Louvred Pergola

September 1, 2024 7:52 AM

I am thinking about a louvred pergola for the back patio, something like this. Please share with me your experience with these.

This is in Colorado, USA. Do these handle rain, snow, and hail?
Does rain drip through?
Can they handle the weight of snow?
Do they withstand hail?

The area is approximate 18' x 15'

posted by falsedmitri to Home & Garden (11 answers total)

Are you planning to grow vines over it?
posted by zadcat at 7:57 AM on September 1

Response by poster: No vines
posted by falsedmitri at 8:09 AM on September 1

The pergola you linked doesn't provide any shade, nor protect from rain, snow, etc. Unless you put up a covering, or plant something that will grow over, it will be simply a feature to that makes stripes of sun and shade.
If that is not an issue then it can be a nice way of delineating "this is where we sit", or grill, or have plants, separate from the rest of the yard. If it's metal it should have no problems with rain, snow, hail; wood might need treatment. It might need to be secured to a deck or placed on a paved surface to remain stable.

I was confused by the difference between a pergola and a gazebo (and I will walk around chanting those words until I'm senseless, they just get weirder) so I found this description, which helps with searching for products and deciding what you want.
posted by winesong at 2:22 PM on September 1

We built our pergola and absolutely love having one. Ours is pretty sturdy. Actually, it's over-kill, as we used 2"x6" cover boards standing upright. The advice we were given was that using 2"x6"s spaced 4" apart would give the most shade and be sturdy enough to withstand our hard North winds. There's always shade, except at noon. It would probably withstand a hurricane, but realistically, after talking with other 'experts' and seeing what other people have built that has lasted, I think we would have been better off using good quality 2"x2"s spaced 2" apart.

With a clear span of 18'x15' using only 4 uprights, you're going to have to make sure you have a really good support structure/materials, or you'll need to put in 6 uprights. Three on the 18' side (1-9-18) would be plenty. You might be able to have only two running on the 15' side by using uprights placed 1.5' in on both sides and hanging the cover over 1.5' on either side. That may or may not work with your existing deck, or depending on the orientation, you may want to extend the pergola out past the 15' to get more afternoon shade.

Yes, rain gets on the deck. No problem with hail; snow doesn't build up here (Idaho), but we don't have snow for days on end, either. My friend in Montana doesn't have a problem with snow--they toss a rope over the pergola and drag it across to knock snow off if it builds up and they look to be expecting heavy ice storms, but she says she doesn't have do it often.

We wouldn't be able to sit on the deck in the summer without the pergola, and it enables growing a variety of supposedly sun-loving plants that would just give up in the direct desert sun we have here. The only thing I really wish was different is the size--we could have doubled the length of it, and then even extended it out further to where it was over part of the grass. Having that partial pergola shade and hanging a shade cloth on the west side in the afternoon has made life bearable in our backyard in July and August.
posted by BlueHorse at 4:06 PM on September 1

Oh, I forgot to say--My friends with the louvered pergola say they had they known, they wouldn't have bothered to get one that was louvered, as they hardly use the louver function. From what I can tell, the louvers have a tendency to stick as they get older and get dirty, and they should be left upright unless you're actually using them--overnight, etc. (Their deck still gets wet when it rains when they're shut.)
posted by BlueHorse at 4:16 PM on September 1

We built ours with components from Tojagrid. It's open-top, no louvers, but we've thrown wooden strips up there to form a grid which supports a wisteria which is growing fast. The wooden beams came from Home Depot; I think we should've paid more for treated wood, or coated them with something before assembly, because the vertical supports aren't anchored and those beams are starting to twist.

I was confused by the difference between a pergola and a gazebo

Shouldn't be, a gazebo is round and pergolas are rectilinear. The latter are also known as Patio Covers and maybe that term's easier to remember. They can also be attached along one side to your house, which is what I wanted; but if attached (at least in my jurisdiction) permits from the city are required, unlike ours and the one in the OPs picture.
posted by Rash at 5:41 PM on September 1

I generally think of a gazebo as a smaller self-contained structure with an actual roof while a pergola is more like a trellis and rectangular, but with one dimension that's pretty open-ended depending on how it's used - like, if you had a 200' walkway from your garage to your house and put a post-and-beam structure over it, sure, that's a pergola. You can get shade either by having it be a trellis or having vines grow over it. In the case of the linked product, it seems more like they're using "pergola" as a marketing term like it's a fancy architectural thing you might not have heard of before. They're probably not the first to do so.

So, with this linked product, I can't see it being watertight, and it probably doesn't want to be. If the louvers are closed and it's watertight, they have to be designed to carry the water weight of the little pool that will form without deflecting under the weight at all and that seems like an order of magnitude of additional engineering that they don't want to do and you don't want to pay for. If the louvers are open, I think you'd have a hard time building up enough snow to span the gaps and cause a problem, but you'd probably want to check with the manufacturer.
posted by LionIndex at 6:26 PM on September 1

This should work; it’s very similar to a Costco product that is similar (but manual, not motorized) and that model has an internal gutter and drain system that takes care of rainwater. As long as the slats are moved upright before snowfall you should be fine.

…the Costco product is called Mirador (I’m on mobile); check it out to compare. I’d be surprised if the more expensive version didn’t also have a gutter and drain, but the company should be eager to tell you.
posted by aramaic at 8:30 PM on September 1 [1 favorite]

Best answer: I have a large one somewhat like that in Grass Valley, CA. Maybe 20x15 feet? Photo here. It's not louvres though, it's little metal beams that provide about 50% shade on top of a quite robust structure of long structural beams.

It works great in the summer for providing shade. Rain is not an issue, it just drips through. Snow is a problem: it collects on top and the pergola has to be engineered for a snow load just like you would a flat roof. We don't get crazy hail here but it seems reasonably OK, being metal, maybe some of the finish on top is damaged where I can't see it?

The lighting is something we added and it looks great, particularly at night. These are incadescent bulbs but it'd be much easier to do with LED ropes.
posted by Nelson at 10:06 AM on September 2

We've had an arched pergola that we built for close to 10 years now. The boards are closer together than the ones in the picture you provided and it provides decent shade, but no rain protection. We haven't had any problem with snow, but again, it's arched so the snow tends to shed after a point.

We love ours and we put hanging baskets and some solar LEDs on it.
posted by plinth at 6:35 AM on September 3

Response by poster: After reading the responses, I guess a louvered pergola will not provide protection from rain and snow. I might be looking towards something with a retractable roof now.
Thanks!
posted by falsedmitri at 9:08 AM on September 3