Waterproof Tarpaulin

Waterproof tarpaulins and shade sails for the garden and the yard

A waterproof tarpaulin puts a roof over something that has none. The range covers heavy duty PVC and coated Oxford polyester covers alongside triangular and square shade sails in plain colours, in sizes up to eight metres across. The two overlap: a sail is a tensioned sheet that also throws shade, a tarpaulin a loose cover pulled over a load. Both live or die by their edges rather than their middle.

What separates PVC from coated polyester?

PVC is a solid plastic sheet, usually with a woven scrim inside it for strength. It is heavy, stiff in cold weather, impervious to water, and the material to choose for a cover left out all winter. Coated Oxford polyester is a woven fabric with a waterproof layer on one face. It is lighter, folds small and drapes over an awkward shape, but the coating does the sealing and it wears where the fabric is repeatedly creased. Weight is the honest guide: heavier for a permanent cover, lighter for something that goes up and comes down. Sheets cut light enough to be carried on a walk sit separately in camping tarps.

Why do tarpaulins tear at the eyelets?

Because that is where the whole load concentrates. Wind lifts the sheet, the sheet pulls on a few small holes, and the fabric gives way around the metal. Three habits prevent it. Pitch tight, since a flapping sheet does more damage to itself in one night than a month of rain. Tie to every eyelet rather than the corners alone. And use shock cord at each anchor point to absorb gusts instead of passing them to the hem.

What should be checked on a tarpaulin before ordering?

• Finished size: cut size and finished size differ once the hem is sewn. Measure the area and allow overhang on every side.
• Hem construction: a folded and stitched hem with a rope running inside it carries far more load than a plain welded edge.
• Eyelet spacing: closely set eyelets spread tension. Corners alone concentrate it in four places.
• Colour: a pale sheet passes light and keeps the space beneath usable; a dark one shades more and heats up in sun.

Do shade sails keep rain off?

Only the waterproof ones, and only if they are pitched on a slope. A flat sail pools in the centre, and standing water is heavy enough to stretch the fabric and pull out fixings. Set one corner clearly lower than the others so water runs to a single point. Permeable knitted sails are a different product and are built to filter sun rather than shed rain, so read the description rather than the picture. Anything supported by poles instead of by tension belongs with tents & shelters.

How should one be stored between seasons?

Dry first, always. A sheet folded away damp grows mould on the coating, and on PVC those marks stay. Hose off grit, dry it over a line, then fold loosely rather than into the same sharp lines each year, since coatings crack along a repeated fold. The same discipline applies to the roll-top designs held in waterproof bags, where a coating sealed away wet fails from the inside.