An impregnation spray alone is not enough for a heavily used tent. Impregnation restores the water-repellent layer, but it does not remove dirt, mould or ingrained stains. If you simply waterproof a heavily used tent, you’ll trap dirt within the fabric and shorten the material’s lifespan. In this article, we answer the most frequently asked questions about waterproofing fabric, cleaning and the correct maintenance routine.
When is impregnation no longer sufficient?
Waterproofing is no longer sufficient if the fabric is visibly dirty, discoloured or affected by mould or green deposits. A waterproofing agent restores the water-repellent coating, but it does not have a cleaning effect. If you impregnate a soiled fabric without first cleaning it thoroughly, you will trap dirt and bacteria within the fibres. The result is a fabric that looks treated on the outside, but continues to deteriorate on the inside.
Signs that impregnation alone is no longer sufficient:
- Green deposits, algae or mould patches on the fabric
- Stubborn stains from mud, grass or soot that won’t come out with water
- A musty or mouldy smell after storage
- Discolouration or dark patches that are not superficial
- Fabric that quickly starts to let moisture through again after the previous waterproofing treatment
In all these cases, cleaning must always be carried out before impregnation. Only then will the protective layer work to its full potential and ensure the material remains protected in the long term.
What is the difference between a waterproofing spray and a heavy-duty cleaner?
A waterproofing spray restores a fabric’s water-repellent properties by applying a protective layer to the fibres. A heavy-duty cleaner is a powerful cleaning agent that penetrates deep into the fabric to remove stubborn stains, mould and ingrained dirt. The two products serve fundamentally different purposes and are not interchangeable.
Think of it this way: the heavy-duty cleaner prepares the fabric, and the waterproofing spray then protects it. A waterproofing spray applied to a dirty fabric is virtually ineffective, as the protective substances do not adhere properly to a layer of dirt or grime. A heavy-duty cleaner without a follow-up treatment leaves the cloth clean but vulnerable, without any water-repellent properties.
For routine maintenance, where the fabric is not heavily soiled but has simply lost its water-repellent properties, a milder shampoo followed by waterproofing is sufficient. In the case of intensive use or after winter storage, a heavy-duty cleaner is the recommended first step.
How can you tell if your tent is actually dirty or has simply lost its water-repellent properties?
You can easily test this by sprinkling water onto the fabric. If the water beads up into small droplets, the water-repellent properties are still intact. If the water is immediately absorbed by the fabric or leaves a wet patch, the material has lost its water-repellent properties. Visible stains, discolouration or a rough texture indicate that the fabric is actually soiled.
A tent can be both dirty and have lost its water-repellent properties, but the distinction between the two determines which step you should take first. Check the fabric in daylight for:
- Green or grey discolouration, indicating the presence of algae or mould
- Dark patches or streaks of mud and organic dirt
- A dull or sticky surface that does not disappear after brushing
Does the fabric look clean but still let water through? If so, simply waterproofing it will suffice. Are there any visible stains or deposits? If so, cleaning is the first step, followed by waterproofing the tent fabric.
What is the correct order for maintaining a heavily used tent?
The correct procedure for maintaining a heavily used tent is: first clean it thoroughly, then waterproof it. Never skip a step, as waterproofing a dirty fabric won’t work, and cleaning without a follow-up treatment leaves the material unprotected. A good step-by-step guide to waterproofing a tent consists of four steps.
- Remove loose dirt: Brush any dry dirt, dust and leaves off the cloth before you start wet cleaning.
- Clean the cloth thoroughly: For light soiling, use a suitable tent shampoo. For stubborn stains, mould or green deposits, use a heavy-duty cleaner that penetrates deep into the fibres.
- Leave the cloth to dry: Make sure the fabric is completely dry before applying the waterproofing treatment. Any moisture in the fabric will prevent the waterproofing treatment from adhering properly.
- Apply the waterproofing agent: Spread the product evenly over the entire fabric. Ensure complete coverage, including along seams and in corners.
If your tent has been used heavily and has not been thoroughly maintained since last season, it is advisable to carry out both cleaning steps before applying the waterproofing treatment to the fabric.
How long does the waterproofing last under intensive use?
With intensive use, a good waterproofing treatment lasts on average one to two seasons, depending on the frequency of use, exposure to sun and rain, and how the fabric is cleaned. Regular washing with harsh detergents significantly accelerates the loss of water repellency. A high-quality waterproofing treatment that penetrates deep into the fibres will last the longest.
Factors affecting the lifespan of impregnation:
- Frequency of use: a tent that is pitched every week will need to be re-treated sooner
- Exposure to UV radiation: sunlight accelerates the breakdown of the protective layer
- Cleaning method: high pressure or harsh detergent removes the waterproofing more quickly
- Storage: storing a tent whilst it is still damp encourages the growth of mould and damages the waterproofing
As a general rule, check at the start of each camping season whether the water-repellent properties are still intact using the water droplet test. If this is not the case, it is time to re-impregnate the canvas or treat the polyester before the season begins.
Which waterproofing treatment works best for canvas, polyester and nylon?
The best waterproofing treatment for canvas, polyester and nylon is one that penetrates deep into the fibres rather than simply forming a surface layer. Canvas absorbs more and requires a stronger waterproofing agent than thinner polyester or nylon. All-purpose products suitable for all three materials offer the greatest convenience, provided they are actually effective on each material.
Waterproofing canvas
Canvas is a thicker, absorbent material that soaks up more impregnating agent. A water-based product that penetrates the fibres well works best. Apply it to a slightly damp cloth for better penetration and, in the case of heavy use, repeat the treatment more frequently than you would with synthetic materials.
Impregnating polyester and nylon
Polyester and nylon are smoother and less absorbent than canvas. They respond well to lighter water-repellent treatments that complement the existing coating. Make sure the product is specifically suitable for synthetic fabrics, as some products are intended solely for natural materials and do not adhere well to polyester or nylon.
How Rokimi helps with waterproofing your tent
Here at Rokimi, we have developed a comprehensive range of products to guide you through the entire maintenance process, from the initial clean to long-lasting protection. Our products are specially tailored to the needs of campers who use their equipment intensively and want it to last a long time.
What we offer for the maintenance of your tent or canvas:
- Hood & Tent Shampoo: for routine maintenance and the removal of light soiling such as green deposits and dust
- Heavy Duty Cleaner: for stubborn stains, mould and ingrained dirt that has penetrated deep into the fibres
- Hood & Tent Protection: the most effective waterproofing treatment of its kind, suitable for canvas, polyester and nylon, for long-lasting water repellency
- All products are ready to use, do not need to be diluted and are suitable for both beginners and experienced campers
Whether you want to treat an awning, a dome tent or a canopy, we have the right product for every step. View our full range product range, find out which applications find out which of our products are suitable, or go straight to the Rokimi website For more information, place your order today.
Frequently Asked Questions
Can I wash my tent in the washing machine before I waterproof it?
Washing a tent in the washing machine is strongly discouraged. The mechanical action and high temperatures will damage the seams, the coating and the fabric itself. Instead, use a suitable tent shampoo or heavy-duty cleaner and clean the fabric by hand or with a soft brush, so that the material remains intact for subsequent treatment with a waterproofing agent.
What happens if I waterproof my tent whilst it’s still a bit damp?
With canvas, a slightly damp cloth can actually improve the penetration of the waterproofing agent, but with polyester and nylon, the fabric must be completely dry. If the fabric is too wet, the moisture dilutes the waterproofing agent and prevents the protective layer from bonding properly to the fibres. The result is an uneven finish that wears off quickly. If in doubt, always let the fabric air-dry completely before you start.
How do I get rid of the mouldy smell from my tent, even if the mould patches have already gone?
A mouldy smell can linger in the fibres, even after visible patches of mould have been removed. Clean the fabric thoroughly once more with a heavy-duty cleaner and then leave the tent to dry in the open air and in the sun for as long as possible, as UV light helps to neutralise any remaining bacteria. Do not pack the tent away until it is completely dry, and store it in a dry, well-ventilated place to prevent mould from returning.
Do I need to treat the seams and zips with waterproofing agent as well?
Yes, seams are often the weakest link in a tent’s water repellency and deserve extra attention when waterproofing. Ensure thorough coverage along all seams and corners, as these are the areas where moisture penetrates most quickly. You don’t need to waterproof zips, but you can treat them periodically with a suitable zip wax or silicone spray to keep them running smoothly and prevent wear and tear.
How should I store my tent after waterproofing it to ensure the treatment lasts as long as possible?
Always store your tent completely dry, loosely rolled up or folded, in a well-ventilated area, away from direct sunlight and damp. Storing it in a sealed plastic bag or a damp cellar encourages mould growth and damages the waterproofing. A cotton or mesh storage bag is ideal because the material allows the tent to breathe, which significantly extends the lifespan of both the fabric and the protective coating.
Can I also use a waterproofing treatment for tents on other outdoor kit, such as rucksacks or awnings?
Many waterproofing products suitable for tent fabric also work well on other outdoor textiles such as awnings, porches, rucksacks and garden cushions, provided the material is similar. Always check the product description to ensure it is suitable for the specific material. Universal products such as Rokimi’s Hood & Tent Protection are versatile and can be used on canvas, polyester and nylon, making them suitable for a range of other applications beyond tent use.
How often should I clean my tent if I use it regularly, even if it looks clean?
Even if a tent looks clean on the surface, there may be invisible organic residues, sweat, sun cream and fine dust trapped in the fibres, which can eventually lead to mould and material degradation. As a general guideline, clean your tent thoroughly at least once a season, and carry out a light clean with tent shampoo after each period of intensive use. At the start and end of each camping season, carry out the water droplet test to determine whether waterproofing is also required.