Sticking Doors and Uneven Floors Edmonton: Why It Often Means Foundation Movement
Quick Answer: Sticking doors and uneven floors in Edmonton point to foundation movement when the pattern is seasonal, slope exceeds 1% (1 inch per 8.3 feet), and multiple rooms tilt the same direction. Joist sag is under 1/4 inch, isolated, and ignores Edmonton’s freeze-thaw calendar. A marble test sorts cases.
Most Edmonton homeowners catch foundation movement through doors before they catch it through cracks. The latch stops catching. The bedroom door drags. You start hipping it shut. The question is whether that means the foundation has moved, or whether wood swelled up after a wet week.
The answer depends on the pattern more than the symptom.
A door that scrapes its frame or a floor that rolls underfoot is rarely a one-off quirk, it is usually one piece of a larger story your house is telling. Before we dig into the why, it helps to see how settlement symptoms fit into the bigger picture of Edmonton foundation trouble so you know which warning signs deserve a closer look.
Is It the Foundation, or Just Wood Movement?
Wood expands across the grain when humidity rises and shrinks when it falls. An Edmonton interior door can gain or lose 1/16 inch of width between February (very dry, indoor relative humidity often under 25%) and August (humid, RH near 50%). That alone is enough to make a door start dragging in summer and clear up in winter.
Foundation movement does the opposite. Doors typically stick in late winter when frost heave is at maximum, then again in late spring as clay rehydrates and the foundation settles back. The seasonal pattern is the tell.
Edmonton Seasonal Sticking Pattern
- December to February: Doors stick from frost heave lifting the perimeter footing unevenly. Worst in homes on solonetzic clay (Millwoods, Glastonbury, Clareview).
- March to May: Doors stick from rapid clay rehydration and differential settlement as the ground thaws. Often worse in newer Terwillegar and Windermere builds on disturbed glacial till.
- June to August: Mostly wood swell from interior humidity rising. Foundation contribution low unless drainage is bad.
- September to October: Doors that stuck in spring start clearing up as clay equilibrates. If they don’t clear up, the foundation likely did not return to baseline.
If a door is fine in October and sticks in February, that is a foundation conversation. If a door is fine in February and sticks in July, that is a humidity conversation.
Does the Marble Test Actually Work?
Mostly, yes. Place a marble, a ping pong ball, or a glass jar lid on different parts of the floor. If it rolls consistently toward one corner or one wall in multiple rooms, the foundation is tilting in that direction. If it rolls in one spot but stays put in the next room, you are looking at localized joist sag, not foundation movement.
The marble test is not a slope measurement. It is a yes/no on whether the slope is steep enough to overcome rolling friction, which kicks in around 0.5% slope (1/2 inch per 8.3 feet). That is sensitive enough to catch the early stage of differential settlement, which is exactly when intervention is cheapest.
20-Minute DIY Slope Map
You need a 4-foot level, a tape measure, and a pencil. Lay the level flat on the floor with one end against a baseboard. Lift the high end with the tape measure until the bubble centres, and read the gap. Repeat every 4 feet across every room. Sketch the numbers on a graph paper plan of your floor. Anything over 1/4 inch in 4 feet (a 0.5% slope) is past the rolling-friction threshold. Anything over 1/2 inch in 4 feet (a 1% slope) is past the engineering tolerance for residential floors.
For more on confirming which direction the foundation moved, our guide on foundation settlement vs heave in Edmonton covers how to read which side dropped and which side rose.
What the Engineering Tolerances Actually Say
Most homeowners do not know there are real numbers behind “the floor seems uneven.” There are.
Residential Floor Slope Tolerances
The widely-cited engineering standard for differential foundation settlement is 25 mm (1 inch) total and 12 mm (1/2 inch) differential between adjacent foundation elements, per US Army Corps of Engineers and most concrete-structures manuals. Floor tilt over 1% is the threshold at which a trained inspector will consistently notice the slope. Deflection over L/360 (about 1 inch per 30 feet) starts to crack drywall and stress framing.
For National Building Code of Canada 2025 residential design, construction tolerance is generally 1/8 inch per 10 feet (0.1%). Once a floor exceeds that, the house is no longer behaving as designed. Movement of 1% or more is where you start seeing visible cracking, sticking doors throughout the floor, and uneven windows in the room.
The practical upshot: if your slope is 1/8 inch in 4 feet, that is borderline normal. If your slope is 1/2 inch in 4 feet, the foundation has moved enough to need a professional look.
Joist Sag vs Foundation Movement
Edmonton has plenty of 1960s and 1970s bungalows in mature neighbourhoods (Glenora, Garneau, Strathcona, Belgravia) where the floor joists themselves have crept downward over 50 years of dead load. That is a separate problem from foundation movement, and it is fixed differently.
How to tell them apart:
- Foundation movement: Multiple rooms tilt the same direction. Doors stick on perimeter walls. Floor slope continues right up to the foundation wall. Often pairs with exterior cracks visible on the foundation or a sloping driveway.
- Joist sag: One room is bowl-shaped, dipping in the middle. Doors stick on interior walls. Slope is greatest under the centre beam, smallest at the perimeter. Often pairs with a basement support post that has crushed shims under it or a beam that looks bowed when sighted along.
If a bedroom slopes 1/2 inch from the centre of the room to the outside wall, that is foundation. If a bedroom slopes 1/2 inch from the centre of the room to the doorway (an interior wall), that is joist. Both are fixable, but the fix is different.
Tim Phillips, Alberta Foundation Repair: “First thing I ask is when the door started sticking. If they say last winter, I know we are likely looking at frost heave or settlement, and when I inspect the foundation on site I can read which one it is. If they say last August in the heat, I usually tell them to put a dehumidifier in the basement before I quote anything. We do not need to bill a foundation repair for a humidity problem.”
When Sticking Doors Mean Call This Week, Not Next Year
Most sticking-door situations are not urgent. The rare ones that are share a few patterns:
- Doors started sticking suddenly, not gradually. Foundation movement that fast suggests a drainage failure, a frost-jacked column, or active settlement under a recent excavation nearby.
- Multiple doors stuck and at least one new visible crack appeared in the same season. The slope shift was enough to stress framing.
- You can see daylight under a door that closes properly, with a gap of 1/2 inch or more on one side. That is differential settlement that has already passed engineering tolerance.
- Doors sticking is paired with a bowing basement wall on the same side of the house. The wall and the floor are moving together. See our bowing basement wall guide for what that combination usually means.
- You bought the house recently and the prior owner did not disclose. Document the slope numbers and dates before contacting the agent or seller’s broker. Our buying a house with foundation problems guide walks through next steps.
For broader symptom triage across multiple signs, our how to tell if your foundation needs repair hub article maps 12 symptoms across 3 severity tiers.
Frequently Asked Questions
How much slope is too much for an Edmonton house floor?
Over 1% (1 inch per 8.3 feet) is past the engineering tolerance for residential floors. Most homeowners notice 0.5% slope (1/2 inch per 8.3 feet) on a marble test. Anything between 0.1% and 0.5% is in the normal range for an older Edmonton home and is not, by itself, a foundation emergency.
Do sticking doors always mean foundation problems in Edmonton?
No. Summer humidity swells interior doors enough to drag, especially in homes with new flooring or replacement doors that were not climate-equalized before installation. The foundation conversation starts when doors stick in winter (frost heave) or in spring (post-thaw settlement) and ease up in fall, following Edmonton’s clay-soil moisture calendar.
What does it cost to diagnose sticking doors in Edmonton?
Nothing. A free on-site visual inspection with Tim covers the slope walk-through and door pattern check. Tim inspects the foundation and identifies the cause of the movement, the settlement zone, void, or saturated layer driving it, and gives you an honest opinion at no charge.
Sources
- US Army Corps of Engineers. Foundations in Expansive Soils, TM 5-818-7. Department of the Army. Allowable settlement tolerances. Link
- National Research Council Canada (2025). National Building Code of Canada 2025, Division B, Part 9 (Housing and Small Buildings). nrc.canada.ca
- Skempton, A.W. and MacDonald, D.H. (1956). The Allowable Settlements of Buildings. Proceedings of the Institution of Civil Engineers. Foundational reference for the 1/300 angular distortion threshold widely used in residential settlement evaluation.
- Caltrans (2021). Geotechnical Manual, Shallow Foundations Section. California Department of Transportation. Link
- Alberta Geological Survey. Surficial Geology of the Edmonton District. Open File Report Series. Link
Get a Slope and Door Walk-Through in Edmonton
If doors started sticking last winter and your marble test confirms a slope, the question now is what is driving the slope and how fast it is moving. Tim will do a free visual walk-through, measure the slope with you, and tell you honestly whether you are looking at a foundation conversation or a humidity conversation.
Alberta Foundation Repair covers Edmonton and surrounding areas. (519) 732-1964
