Finding mould in a baby room is understandably alarming, and in Illawarra homes the combination of coastal humidity and common building types means it is not rare. The practical guidance is straightforward: if there is visible mould in the room where a baby sleeps, move the cot first, then investigate the source. For health questions about your baby, your GP or paediatrician is the right call. This page covers the building side of the problem, with local context for Illawarra homes. Our black mould guide explains how to interpret what you are looking at on walls and ceilings.
BLUF answer
Mould in a baby’s room warrants prompt action, not panic. Move the cot away from any visible mould, increase ventilation, and investigate the moisture source. Refer health concerns to your GP or paediatrician. For mould that covers more than a small patch, that sits behind walls, or that keeps returning after cleaning, a professional inspection is the sensible next step.
The NSW Health mould factsheet notes that people who are more sensitive, including young children, are advised to avoid direct contact with mould. And the Raising Children Network, home safety is a sound resource for paediatric health questions beyond the building issues covered here.
First-response steps (before you scrub anything)
When you first spot mould in a nursery, resist the urge to scrub it immediately. Dry scrubbing releases spores into the air, which is the opposite of what you want in a baby’s room.
Step 1: move the cot. Before doing anything else, move the cot to a different room. If the mould is only on one wall, moving the cot to the opposite side of the room may be sufficient as a short-term measure, but a different room is better.
Step 2: open windows and ventilate the room. Air the room out before you start any investigation or cleaning. If it is a warm day, open windows on opposite sides of the house to get cross-flow.
Step 3: photograph everything. Wide shots, close-ups, and photos showing the location of the mould relative to windows, walls and external features. This documentation is useful for insurance claims, for a building inspector, and if you are a tenant, for your landlord request. Our tenant photo evidence guide covers exactly how to do this.
Step 4: look for the moisture source before you clean. If you clean without fixing the source, the mould returns within weeks.
Where mould tends to appear in Illawarra nurseries
Nursery mould in Illawarra homes follows predictable patterns based on building type:
South-facing bedrooms in double-brick homes (common in Corrimal, Fairy Meadow and Towradgi) stay cold in winter. Warm indoor air hits the cold brick and condenses. Mould appears on the top corners of the exterior wall and behind furniture placed against the outside wall.
Newer well-sealed estates (Shell Cove, Albion Park Rail, Calderwood) have the opposite problem: the building is airtight, so moisture from cooking, bathing and breathing has nowhere to go. Without adequate mechanical ventilation, humidity builds until it condenses on the coldest surfaces.
Weatherboard homes in coastal villages (Thirroul, Austinmer, Coledale) often have limited subfloor ventilation, which lets ground moisture rise through the floor structure. A musty smell at floor level in a ground-floor nursery is a sign of this.
Our winter condensation mould guide explains why winter is often worse than summer in many Illawarra homes, and what you can do about it.
The mould also commonly appears:
- On the ceiling directly below a bathroom above
- Around window frames where seals have perished
- Behind the wardrobe if it is against an outside wall (see our mould behind wardrobe guide)
- On the wall behind the cot if it sits against an exterior wall
When to relocate the cot temporarily
The safe rule is: if there is active mould visible in the baby’s sleeping area, move the cot while you investigate and treat. This is especially true if:
- The mould patch is larger than roughly an A4 sheet
- There is a musty smell in the room that persists even with windows open
- The mould has recurred in the same spot after previous cleaning
If someone in the household has respiratory concerns related to indoor mould and children, our mould and asthma guide covers the trigger mechanisms. If a musty smell is making anyone feel unwell, our musty smell, headaches and fatigue guide is worth reading before you decide on next steps.
The cot can return once the mould has been properly treated, the moisture source fixed, and the room has been aired for at least 48 hours.
What DIY is reasonable and what isn’t
For small patches of surface mould (on painted surfaces, window frames or sealant), a solution of warm water and a small amount of detergent, applied with a cloth and rinsed off, is a reasonable first treatment for an adult in a well-ventilated room. Wear gloves and a P2 mask. Do not use the baby’s room as a workspace.
Anti-mould sprays containing fungicide are available at hardware stores, but follow the label carefully and ensure the room is thoroughly ventilated before a baby sleeps in it again. Our summer humidity prevention guide has more on the ventilation habits that prevent recurrence.
What is not appropriate for DIY:
- Mould covering more than about half a square metre
- Mould that has penetrated into plasterboard or timber (not just surface staining)
- Any situation where you cannot identify the moisture source
- Mould that has returned to the same spot more than once
For bathroom-related mould that is appearing on a ceiling shared with a bathroom, our bathroom ceiling mould removal service covers what a proper job looks like.
When to bring in a professional
Call a professional mould inspector when:
- The mould patch is larger than a sheet of A4 paper, especially in a baby’s room
- There is mould in multiple spots or in more than one room
- You cannot identify the moisture source
- Mould returned within a few weeks after cleaning
- There is a persistent musty smell without obvious visible mould
Our mould inspection and testing service uses moisture meters and, where appropriate, thermal imaging to locate hidden moisture that feeds recurring mould growth, and to identify the extent of the problem before any remediation work begins.
If you are a tenant and your landlord is not responding, our tenant photo evidence guide covers how to document the problem formally and what steps the legislation supports.
To discuss your situation and get a no-pressure assessment, contact us here.
FAQs
Is mould in a baby’s room dangerous?
Health questions belong with a GP or paediatrician. From a building perspective, mould in a living or sleeping space raises the airborne spore load, and young children are listed by NSW Health as a group with higher sensitivity. Moving the cot away from visible mould while you investigate is the sensible building-side step.
How do I stop mould coming back in the nursery?
Mould returns when the moisture source is not addressed. The most common sources in nurseries are cold walls with condensation, poor ventilation, and slow water ingress through windows or roofs. Fixing the cause, then maintaining adequate ventilation and keeping indoor humidity below about 60 per cent, is the long-term approach.
My landlord won’t fix the mould in my baby’s room. What can I do?
Start by putting the request in writing and documenting the mould with photographs and a log. NSW Fair Trading provides a process for tenants when landlords do not respond to repair requests. Our tenant documentation guide covers exactly what to record and how to escalate.
Can a small amount of mould in the corner of the room be ignored?
A small area of surface mould on a painted wall is a lower concern than deep mould on porous surfaces, but “ignore it” is not the right approach in a baby’s room. Treat the patch properly, fix the ventilation or moisture source that caused it, and monitor for recurrence. If it returns, there is likely a hidden cause.
Should I throw away soft toys and bedding that were in a mouldy room?
Soft toys and bedding that have visible mould on them, or a musty smell, should be washed on a hot cycle if the label permits or discarded if not. Items that were in a room with surface mould but show no signs themselves can generally be aired and assessed. For guidance on mould on soft furnishings more broadly, our mould allergy symptoms and sensitivity guide has useful context.
Related reading
- Black mould guide for homeowners
- Mould allergy symptoms and facts
- Mould behind wardrobes and furniture
- Mould and asthma in Illawarra homes
- Musty smell, headaches and fatigue at home
- Summer humidity mould prevention
- Winter condensation mould guide
- Tenant photo evidence guide NSW
- Mould inspection and testing service
- Bathroom ceiling mould removal service