Your Test Shows Mould – What Should You Do Next?

Getting a test result that indicates mould can be worrying and confusing.

The good news is that not every case of mould requires expensive building work or professional remediation.

In this guide, we’ll take you through what to do next, step by step, depending on the extent of the mould and whether you are experiencing any symptoms.

First Things First: Don’t Panic

Mould spores are naturally present in all indoor environments in small amounts.

What matters is:

• How much mould is present
• Whether the mould is visible
• Whether it is affecting your indoor environment or wellbeing

A positive mould test is an important indicator that something may need attention – but it does not necessarily mean you have a serious mould problem.

Step 1: Is There a Small Amount of Visible Mould?

If you:

• Can see small areas of mould growth
• Typically find it in corners, around windows or on cold external walls
• And there are no signs of water damage, leaks or significant damp

👉 then in many cases, you may be able to deal with the problem yourself.

Our Recommendation for Small Areas of Mould

Start with a thorough clean of the affected room:

• Remove dust and dirt throughout the room
• Clean hard surfaces thoroughly
• Treat visible mould with a suitable mould-cleaning product, following the manufacturer’s instructions

At the same time, try to improve the indoor environment:

• ✅ Ventilate regularly – ideally by opening windows fully for a short period 2–3 times a day
• ✅ Keep the room consistently heated
• ✅ Move large furniture away from external walls, ideally leaving at least 5–10 cm of space for air circulation

Many minor mould problems are caused or worsened by condensation, cold surfaces and poor air circulation rather than a major defect in the building itself.

Step 2: Does the Problem Improve?

After cleaning and improving ventilation and air circulation, pay attention to whether the room improves.

Look out for:

• Musty or unusual smells
• Irritation of the eyes or airways
• Headaches, tiredness or discomfort when spending time in the room
• A general feeling that the air is stale or unpleasant

If the Problem Improves

👉 The measures you have taken may have been sufficient.

Continue to keep the room well ventilated and monitor the area for any signs of the mould returning.

If the Problem Returns – Without Visible Mould

👉 We recommend testing again.

A follow-up test may help determine:

• Whether there could be hidden mould growth
• Whether mould levels in the room remain elevated
• Whether your cleaning and ventilation measures have improved the situation

Step 3: Does Visible Mould Return?

If:

• The mould returns after cleaning
• The affected area begins to spread
• Or mould reappears quickly after treatment

👉 this can indicate an underlying moisture problem, such as:

• Damp within the building structure
• Cold bridging
• Leaks or water ingress
• Condensation
• Inadequate ventilation

This Is When We Recommend Professional Help

In these situations, consider contacting a local damp, mould or building specialist who can:

• Measure moisture levels
• Investigate the source of the problem
• Identify potential building defects
• Recommend appropriate remedial work

It is important to remember:

Mould is often a symptom of excess moisture – removing the mould without addressing the cause may only provide a temporary solution.

When Should You Seek Help Straight Away?

Consider contacting a professional promptly if:

• Mould covers a large area
• There are visible signs of water damage or significant damp
• The mould repeatedly returns after cleaning
• You are experiencing significant or persistent health symptoms
• The issue affects a rented property, workplace, school, nursery or other shared building

If you are concerned about symptoms or your health, you should seek advice from an appropriate healthcare professional.

In Short: What Should You Do?

1. Small amount of visible mould
   → Thorough cleaning + appropriate mould treatment + improve ventilation and air circulation
2. No visible mould, but you still suspect a problem
   → Consider testing again
3. Mould returns or continues to spread
   → Contact a damp or mould specialist to investigate the underlying cause

Need Help Understanding Your Result?

If you’re unsure about:

• Your mould test result
• What you should do next
• Whether you should test again
• Which approach is appropriate for your situation

…you’re always welcome to contact us.

We’re here to help you understand the problem before you spend money trying to solve it.