How to add shade to a pergola

If the complaint is that the pergola does not actually shade anything, this is the fabric that fixes it — and the density is the reason.

Up to 90% UV block, in a knitted HDPE tape and monofilament construction, with air flowing through the knit. Ninety per cent is what turns dappled light into usable shade. The garden-grade fabrics at 30% and 50% will not do it, and the most common mistake here is buying the cloth that was sold to shade vegetables.

Breathable matters more over a pergola than anywhere else. A pergola is open at the sides, so hot air under a breathable fabric rises through it and keeps moving. Under a solid tarp it has nowhere to go, and you get a hot still box with a shadow in it — which is why the fabric people most often reach for is the worst choice.

A 15-year fabric warranty against cracks, splits and tears due to UV degradation, in 6 x 15 ft, 6 x 50 ft, 6 x 100 ft and 12 x 50 ft. The 12 ft width is the one to buy if your pergola is 10 to 12 ft across: one piece over the whole span, no seam down the middle.

The only fabric here sold cut to your dimensions, which is the right answer if you want to fill the bays between rafters rather than cover the whole roof.

180 GSM knitted polyethylene, 75% block rate, up to 95% UV stabilized, cut from 6–24 ft wide by 1–300 ft long. Cut to size means you can order the exact bay width, or a single piece wider than any stock panel — 24 ft covers a pergola nothing else here will cover in one piece.

It publishes a GSM figure, which almost no shade cloth does. That lets you compare the cloth weight against the shade sails on this site rather than guessing — GSM and shade percentage explained covers how weight and shade percentage relate.

The trade is the edge: a cut edge with no taping. Grommets, edge tape and fixings are all extra, and an untaped knit will run if you tension it hard. On a pergola that is manageable because you are often fixing to timber with battens rather than tensioning hard — but budget the hemming as part of the job. Three-year limited warranty.

A finished sail rigged above the rafters is the tidiest solution of all, and the one that leaves the pergola looking deliberate rather than patched.

190 GSM virgin HDPE, 95% UV block, breathable, reinforced stitched seams, stainless D-rings at every corner, in fourteen sizes from 8 x 10 ft to 16 x 20 ft. Being able to match a sail to the pergola's plan dimensions is the practical advantage over cloth you have to cut and hem.

Tensioning it above the rafters rather than between them has two real benefits. It leaves an air gap, so hot air moves out sideways between fabric and timber instead of sitting against it. And it lets you build in a proper fall, so rain runs off one edge rather than pooling in the middle of a bay.

Hardware is sold separately, which is correct here. You want to fix to the frame's beams rather than its rafters, and choose the fittings to suit. Use stainless, and if there is a pool nearby use 316. Three years of warranty.

The middle density, and often the right one on a pergola specifically — because a pergola is usually sited where some light coming through is the point.

Up to 70% UV block, breathable, knitted HDPE, in the same family as the 90% fabric. Seventy per cent removes the glare and most of the heat while keeping the space bright. Over a dining table under a pergola that is frequently a better result than full shade.

Sizes 6 x 15 ft, 6 x 50 ft, 6 x 100 ft and 12 x 50 ft — the same spread as the 90%, so choosing the lighter density costs you nothing in sizing options.

No warranty is published for this line, where the 90% carries 15 years. That is the one mark against it and the reason it ranks below the denser fabric rather than above it, since the two are otherwise the same material doing the same job at different densities.