September 23, 2012 by: Ben Heimsath

In our hot, humid climate, the best way to beat the heat is to get some shade.  For residential architecture, porches, awnings, and trellises are the classic shading devices.  There also are tents, and canopies that use fabric materials for shading.  A relatively new product, the sun shade, or sun sail, offers good architectural solutions that are permanent, inexpensive and very flexible.

Sun shade underneath resized 600For our region, traditional fabric-covered structures haven't been very popular in the past.  Tents or canopies have been used for temporary applications, but thanks to high winds and sudden storms, they aren't permanent solutions.  Canvass awnings or porch covers may work in other areas, but the fabrics have tended to fade or become threadbare when subject to the beat down glare of the Texas sun.  I had a serious sun problem at my own house recently, so it was time for me to try out the new materials.

Last summer, the sun and heat were unprecedented. At the house, our side porch was exposed to relentless sun.  Our kitchen garden soon became a graveyard of potted plants scorched by a relentless sun.

This year, in the early spring, we replaced the plants and enjoyed lush growth on the porch all spring long.  I used the herbs regularly in my cooking and my wife's new desk had a great view of the brightly colored leaves and flowers.  As summer approached, we were determined to keep the porch garden growing.  We needed some shade.

There are a number of solar shade or sun sails options.  The simplest are triangular or rectalinear-shaped with anchors at the corners.  Unlike the traditional canvass porch or awning covers, these fabrics are woven loosely to allow some light transmission.  Though they tend to repel water, they are not water-tight.  We found several options that would work for our porch cover and began comparing prices on-line.

Several local companies have made fabric structures very accessible.  They can custom-make interesting shapes for any number of applications.  But for our porch shade, nothing could beat the prices we found for a triangle shade that looked like it would work perfectly.  Most were in the $100 - $200 range, but we luckily found a sale and ordered a triangle sun shade for $50.00.

With some pre-planning, we located good places to anchor two of the corners on exterior walls.  The outside point of the triangle would need a vertical post or pillar somewhere near the porch stair.  Though we could have placed a tall post, we opted instead to bolt a metal bar onto an existing post.

residential-sun-shade-exteriorNow, the summer is nearly over and the sun shade has proven to be amazingly effective.  The plants are still green -- I've enjoyed my herbs all summer long.  The flowering plants are still thriving, though we've added several like the bougainvilla that don't mind the heat.  

The biggest surprise, however came the moment we set up the sun shade.  The triangle not only shaded the porch, but also blocked the sun from the wall with western exposure.  Within minutes, the room inside felt cooler.  The difference has been so significant, there have been days when the outside sun beat down all day, and we barely needed the air-conditioning.  I'm rather certain we saved enough in electrical bills to more than compensate for the total installation cost of less than $100.  

I can recommend a few pointers from what we learned in the process:

Plan the anchor points carefully.  

We noted several warnings about anchoring the sun sail to the sides of houses.  There is significant pull on the corners, so you can't just nail or screw into the siding.  We located two of three anchor points so that lag screws could go deep into the framing.  For the remaining corner, we would have needed a fairly large post set deep in the ground.  We already had some solid posts on our stair, so instead, we anchored the metal bar to one of the existing posts.

Consider how to maximize the shade.

For our porch, the worst sun comes late in the day.  At that hour, the sun angle is very low, so we angled the sun sail to block as much sun as possible.  A commercial establishment in our neighborhood installed a larger version of the same sun sail this summer, but they didn't adjust the angle to block the late afternoon sun.  As a result, the structure provides very little shade when it is most needed.

Be ready to make adjustments.

Though the shade sail installs quickly, it is a tensile structure.  The cables need to be moved around to get the sail to stay fully stretched.  Fortunately, I had a patient helper and after several rounds of adjustments, we got the right balance of tension on each point.  I kept turnbuckles on all the points in case there needed to be further adjustments, but so far the tension has remained constant.

Have a quick release.

When the weather report called for thunderstorms with gusts up to 40 or 50 mph, I was glad we left a hook on at least one of the attachments. The sail looks pretty strong, and the anchors are solid, but hey, it’s a sail.  I didn't want my structure taking off in the high winds. I loosened the turnbuckle from the outside anchor and rolled the sail up on the one side between the two walls to ride out the storm.  


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Austin/ Residential Design & Construction/ Architects and Construction/ Sustainable Deisgn