Before using a canvas for the first time,it will need to be preconditioned or 'weathered' in order for it to have itsown natural water repellence.
Set it up and pre-soak the cover with waterusing a garden hose or similar. Avoid using high pressure washers as this mayremove the surface proofing. The fabric needs to completely soak to allow thefabric to swell and relax/shrink back to tighten the weave on drying. Thiswetting/drying process will not only allow the canvas to condition and gain itsfull water proofing properties, but it will also help to close up the stitchingholes.
The process of weathering may take morethan one attempt if you are wetting angled canvases such as canopies, but fromexperience two attempts normally suffices.Never put a damp canvas cover intostorage!
Ensure that the canvas is fully driedbefore packing away. All natural fabrics are susceptible to mildew. For mildewto grow it requires food, heat and moisture. Mildew will result quickly oncanvas if folded away wet or stored in a damp place.
Before storing, wash off any dirt, animaldroppings and vegetation such as leaves with a hose as these can also promotemildew growth and staining on your canvas when stored. Leave to dry naturallybefore storing away.