If you own a condo in Alberta and you spot mould, the first question is always the same: who pays to fix it? Is it on you, the condo corporation, or someone’s insurer? I run an inspection and remediation company, and I’ve seen neighbours go from friendly hallway chats to full-blown disputes because nobody pinned down where the leak started or what the bylaws say. The good news is that Alberta has a clear legal framework. The trick is knowing where your unit ends, where common property begins, and how your bylaws and insurance plug the gaps.
Why Mould Responsibility Gets Messy
Mould is a symptom of one thing: moisture that wasn’t managed in time. In condos, moisture sources cross boundaries. A pinhole leak in a unit line can spread into common walls. A failed roof membrane can drip into the top floor units. A balcony is often common property with exclusive use rights, yet the sealant on the balcony door might be your responsibility under the bylaws. Because different players control different pieces, responsibility hinges on three things: unit vs. common property lines, what your bylaws assign, and how insurance responds to the loss.
Unit Vs Common Property
Alberta’s Condominium Property Act treats common property as everything in the building that isn’t part of an individual unit as shown on the condo plan. Walls, roofs, exterior windows and doors can be either part of the unit or common property depending on the plan and bylaws. Exclusive-use areas like balconies and patios remain common property, even though a specific owner gets the everyday use. Who repairs or maintains those spaces is usually spelled out in your bylaws or rules. If your plan or bylaws redefine what’s inside the unit boundary or label some items as managed property for the corporation to maintain, that directly affects who fixes moisture sources and who pays for mould cleanup.
What The Board Must Handle
The condo corporation, through the board, is responsible for maintaining, repairing, and managing common property and any managed property assigned to it in the bylaws. That includes addressing leaks and moisture problems in the roof, exterior walls, shared plumbing stacks, common ventilation systems, and building envelopes. If mould grows because of a failure in common property, the corporation is expected to stop the leak, remediate the affected common areas, and coordinate access to affected units for repairs that relate to the common property failure. The corporation should also plan for these expenses through its reserve fund for long-term repair and replacement of common components so the building does not defer fixes that create bigger mould issues.
What Owners Must Handle
Owners are responsible for maintaining and repairing their units. That typically covers interior plumbing fixtures and hoses, appliances, shutoff valves, sinks, toilets, tubs, interior electrical, drywall and finishes, and any upgrades or improvements beyond the standard finish. If a fridge line cracks and soaks your floor, you’re usually the one who fixes the appliance, dries the unit, and handles mould remediation inside your unit. If the board can show the loss started inside your unit and you did not report or address it promptly, you can also face charge-backs under the bylaws.
Exclusive-use common areas are a common flashpoint. Many bylaws make owners responsible for day-to-day upkeep of balconies and patios, including sealants and surface finishes, while keeping the underlying structure as a corporation responsibility. If the failure is a maintenance item you were assigned to look after and it allows water into the building envelope, you can expect to be involved in paying for repairs related to the loss inside your unit and possibly the corporation’s deductible if the bylaws allow it.
How Insurance Works
Two policies typically respond to water damage and mould-related costs in a condominium setting: the corporation’s master policy and the unit owner’s policy. The Standard Insurable Unit Description is the blueprint that tells insurers what parts of the unit the corporation insures by default and what portions are the owner’s job, especially for upgrades. Your personal policy should cover your unit finishes that are not part of the SIUD, plus your contents, additional living expenses, and liability.
When an insured peril triggers damage that leads to mould, the corporation’s master policy can respond for common property and any parts of units the corporation is required to insure under the SIUD. If the loss originates inside a unit or in an exclusive-use area, many Alberta bylaws create absolute liability for the owner for the corporation’s deductible up to a cap, typically not more than 50,000. If your bylaws do not contain that type of charge-back language, then the corporation usually must show negligence to recover the deductible from an owner. This is why owners should carry unit policies that include loss assessment or deductible coverage matching the corporation’s deductible exposure. If the master policy does not respond because the event is not an insured peril or due to exclusions, expenses are allocated based on the repair responsibilities set out by the plan and bylaws.
When Bylaws Decide It
Bylaws and your condo plan are the tiebreakers. They often clarify where the unit boundary sits, whether exterior windows and doors are part of the unit or common property, and which elements inside a unit are treated as managed property. They also set out charge-back authority for the corporation, including when an owner can be billed for costs or deductibles related to losses starting in that owner’s unit or exclusive-use area. If the bylaws are crystal clear, disputes are rare. If they are vague, arguments start, insurers hesitate, and mould sits longer than it should. Ask the manager for the current bylaws, the condo plan, any standard insurable unit description, and rules about exclusive-use areas. Those four documents are your map.
Who Pays In These Scenarios?
Every building is different, but these patterns repeat in Alberta condos. Always confirm against your specific bylaws, plan, SIUD, and insurance policies.
| Scenario | Who Usually Acts | Why It Falls There |
|---|---|---|
| Roof leak drips into top floor units | Corporation repairs roof and remediates common property. Units handle unit finishes not insured by the master policy. | Roof is common property. Master policy may respond for common property. Owners claim unit finishes through personal policies. |
| Leaking dishwasher line inside a unit | Owner fixes appliance and remediates the unit. Corporation addresses any common areas impacted. | Loss originates inside the unit. If the bylaws allow, owner may be charged the corporation’s deductible up to the cap. |
| Balcony door seal fails and water enters wall | Depends on bylaws: owner often maintains sealant, corporation handles structural envelope issues. | Balcony is usually common property with exclusive use. Maintenance vs. structural obligations split by bylaws and plan. |
| Chronic humidity from shared ventilation issues | Corporation corrects ventilation system and coordinates remediation. | Shared ventilation is common property. Ongoing moisture is a building system issue. |
| Pipe burst in a common riser inside a wall | Corporation repairs riser and common walls. Units remediate interior finishes per SIUD and policy. | Risers serving multiple units are usually common property. |
| Owner upgrades with steam shower causing humidity | Owner remediates unit and may be liable for adjacent damage. | Upgrade beyond SIUD is owner’s risk. If it causes damage, liability can follow under bylaws or negligence. |
How To Report And Document
Water plus time equals mould. Your best defence is speed and documentation. Start by taking photos and short videos of any visible water, staining, bubbling paint, peeling baseboards, or musty odours. Capture a wide shot, then close-ups, and include a ruler or coin for scale. Add a quick note with the time and date. If you have a simple humidity meter, grab readings in the room and compare to other rooms.
Report in writing to the property manager or board right away if you suspect common property is involved. If you rent your unit out, notify your tenant to contact you and the manager in writing, not just by phone. If you believe the source started inside your unit, contact your own insurer at the same time as the manager. Provide your notes, photos, and a description of when you first saw signs. The manager will ask about the location relative to common elements and may arrange access for contractors or adjusters.
Before anyone starts demolition, confirm with the insurer and the manager what emergency steps are allowed. Usually you can shut off water, extract standing water, remove loose wet materials like area rugs, and set up drying equipment. Cutting out drywall or removing cabinets without approval can create insurance headaches. At the same time, do not sit on active leaks. Water should be stopped immediately and wet materials dried within 24 to 48 hours to reduce mould growth.
Prevention That Avoids Fights
A lot of condo mould calls we attend could have been avoided with simple maintenance. Replace braided supply lines to dishwashers and ice makers before they fail. Check caulking in showers and around tubs. Use the bathroom fan for at least 20 minutes after showers. Keep indoor relative humidity around 30 to 50 percent during the heating season. In winter, watch for window condensation and adjust humidity accordingly. If you have a storage room on an exterior wall, leave some space for air to move. Small actions like these are boring, but they are far cheaper than paying a corporation deductible because a three-dollar hose let go.
Renters Inside Condos
If you are a tenant in a condo, report water and mould to your landlord and the condo manager immediately and in writing. Your landlord is the unit owner and is responsible for unit repairs under the bylaws. The condo corporation will not deal with tenant-only communications for unit repairs in many buildings. If the issue involves common property, managers may coordinate access directly with you, but they will keep the owner in the loop. Tenants should not tear out drywall or perform remediation on their own. If the unit is unfit to occupy due to mould linked to a building failure, Alberta Health Services can get involved and issue orders. Document everything and keep copies of communications.
When To Call Inspectors
Call a qualified inspector or remediation contractor when you have any one of these: visible mould larger than a dinner plate, a musty odour that persists after drying, water that contacted wall cavities or insulation, or a leak that went on for more than 24 to 48 hours. In condos, containment and communication are key. We will coordinate with the manager, follow IICRC S520 practices, and set up proper containment and negative pressure so spores do not move into hallways or neighbouring units. If asbestos-containing materials are suspected in older buildings, do not start demolition until testing is complete. Alberta rules require an asbestos assessment before disturbing suspect materials, and we take that seriously for everyone’s safety.
What If The Board Or Insurer Says No?
Disagreements happen. Start with the documents. Ask for the condo plan, bylaws, the SIUD, and confirmation of what is common vs. unit property in the affected area. Provide your timeline and photos. Ask the adjusters to clarify coverage decisions in writing. If the loss clearly started inside your unit and your bylaws have an absolute liability clause, plan for the deductible to be charged back up to the cap. If the bylaws do not have that clause and negligence is not proven, ask the manager to explain why they believe a charge-back applies. For persistent disputes, Alberta’s Condominium Property Act includes dispute resolution options, and legal counsel who focuses on condos can cut through the noise. While that plays out, do not delay drying and containment. Proving a point while mould spreads is a lose-lose.
Practical Owner Checklist
I’m not big on paperwork, but in condo claims it pays off. Here is a quick approach that keeps projects moving and costs where they belong:
Read your bylaws and SIUD to know what parts of your unit you insure and maintain. Photograph water or mould right away. Email the manager and your insurer with the timeline and photos. Shut off water and arrange emergency drying within the permissions of the insurer and manager. Keep receipts for hoses, valves, and maintenance. Confirm in writing who is approving remediation, what is covered, and what deductible applies. Ask the manager to identify if the area is unit, common property, or exclusive-use common property. If health risk is suspected, ask about Alberta Health Services involvement. Once the source is fixed and mould is remediated, improve ventilation and humidity control to prevent a repeat.
FAQ
Is mould inside my unit always my problem?
Not always. If the moisture source is a common property failure like a roof leak or a shared pipe, the corporation typically handles the common property repair and may coordinate related remediation. Your unit finishes may be covered by either the corporation’s policy or your unit policy depending on the SIUD. If the moisture source is inside your unit, you usually handle it.
Can the corporation charge me its insurance deductible?
Yes, if your bylaws include an absolute liability clause that allows charging back when a loss originates in your unit or exclusive-use area, subject to a cap that is usually not more than 50,000. If the bylaws do not include that clause, the corporation often needs to show negligence to recover the deductible.
What counts as common property mould responsibility?
Think building systems and shared elements: roofs, exterior walls, shared plumbing stacks, common ventilation, hallways, parkades, and structural portions. If mould grows because those systems failed, the corporation typically acts on those areas. Your unit items and upgrades are generally your responsibility unless the SIUD and bylaws say otherwise.
Do I need permission to cut out wet drywall?
Get the insurer’s and the manager’s go-ahead first. You can stop the leak and start drying, but cutting out building materials before documentation can cause coverage problems and disputes. In older buildings, you also risk disturbing asbestos if you cut first and test later.
What if the balcony is mouldy?
Balconies are usually common property with exclusive use. Maintenance such as surface cleaning and caulking may be the owner’s job, while structural repairs sit with the corporation. Mould due to a failed balcony membrane or wall interface often triggers corporation action. Check your bylaws to confirm the split.
Do renters handle mould themselves?
Tenants should report issues to the owner and the manager in writing and then wait for direction. Owners are responsible for unit-level maintenance under the bylaws. Tenants should not perform demolition or remediation unless authorized. If there is a health concern and no action occurs, Alberta Health Services can step in.
Straight Talk From The Field
I have walked into plenty of units where a slow drip behind the dishwasher turned a small cabinet repair into a full kitchen tear-out. I have also seen top-floor residents blamed for ceiling mould that ultimately traced back to a roof penetration two floors up. The difference is almost always the paperwork and the speed of response. Alberta condominium bylaws decide the who, and the SIUD drives the insurance. If you are a board member, make sure your bylaws clearly set out repair responsibility and deductible charge-backs. If you are an owner, match your policy limits to the corporation’s deductible and keep maintenance up to date. And if water shows up, document, report, and dry fast. That is how you stop mould and stop disputes before they start.