Windbreak choices

[raymondo]

I am erecting a 7 meter windbreak. It is not a fence and in a rural area that faces due south from which we get hefty wind gusts.

I understand windbreaks create less turbulence when some wind is able to pass through rather than all over the top. Hence I am thinking about this design above, using 150mm plinth boards. However, my wife would like it painted, so I'm considering treated pine decking. (Bunnings have a 90 mm x 22 mm board)  which is easier to stain or paint. Consequently, it uses more boards. 

I'm wondering if the design below with space would be just as effective as the above design where wind has to feed through the gaps. I can't find any studies or research which compares these designs.

My other concern re the plinth boards is that they sag and warp over time. 

Grateful for any thoughts.

[EricL]

Hello @raymondo

Thanks for sharing that question about windbreak fencing. If you're using 90 x 22 decking boards, I suggest reducing the distance between posts to counteract the sagging and warping of the boards. A diagonal brace will stabilize the decking boards and help keep their form. The mining sites I know of use Shade Cloth to actually slow down the wind as they use it for dust control. 

Your proposed design actually looks quite sound as it will still let the air pass through but at a much slower rate. The only other design I've seen is a diagonal fence at a 45-degree angle. But these are often used on cattle farms. If I happen to see other designs I'll post them here.

Let me call on our experienced members @diy_hausdesigns and @Adam_W for their recommendations. 

If you have any other questions we can help with, please let us know.

Eric

[Adam_W]

Hi @raymondo, the following were in a garden I visited out on Norfolk Island. It was protecting citrus from prevailing salt-laden winds.
Looks quite good & was very effective. Probably a more cost effective option too.
First is wide then I cropped in to show some detail.

[raymondo]

Thanks Eric..  I had considered shade cloth initially, but I know it has to be extremely well secured to prevent fraying. It's interesting about the mining sites. You would  think sand would transmit through shade cloth quite easily. I think I will stick to boards and try to decide between the two board types

cheers

ray

[raymondo]

Thanks for the pics Adam... It certainly looks good. As I mentioned to Eric, I have concerns about the proper mounting of the cloth to ensure against constant buffetting.  I'll give it some thought, however. 

Thanks

ray

[raymondo]

Hi Adam... Just an update on this matter.

I contacted the suppliers of both brands of shade cloth available through Bunnings. One said that their product had not been tested for wind strength and as such, they could not recommend it for that purpose. They other said it "may" be appropriate if mounted properly, but provided no wind strength ratings of specific mounting design guidelines.

There is a chinese company that manufactures shade cloth for the purpose of wind breaks, but it does not seem to be available in Au. 

I was getting to like the idea, but I think on this occasion, I will stick to timber which I know has a proven track record. 

Cheers

ray

[EricL]

Hi @raymondo

Using timber is perfectly alright and as you mentioned has a proven track record. The other ideas that came to mind were, what if you installed the panels at a 45-degree slope to re-direct the wind? So instead of the wind slamming into a solid fence, it passes through it and is directed elsewhere. 

The other one was how about creating staggered bamboo hedges in combination with the windbreak? The bamboo would serve as cover for the timber windbreak and double as a natural windbreaker.

Please keep us updated with your progress, we look forward to seeing your windbreak installed. 

Eric

[raymondo]

The deflecting panels could be good, but I'm a bit pressed for space in this situation.  I have found lots of good articles that discuss the need for some degree of porosity in the design, which will reduce turbulence on the on other side. It might be appropriate to incorporate bamboo as a second stage. Thanks

Incidentally, I notice that Bunnings use shade cloth extensively around the store nursery departments. But they pull it over chain wire mesh. Are you able to find out any info on how they secure the edges?  It always looks tight with no sagging or billowing. 

[EricL · Accepted solution]

Hi @raymondo

I'll be visiting my local store tomorrow, which will let me do a bit of investigation for you. As soon as I get some answers, I'll post them here as soon as I can.

Eric

[Dave-1]

I get very strong Westerlies where I live, I have a timber windbreak already and that works fine, This one is for a coffee tree that was being hammered by the wind and I had loads of "extra" concrete rubble about. Will try and remember to take another photo in spring to see if it comes back. These Gabion cages I purchased from bunnings 800mm by 400mm by 400mm They really break the wind up even another 400mm above the wall