When DIY Is Appropriate
- Surface mould on less than 1 square metre
- Mould on non-porous surfaces (tiles, glass, metal)
- No known health sensitivities in household
- Visible moisture source you can address
- First-time occurrence in that location
When to Call Professionals
- Size: Mould covers more than 1 square metre
- Location: Inside walls, ducts, or other hidden areas
- Type: Black mould (Stachybotrys) suspected
- Source: Contaminated water (sewage, flooding)
- Health: Anyone has allergies, asthma, or immune issues
- Recurring: Mould returns after DIY cleaning
- HVAC: Mould in air conditioning system
Cost Comparison
DIY: $30-100 for cleaning supplies and protection. Your time. Risk of incomplete removal or spread.
Professional: $300-2,000+ depending on scope. Complete removal, source resolution, and warranty. Peace of mind.
Frequently Asked Questions
What size mould problem can I safely handle myself?
Generally, DIY is appropriate for areas less than 1 square metre of surface mould on non-porous surfaces. This includes bathroom tiles, glass, and smooth painted walls. For larger areas, porous materials, hidden mould, or if you have health sensitivities, call professionals.
What safety equipment do I need for DIY mould removal?
At minimum: N95 respirator mask (not a cloth mask), rubber gloves, eye protection, and old clothes you can wash immediately after. For larger areas, add: full face mask, protective suit, and ensure good ventilation with fans pointing out of the space.
When does mould definitely require professional treatment?
Call professionals for: mould larger than 1 sqm, mould in HVAC systems, black mould (Stachybotrys), mould from contaminated water, mould in wall cavities or hidden spaces, recurring mould after DIY attempts, or if anyone in the household has respiratory conditions.
Is professional mould removal worth the cost?
For appropriate situations, yes. Professional treatment addresses root causes, ensures complete removal, prevents spread, and provides warranty. Failed DIY attempts often cost more in the long run due to mould returning or spreading. The peace of mind and health protection add significant value.