Canvas tarps are often used to cover stationary objects such as deck furniture, boats, cars and a plethora of other outdoor items, providing a flame-retardant and breathable seal over them. Oftentimes, these tarps get mildewed and dirty due to their constant exposure to both the ground and the elements. Cleaning a canvas tarp requires some extra work since you can't put it in a laundry machine and dryer. The stitching can be delicate, which makes hand-washing a priority, but the tarp is often large, eliminating the possibility of washing it in a sink. However, you can clean your tarp relatively painlessly using a couple of different methods.
Spread your canvas tarp outside. Mix dish-washing soap with warm water in a bucket.
Dunk a sponge or dishcloth into the soapy water. Remove the soaked cloth and then scrub the outside of the tarp.
Rinse the tarp with water and then hang it on a clothesline. If the clothesline is a double line and the tarp is very large, extend it across both lines. Scrub the other side of the tarp and then rinse. Allow the tarp to hang dry. Do not put the tarp into a dryer.
Place the tarp into a large sink or in a tub. Run water over it until the material is submerged.
Add soap to the water and mix the water around. Rub the tarp with a cloth or a sponge on both sides.
Drain the sink or tub and then squeeze the excess water from the tarp. Hang the tarp to dry. Do not put the tarp into a dryer.