How to Remove Mold from Walls Safely — Step-by-Step Guide

Mold on the wall is not just an aesthetic issue. Fungal spores affect air quality and can irritate the respiratory system, especially in children and people with allergies. Here is how to remove mold safely and thoroughly — so it does not come back within a week.

First — Assess the Scale of the Problem

Not every mold outbreak is suitable for DIY removal. If the affected area is larger than roughly half a square metre, or if the mold is behind wallpaper or deep in the plaster, it is better to consult a professional. Large infestations require products and methods that are not available in a regular DIY store.

For smaller patches — a spot in a corner, a mark behind a wardrobe — you can tackle it yourself by following the steps below.

Personal Protective Equipment — Not Optional

Mold spores are invisible and easily inhaled during cleaning. Before you start, prepare the following:

• An FFP2 or FFP3 respirator (a standard surgical mask does not filter mold spores).
• Disposable rubber or latex gloves.
• Safety goggles.
• Long-sleeved clothing that can be washed or discarded after the job.

Ventilate the room before you begin — open a window, but close the door so spores do not spread through the rest of the flat.

What to Use for Removing Mold from Walls

• Ready-made fungicidal products (sodium chlorite- or dichlorophen-based) — available at building supply stores. Apply with a brush, leave for the specified time, wipe off, and allow to dry.
• White vinegar (10%) or hydrogen peroxide (3%) — effective on light staining on tiles and grout. Use caution on gypsum plaster — vinegar can damage the surface.
• Salicylic alcohol — an option for small, localised spots.
• Paint with fungicide — applied over the cleaned and dried surface as a protective final coat.

What not to use: undiluted bleach directly on plaster — it damages the surface and does not penetrate the fungal mycelium. Household cleaning liquid mixtures are not effective against mold.

Step-by-Step Mold Removal

• Step 1: Put on your protective gear and ventilate the room.
• Step 2: Apply the fungicidal product to the affected area and leave it for the time specified on the label (usually 15–30 minutes).
• Step 3: Mechanically remove the mold with a scraper or disposable cloth, seal it in a bag, and dispose of it.
• Step 4: Apply the product a second time, this time leaving it to dry in place.
• Step 5: Once fully dry, prime the surface and paint with a fungicidal paint.
• Step 6: Wash your clothing, and wash your hands and face.

Is That a Permanent Fix?

No — not if the source of moisture has not been addressed. You can clean the mold perfectly, but if condensation continues to form on the wall or there is a hidden leak, it will return within weeks.

If mold keeps coming back or covers a large area, send us a request through the contact form. We will assess the moisture source and propose a lasting solution. We work throughout Warsaw.

When Does the Plaster Need to Come Off?

If mold has penetrated deep into the plaster or masonry, surface treatment will not be enough. In those cases, the plaster needs to be removed down to the structural base, the wall treated with a biocide, and a new plaster layer applied with a hydrophobic additive. The scope and cost of the work is assessed individually after an on-site inspection.