Window screen and shade factor question

[Sharpy]

Was thinking about this, this morning. Sitting here sanding a guitar and always have waaaaay to much time to think.

Regular screen porch screening.. what do you think the shade factor of it would be? I did the best I could with measuring off a 1" area and then measuring the individual strings. Approximately 11/32" of total string material if you bunched it up.

The math seems to say this would be about 34% solid and the rest open space. But is it really 34% shade factor??? Just looking at it, it sure doesn't look like it would block that much of the light.

Anyone have any input on this

[peterb]

someone anecdotally told me that window screen is approximately 40% shade. But no proof. I guess you could use a light meter to find out.

peterb

[Sharpy]

If only I had one, lol. Should look into how much they are.

Your 40% that was given to you is really close to the math. So maybe in fact it is.

Any other input would be appreciated.

[Peterthecactusguy]

well, window screening can have a tighter weave and it's supposed to be more "energy efficient" so I think that depending on the type of window screening it might vary. 40% sounds about right but I suck at math

[Saxicola]

This is an interesting discussion as I've been looking for a way to get a small amount of shadecloth (that isn't too thick) without spending an arm and a leg. All I need is to cover a 8'x3' area from roughly early May to early August (weird sun and shade issues at my house). I just couldn't see paying $50 or more to order a roll online. I may just pick up some window screen!

[Peterthecactusguy]

TBH if you use it and need to block more you could double up with it a little bit, like say if someone got some and got a light meter and tested it and it's only 20%.. then X2 would be 40%. I dont know what it is but to me 40% seems about right give or take some...

[cactushobbyman]

This is an interesting discussion as I've been looking for a way to get a small amount of shadecloth (that isn't too thick) without spending an arm and a leg. All I need is to cover a 8'x3' area from roughly early May to early August (weird sun and shade issues at my house). I just couldn't see paying $50 or more to order a roll online. I may just pick up some window screen!

Lowes sells packaged shade cloth about the same size at a fair price.

[Tony]

I grow hundreds of plants under it and have grown and sold hundreds more seedlings that were grown under it so I highly recomend it.
There is a very experienced grower and shower in the local clubs that used to work for UC Riveride that first recomended it to me. He said when he worked there they ran experiments on fiberglass window screen, the same kind thats available at any home improvement center, to see what the shade rating was and they came up with 50%.

[Saxicola]

This is an interesting discussion as I've been looking for a way to get a small amount of shadecloth (that isn't too thick) without spending an arm and a leg. All I need is to cover a 8'x3' area from roughly early May to early August (weird sun and shade issues at my house). I just couldn't see paying $50 or more to order a roll online. I may just pick up some window screen!

Lowes sells packaged shade cloth about the same size at a fair price.

Thanks, but do you know the shade %? Everything I've seen at Home Depot appears to be 70-75% which is way too much.

[Peterthecactusguy]

same here, Saxicola. I was going to have to go to some place in Prescott Valley. I gotta find it again, to see if they got the stuff.. IE shade cloth and plastic.. to see what their prices are.

How much light does one lose using plastic? Any? I am not really too sure.. on that one.

[Tony]

I started off using the shade cloth that the home improvement stores sell with orchids years ago, but had poor growth and little to no blooming with hybrid cattleyas, dendrobiums, etc. So I pulled it all off and started throwing my old, used widow screens that I was replacing at the time up on the roof of the green house and in a year they were all blooming their heads off.

BTW, McMaster-Carr has it in bulk if you need it. I have bought a couple 60" x 25' rolls @ $38.28.
http://www.mcmaster.com/#window-covers/=khvswc" onclick="window.open(this.href);return false;

[Peterthecactusguy]

hmm so the window screens were more effective it seems then the shade cloths?

[Saxicola]

Peter,

I think Tony is comparing screen to the shadecloth you get at Home Depot. You can get plastic shade cloth in any percentage from about 30%-90% shade. Unfortunately the rolls you can usually find at the big box stores (and even most nurseries) is sold with the intention of providing shade for people, such as over your back patio. So what I've seen is usually 70-75% shade. Unless you have a fern and begonia collection it is too shady. I want 40%, but could live with anything in the 30-50% range. When I move and set up my greenhouse and outdoor nursery benches I will need a lot of shadecloth so I'll order it off the internet in the % shade that I want. It is just that for very small amounts like I need now screen makes more sense.

Tony, do you find the screen to be more durable than shadecloth? It seems like it might be. I guess I could ask, if you could get a roll or 40% shadecloth or a roll of screen that gives 40% shade for the same price, which would you prefer?

[Sharpy]

I grow hundreds of plants under it and have grown and sold hundreds more seedlings that were grown under it so I highly recomend it.
There is a very experienced grower and shower in the local clubs that used to work for UC Riveride that first recomended it to me. He said when he worked there they ran experiments on fiberglass window screen, the same kind thats available at any home improvement center, to see what the shade rating was and they came up with 50%.

Hmmz, 50% + 20% from the polycarbonate is going to be to dark for me. Was hoping I would get in the 55% range total. Guess I can just get some 30% shade cloth remanents for the areas I will need it. But the screen will be good when aclimating seedlings from flourescent to sun.

Tony, do you find the screen to be more durable than shadecloth? It seems like it might be.

Not trying to answer Tony's question, as I have little to no experience with shadecloth yet. But from what I understand, if you don't have a "finished" edge on the shadecloth it tends to unravell. At least you don't have to worry about that with the screen, or not as much.

[cactushobbyman]

Lowes sells packaged shade cloth about the same size at a fair price. [/quote]


Thanks, but do you know the shade %? Everything I've seen at Home Depot appears to be 70-75% which is way too much.[/quote]

I cover my greenhouse from April through the end of October. I live in the Central Valley and you know our weather. I find most plants do very well. I do have a few that start to elongate most are my Echinopsis spachiana cuttings. Still, 75% of my collection grows outdoors and this year had a great deal of sunburn, 23 straight days of 100 degree plus.