Green House Plastic

[PD-Riverman]

I am building a small temporary unheated green house (10ftx30ft). I bought at a Auction some time back a 20ft x 100ft roll of heavy gauge plastic feels like 6 mil but there is no markings, no box. This is not clear, I call it cloudy. If you look at the sun through it you can not see the sun. I held it up next to a wall and the light going through it is a little shady but not alot compared to the sun directly shinning on the wall. My question----can I use this or should I buy some clear? I wanted to experiment with the green house this fall/winter/spring and see how I like it--if I do I will build a better house next year and use some UV plastic. Thanks!

[Harry Chickpea]

20 x 100 could be either builder plastic or greenhouse plastic. The difference is the amount of UV protection. If it is builder plastic, it'll last about a year. If it is greenhouse plastic, about three years +- If you use lath strips to hold it on the frame, replacement can be pretty straightforward. A PITA, but straightforward.

[PD-Riverman]

The plastic is actually 21ft 6" wide I am guessing at the 100ft length. I do realize that if its builders plastic it want last but around one season which is all I want it to last this time because I am building a temporary green house in the Garden and it will be taken down next spring. My concern was the "cloudy" plastic-------if I use it will I get enough light being it is not clear?? The green house is simple---PVC pipe---hoop design. Thanks

Originally Posted by Harry Chickpea

20 x 100 could be either builder plastic or greenhouse plastic. The difference is the amount of UV protection. If it is builder plastic, it'll last about a year. If it is greenhouse plastic, about three years +- If you use lath strips to hold it on the frame, replacement can be pretty straightforward. A PITA, but straightforward.

[Callieslamb]

Yes, you will get enough light. I bought greenhouse plastic, UV protected and it isn't really clear. I have also used builder's plastic to as low tunnel covers and it has worked just fine.

[MaineFarmMom]

I agree with Callie. Greenhouse poly is opaque.

I wouldn't put it on with lathes. It's worth it to invest in wiggle wire and channels. You'll have yourself time, it's easier to use than lathes and won't cause the holes that nails do when the wind is blowing. If the frame is steel you can use self-tapping screws to attach the channel, bending the channel as you go to fit the frame.

By the time you get it built and the soil prepped you'll be very late for planting for winter harvests. It's still worth trying. What doesn't germinate in the fall probably will starting in mid to late February.

[Windy in Kansas]

[QUOTE=MaineFarmMom;5436484]I agree with Callie. Greenhouse poly is opaque./QUOTE]

Opaque doesn't admit light. I think you mean translucent. Transparent would be clear.

If I were wanting to ensure a crop from a greenhouse I would get true greenhouse poly which has ripstop features. A tear in builders plastic by wind and you'd probably lose any growing crop before you could get it stopped.

I helped reskin about 15 greenhouses in 1986 and all of the poly was translucent.

[sassafras manor]

I operate a 4 1/2 acre wholesale greenhouse here in central Illinois and generally speaking white plastic is used for cold frame or overwintering structures rather than for activly growing crops. The diminshed light levels compared to normal greenhosue poly keep the house on the cooler side since the sun cannot radiate thru and warm the inside but in turn will stretch the plants. Aside from regular greenhouse poly having UV protection on the outside of the sheet, there normally is an anti-transpirant applied to the inside of the sheet to help condensation roll down the inside walls rather than dripping like a rain shower. If you can tell me the manufacture's name I can tell you if it builder or greenhouse poly. Also for what it is worth the list price for wiggle wire track is $9.70 for a 9' section and the wiggle wire itself is $2.75 for a 6' piece. The wiggle wire is very handy if this is going to be a permanent structure but you cannot beat the price of a 50 ct. bundle of lathe for $10 that will hold for 3 years if installed correctly. Several of our quonset houses have not been retrofitted with wiggle wire yet and hold just fine with lathe thru the life of the sheet of plastic. I hope this helps.
Matt

[Raven12]

It was mentioned that the greenhouse plastic will last three years. Is that with the hoop house up all year or taken down at the end of each season?

[sassafras manor]

All greenhouse plastics are rated (gauranteed) to have an expected life anywhere from 18-50 months. A 3 year plastic for example will last 3 years if left on while it may only last 2 years if it taken off and put back on again...too much wear and tear in the up and down process.

[Wanderer]

Originally Posted by sassafras manor

All greenhouse plastics are rated (gauranteed) to have an expected life anywhere from 18-50 months. A 3 year plastic for example will last 3 years if left on while it may only last 2 years if it taken off and put back on again...too much wear and tear in the up and down process.

Unless you happen to live in Texas during the worst heat spell in history. Then a 4 year rated greenhouse plastic will last 10 months. Am now fighting with the manufacturer to get a replacement or refund.

A "cloudy" (not white) plastic will have a light transmission of 80-90 percent, which should do fine for most plants.

[sassafras manor]

For a homeowner yes a white covering will do fine but from a commercial standpoint there is too much shade in a white covering. White coverings are usually rated at 35, 50 or 75% shade whereas some of the better clear poly films only have a light transmission in the 75-77% range. The acrylic glazing has the highest next to glass with a light transmission rating of 88-91% and polycarbonate glazing tend to run in the 80-82% range.

[Copperhead]

When I built a hoop greenhouse for my strawberries -- yes I like strawberries that much! -- I used 20 ft, 1/2" rebar and 11 mil plastic from

http://www.northerngreenhouse.com/pr...olys/clear.htm

Next year will be our 3rd spring and it is still going strong despite 3 feet of wet snow annually. I even partitioned off one of the beds and raised chickens and rabbits over the winter. It's not perfectly clear, but it does reflect and refract light inside the greenhouse. There are no shadows inside and the strawberries have done well!





Our strawberries did so well last winter, and so poorly when we replanted this spring (too hot), we replanted them about 2 weeks ago. The Swiss Chard in the middle is all volunteer!

[PD-Riverman]

What I am trying to do is extend my growing season, protecting plants that are already growing as well as growing some "greens" etc. I have never had a fall garden and my late tomatoes, peppers look so good I wanted them to last as long as they can(with in reason) so I figured I would put a unheated green house over them. This green house will have to come down in early spring to get it out the garden. I thought if I liked "messing" with "it" I would build a bigger, better green house next year in a permanant spot with better plastic etc. I just did not want to use this plastic if it was going to cause the plants to not get enough light. It looks just like Copperheads picture. Another thing is I like to stay busy doing things so I figured this would take a couple days playing around with it to get it built, then I can spend some time planting greens etc in the empty spaces, I might drag out the old wood heater with the copper coil and heat water to give the green house some heat---put some solar panels to run some light, fans etc---as I said I like to stay busy so this project might keep me busy all winter--LOL. Thanks

Originally Posted by MaineFarmMom

I agree with Callie. Greenhouse poly is opaque.

I wouldn't put it on with lathes. It's worth it to invest in wiggle wire and channels. You'll have yourself time, it's easier to use than lathes and won't cause the holes that nails do when the wind is blowing. If the frame is steel you can use self-tapping screws to attach the channel, bending the channel as you go to fit the frame.

By the time you get it built and the soil prepped you'll be very late for planting for winter harvests. It's still worth trying. What doesn't germinate in the fall probably will starting in mid to late February.

[Homesteader73]

Good looking greenhouse copperhead. My wife and I built a gambrel framed greenhouse about the year 2000. I used a 6 mil plastic from a greenhouse supply, can't remember which one now. But the plastic lasted until 2007! It survived high winds and Ice.

[taylorlambert]

PD could you post a pic of your heater? Im wanting to build one for my greenhouses on the same principle. I had an older friend that had a small attached greenhouse on his barn. he had 1by4s made into long boxes that had bottoms in them. Starter trays fit into them and he had a water hose from an electric water heater that he had a circulator pump running. He had the hoses coiled up in the bottoms of the boxes. He got 10 weeks ahead of his unheated gh. He said if one plant in the green house one must heat the whole house if its air heated. If the ground is heated you can heat individual plants. When he passed way his lousy kids tore down the green houses and scrapped the heaters he made.




Not to hijack the thread I use growers supply for my covering on the 13 by 20. Its supper stout stuff to. I think it cost 150 for the material and its almost 3 years old now.

[YuccaFlatsRanch]

Before any of you start buying and building Greenhouses you should rad the book called "The Four Season Harvest". The thing most people don't realize with greenhouses, especially where it gets cold (and I live just outside San Antonio, TX - it doesn't get cold) is how much extra heating is required to keep a greenhouse growing. Read the book!!!

[MaineFarmMom]

Originally Posted by YuccaFlatsRanch

Before any of you start buying and building Greenhouses you should rad the book called "The Four Season Harvest". The thing most people don't realize with greenhouses, especially where it gets cold (and I live just outside San Antonio, TX - it doesn't get cold) is how much extra heating is required to keep a greenhouse growing. Read the book!!!

Four Season Harvest doesn't recommend keeping a heated greenhouse in cold areas. Greenhouses aren't used often in winter in these areas. High tunnels/hoop houses are used. They aren't heated, which is the difference between a greenhouse and high tunnel. If you know what to grow, how to water, when to plant, etc. there's no need for heat. I have 2,500 sq ft and never a bit of heat other than the sun.