How to Clean Mould From Canvas Tents

Mould is part of the fungi family. Unlike plants, which obtain energy from the sun, mould derives its energy from breaking down organic material. It produces enzymes that cause substances to rot, and the byproducts feed mould growth. While mould plays an essential role in nature as a recycling system, it can damage canvas tents if left untreated.

Mould spores are present almost everywhere—in the air, on clothes, in plants, and on surfaces. It can grow anywhere temperatures remain above freezing but thrives in humid, dark environments with organic material to break down. Forests, coastal areas, and damp campsites are common high-risk spots.

mould spreads through airborne and waterborne spores, which settle and multiply rapidly. In the right conditions, it can start to grow within 24 hours. Early detection and immediate cleaning are key to protecting your tent.

Most mould species aren’t harmful to people without allergies or respiratory issues, but it’s still recommended to avoid direct contact and not inhale spores. For your tent, mould is far more dangerous—it weakens fibers, stains fabric, and can shorten lifespan dramatically.

No untreated natural fabric is immune to mould. Breathable cotton canvas requires a protective coating to resist moisture and reduce mould growth. However, a heavier coating can reduce ventilation, which may lead to humidity build-up inside the tent.

At CanvasCamp, our waterproof and mould-resistant treatments are designed to strike the perfect balance between comfort and durability. We also offer CanvasCare products for maintenance..

For about 90% of users, removing light mould and stains is straightforward:

1. Spray CanvasCare Stain Remover – Treat both the inside and outside surfaces of your tent.
2. Wait 20 Minutes – Let the product penetrate the canvas.
3. Scrub & Rinse – Gently scrub if necessary, then rinse thoroughly.
4. Re-Waterproof – Once the tent is clean and completely dry, apply CanvasCare Waterproofer to maintain full waterproof protection.

 Tip!    If you did not wash with soap, you can apply the Waterproofer directly to clean, dry canvas.

For deeply embedded mould stains or heavily soiled canvas, manual deep cleaning is required. This process is labor-intensive but can restore tents that are still structurally sound.

Step-by-Step Deep Cleaning

1. Set Up and Pre-Clean – Pitch the tent and remove dirt using a soft brush or broom.
2. Treat with Stain Remover – Apply CanvasCare Stain Remover, repeat if needed, then rinse thoroughly.
3. Disassemble the Tent – Separate the groundsheet from the tent body. Clean it separately. Guy lines can stay attached but must also be UV-treated.
4. Prepare Cleaning Solution – Fill a large tub with lukewarm water and add CanvasCare Cleaner. Adjust the amount based on how dirty your tent is. Stir well.
5. Soak the Tent Fabric – Fully immerse the tent for 4–10 hours, stirring occasionally. Overnight soaking is fine.
6. Drying Prep – Prepare a clean, dry surface for laying the tent out to dry later.
7. Drain & Rinse – Drain the tub, keeping the tent inside. Rinse once to remove dirt.
8. Repeat If Needed – If stains remain, repeat soaking and rinsing.
9. Remove Soap Residue – Fill the tub with clean water, stir with a pole, drain, and repeat until most residue is gone.
10. Reassemble – Spread the canvas on your groundsheet and pitch the tent.
11. Final Rinse – Hose the tent down to remove any remaining soap.
12. Dry Completely – Let the tent dry fully before applying waterproofing.
13. Re-Waterproof – Use a sponge, roller, or sprayer to apply CanvasCare Waterproofer. Press the liquid firmly into the fabric and use enough for full coverage.
14. Final Inspection – Once dry, check waterproofing. If water does not bead up, repeat the treatment.

• A tent fabric that has been washed with soap will require 2 to 4 times as much re-treatment solution to restore its waterproofness compared to a tent fabric that wasn’t washed with soap. Apply the product with a sponge, paint roller, or sprayer (plant sprayer) and press the liquid into the fabric, then allow it to absorb. Use the quantity indicated by the manufacturer for the surface area.
• Always let your tent dry completely before storage to prevent mould from reappearing.

Whether you camp seasonally or year-round, proper mould prevention and removal will extend the life of your canvas tent. Using CanvasCare Stain Remover, Cleaner, and Waterproofer, you can restore your tent’s beauty, protect it from further damage, and ensure it’s always ready for the next adventure.

Explore CanvasCare Tent Cleaning Products →

For additional information on tent maintenance and cleaning, please read even more info on tent maintenance and cleaning here.