Brush and Vacuum

• Since most canvas tents are treated with special chemicals to make them waterproof, stain-resistant and mildew-resistant, it's not necessary or even advisable to wash them. Doing so can ruin or deteriorate the water- and mildewproof finish. If your canvas tent is simply dusty and dirty from regular use, the best way to clean it is to use a brush or broom and vacuum. Shake the tent out and brush or sweep away as much dust and dirt as you can. Then use a handheld vacuum, vacuum attachment or shop vac to remove the remaining dirt.
  
  

Mild Cleaner and Rinse

• If the tent is stained, deeply soiled or showing signs of mildew, a deeper cleaning is required. Choose a mild cleaner that doesn't contain detergent, such as Woolite, and mix it with water in the amount recommended on the bottle. The detergent will break down any special coatings your canvas tent might have. Wash your tent in the mixture and then rinse thoroughly. A bathtub or plastic wading pool can work well as a wash tub for your tent. After rinsing thoroughly, hose the tent down one last time to make sure all the cleaner is removed. Let the tent dry thoroughly before packing it away.
  
  

Vinegar and Water

• If your tent has mildew or mold, something stronger than a mild cleaner may be required. Mix vinegar half and half with water and spray it on the tent or soak the tent in the mixture, depending on the size of the area to be cleaned. Then scrub away the mildew with a brush and rinse the tent thoroughly. Allow the tent to dry completely before putting it away or the mildew could return due to the moisture remaining in the canvas. You can clean your canvas tent with bleach using this same method, but you will need to apply a new waterproof coating since the bleach will break down any treatments that were previously applied to the canvas.