Do you use your trailer to transport items which need to stay dry? Then you'll need a cover. Canvas trailer covers are water resistant (nothing is waterproof) and, when properly looked after, can last for many years. However, they can be expensive! Fret not - making your own needn't be difficult. Here are a few simple tips for doing so:
Choosing the right canvas:
First of all, make sure the canvas you go for is good and thick. Canvas weight is measured in grams per square metre (gsm or g/m2). Something above 300gsm should do the trick. Marine grade canvas is a good option, but not the only one. Make sure the canvas is advertised as water resistant. And as low shrinkage - that way it won't shrink when exposed to the elements and leave you with a cover which no longer fits your trailer. If the colour of your canvas is important to you, check that the manufacturer guarantees it won't fade (and don't go for red - it always fades). Have a look around locally or on the internet to source yourself some quality canvas.
Making a sheet of canvas material into a cover:
Measure the open area of your trailer top. Make sure and measure to the outside edges of the trailer. You'll almost certainly want the canvas to overlap the edges, but by how much will be personal preference. As an example, if your open area is 1m by 2m and you want a 20cm overlap on all sides, you'll need 1.4m by 2.4m of canvas material.
Once you have the right amount of material you can make a cover. If you have access to a good sewing machine and want the canvas to fit nicely over the edges of your trailer, you'll want to cut and sew some corners into it. To do this cut four squares, one from each corner, out of your fabric. The sides of the squares you cut will be the desired overlap. Using the same example as above - for a 20cm overlap, the squares will have 20cm sides. Next, sew these new edges together, and voila! you have a cover.
If you don't have a sewing machine (or the motivation), sewing corners in isn't entirely necessary, but it will make for a better quality cover.
It's a good idea to fold and sew up the edges of the cover to prevent them from fraying. Only a small amount of fabric need be folded and sewn.
Fastening the cover to the trailer:
You're going to want the cover to fasten tightly to your trailer. There are a couple of options here depending on the trailer. If the trailer has a number of hooks around its sides, great! If not, no big deal. Either way, what you want are some decent sized metal eyelets. These can be sourced easily enough from a local hardware shop or online. Make sure they are big enough for either the hooks (or a good rope or bungee in the no hooks case) to go through them.
You're going to need to cut the canvas to insert the eyelets. If you are very handy with a Stanley blade you might be able to cut them this way, but an easier method will be to get hold of a very sharp, round, biscuit cutter of the correct diameter for the eyelets. This can be twisted through the canvas. Put a block of wood underneath the canvas when cutting so as not to damage whatever is underneath. Insert your eyelets, and shape them out so that they are fastened to the canvas.
If there are hooks on your trailer, position the eyelets so they will fix on to the hooks. If there aren't hooks, space them equally along the bottom edges of the cover, and then use rope or bungee to fix the canvas, as necessary, to the trailer.
Now, whatever you've got in your trailer can stay there safe from the elements!