Foundation cracks: which ones HUD guidance treats as serious, and what to do
By Dan Whitlock, Home Projects Editor · Updated October 2026
HUD’s Residential Rehabilitation Inspection Guide describes shrinkage cracks in concrete block foundation walls as rarely serious, while horizontal or sweeping cracks are potentially serious because they suggest the wall is being bent. For large differential settlement it advises the help of a structural or soils engineer. This page cannot tell which kind you have; a licensed engineer can.
What people usually report
Hairline vertical cracks in a poured wall, stair-step cracks along block mortar joints, a horizontal crack partway up a block wall, cracks that leak after rain, or cracks that seem wider than last year, sometimes with doors or windows upstairs starting to stick.
What official sources say this can mean
These are possible causes listed in published guidance. They are not a diagnosis of your home; only an inspection can tell which, if any, applies.
- Drying shrinkage of concrete block walls, which HUD says usually forms in the first year, in the middle third of the wall, and is rarely serious. (HUD)
- Settlement, which HUD says produces cracks that taper, largest at one end, often at corners and openings and following a rough diagonal along mortar joints. (HUD)
- Horizontal or sweeping cracks from improper backfilling, vibration from heavy vehicles near the wall, or swelling or frost heaving of water-saturated soil against it. (HUD)
- Soil changes beneath the footings: consolidation, shrinkage from tree roots drawing moisture, swelling from poor drainage, frost heave, or a changing water table. (HUD)
- Thermal and moisture movement in above-ground masonry, which HUD says often causes only cosmetic problems. (HUD)
Signs official guidance treats as structural
- HUD inspection guidance calls horizontal or sweeping cracks in block or concrete foundation walls potentially serious, because they indicate the wall carrying the house is bent or broken.
- It describes large differential settlement, and settlement that keeps moving, as more serious, and advises seeking the help of a structural or soils engineer.
- EPA moisture guidance also says that where water damage may be affecting a building’s structural integrity, a structural engineer or other qualified professional should be consulted.
- A licensed professional engineer is regulated by your state; NCEES lists every state engineering licensing board, where you can verify a license.
How to find out
Check it yourself
- Photograph each crack with a ruler or coin for scale, and date the photo.
- Note the direction: vertical, diagonal or stair-step along mortar joints, or horizontal. HUD guidance treats these differently. (HUD)
- Check whether the crack tapers (wider at one end) and whether its edges line up; HUD links tapering and offset cracks to settlement. (HUD)
- Track it over weeks with a crack monitor or pencil marks at the ends. Movement that has stopped and movement that continues lead to different repairs. (HUD)
- Check outside for the water sources HUD lists: broken downspouts and poor surface drainage near the cracked wall. (HUD)
When to call a licensed professional
- For horizontal cracks, bowing walls, cracks that are widening, or sticking doors and windows upstairs, a licensed structural engineer gives an independent assessment, separate from a repair contractor’s sales visit.
- For a crack that only leaks, a waterproofing contractor can seal it; ask them to confirm it is not structural first.
Official license lookups
Try this while you wait
Screening tools that help you gather facts before a professional visit. They do not diagnose anything and are no substitute for a licensed pro. As an Amazon Associate we may earn from qualifying purchases, and it never changes your price. Affiliate disclosure.
- Crack monitors and gauges on Amazon →
Lets you record whether a crack is getting wider over weeks, which is the question an engineer will ask first.
- Moisture meters on Amazon →
Shows whether drywall, wood trim, or framing is still wet, so you can tell an old stain from an active leak.
- Downspout extensions on Amazon →
EPA and CDC guidance both say roof water should drain away from the house.
Local help
We do not recommend or vet specific businesses. The official lookups above are the neutral way to check a license. The block below is advertising from our partner Angi.
Get quotes from local pros
Angi is a national marketplace for home services. You describe the job, and foundation contractors who work in your area contact you with their own quotes. Requesting quotes is free and you are never obliged to hire anyone.
Angi pays us a referral fee for a completed service request. The fee comes from Angi, not from you, and it does not change the estimates on this page.
What the fixes cost
- Basement Waterproofing cost calculator: $6,000–$18,000interior perimeter drain with a sump pump for a typical basement, professionally installed
- Concrete Slab cost calculator: $2,400–$6,000about 400 sq ft, 4 in slab, installed
- French Drain cost calculator: $2,500–$6,500about 100 linear ft, exterior yard drain, installed
Frequently asked questions
How serious are cracks in a foundation?
HUD’s inspection guidance separates them by type. It calls shrinkage cracking in concrete block walls rarely serious and minor settlement cracking structurally harmful mainly when long-term leaking damages the building. It calls horizontal or sweeping cracks potentially serious and advises a structural or soils engineer for large differential settlement. A licensed engineer is the person who can say which applies to your wall.
What does a concerning foundation crack look like?
In HUD’s guidance, the cracks that get the most concern are horizontal or sweeping cracks in a block or concrete wall, cracks that taper because one part of the foundation has settled more than another, and cracks where movement is continuing. Bowing walls and doors or windows that start sticking are commonly reported alongside them.
What is the average cost to fix a cracked foundation?
It depends entirely on the cause. Sealing a non-structural leaking crack with epoxy injection runs about $250 to $800 per crack, based on 2026 HomeGuide data, while structural repairs such as wall reinforcement or underpinning cost far more and need an engineer’s scope first. HUD notes older buildings with severe settlement can be very costly to repair.
Does homeowners insurance cover foundation crack repair?
Policies vary, and many exclude settling, cracking, and earth movement. Damage from a sudden covered event, such as a burst pipe, may be treated differently. Read the exclusions section of your policy and ask your insurer before repairs begin.
Related warning signs
Or see every guide in The Dry Home.
Sources
Official and technical guidance cited on this page, checked October 2026:
This guide summarizes published guidance from HUD, EPA, NCEES. Guidance can change and may not cover your situation; verify with the official source before making decisions. Not affiliated with any of these agencies or organizations. This page is general information, not medical, legal, insurance, or engineering advice, and it cannot diagnose a problem in your home.
Spot an error? Email a correction. Product links are Amazon affiliate links and the Angi block is a paid partnership; see our disclosure.