VP of Mortgage Lending at Rate, NMLS 261003, Equal Housing Lender, walks Colorado buyers through what the appraiser will require on a home with a structural finding. You are free to use any lender. The Colorado home financing guide and the Colorado mortgage pre-approval guide cover the loan side.

The signs above are heaviest in the south metro clay and bedrock belt, so buyers touring Highlands Ranch, Castle Rock and Parker homes walk the basement first, and the pre-offer home checks Denver metro buyers run before the inspection list the rest of the showing walk.

Where to go next

• The Colorado Home Buyer's Guide
• How the Kenna Real Estate Group helps Colorado buyers
• First-time home buyer guide for Colorado
• Closing costs for Colorado home buyers
• Kenna Real Estate Group agents
• Search every home for sale in Colorado

Talk to the Kenna Real Estate Group

The Kenna Real Estate Group at Keller Williams DTC walks the basement and the lot with buyers at the showing, writes the inspection deadline long enough for an engineer's visit, and negotiates the repair, the credit or the exit when the letter comes back. Call or text 303-955-4220. A live person answers. Not a robot, not a phone tree. Start the search: search every home for sale in Colorado.