Green House covering

[snappybob]

I just finished framing my greenhouse for starting my tomato seedlings. It will be a temporary greenhouse that I just use for a couple of months in the winter. I'm trying to decide what I want to cover it with. The greenhouse is a quansit hut type of shape so plastic sheeting that comes in rolls is what I need. If money were no object I would go out and buy some greenhouse covering material for about $200. The greenhouse is only 8' x 8'. Will I get terrible results if I just use moreless clear plastic drop cloth and replace it every year or do I need to bite the bullet and get plastic specially made for green houses? Here is a pic.

[alamo5000]

Originally Posted by snappybob

I just finished framing my greenhouse for starting my tomato seedlings. It will be a temporary greenhouse that I just use for a couple of months in the winter. I'm trying to decide what I want to cover it with. The greenhouse is a quansit hut type of shape so plastic sheeting that comes in rolls is what I need. If money were no object I would go out and buy some greenhouse covering material for about $200. The greenhouse is only 8' x 8'. Will I get terrible results if I just use moreless clear plastic drop cloth and replace it every year or do I need to bite the bullet and get plastic specially made for green houses? Here is a pic.

I use a clear tarp for my covering and it works great. For the size you are talking about I just looked on the website where I bought mine and ther price for a 8X10 clear plastic tarp was $11.20 plus shipping.

Maybe total $20 and you can use it for years if thats the size you want. A 10X20 foot one is 28 bucks.

In my experience you can use the drop cloth plastic rolls from Home Depot, but they are prone to nicks and scrapes.

[Worth1]

I have some 6 or 8 mill vapor barrier that would work fine.

It is clear and strong enough to last a winter at least.

I got it at home Depot but I cant remember the price.

Going there today to get some stuff to fix a ladies door and will look.

I have to ad that if it were to be permanint I would go with tempered glass panels.
Along with auto heat, vents and fans.
I had the opportunity to have this but I opted for a new driveway.

Worth

[snappybob]

Originally Posted by alamo5000

I use a clear tarp for my covering and it works great. For the size you are talking about I just looked on the website where I bought mine and ther price for a 8X10 clear plastic tarp was $11.20 plus shipping.

Maybe total $20 and you can use it for years if thats the size you want. A 10X20 foot one is 28 bucks.

In my experience you can use the drop cloth plastic rolls from Home Depot, but they are prone to nicks and scrapes.

Two 8' x 10' tarps would probably work pretty good to go across the top. Of course they are sold out of those.

I called my local nursery and they have a 12 foot roll for 96 cents a linear foot. I'll check HD also.

[alamo5000]

One thing you probably want to do is make sure the tarp is ONE PIECE.

If not, wait until a windy day and you can find out why.

[les matzek]

hi bob,
i have bought clear plastic from hd (6&8 mill) i was luckey to get a full season out of it sometimes i had
to replace before the season was over for the last 4
years i had to replace in once (6 mill) i bought it
from mega greenhouse supply.
my greenhouse is 12 foot by 16 foot i payed $ 68.00
for a 12 foot by 50 foot that was enought for all the
walls i put 23% white shade cloth on the roof i think
that you would far ahead by useing the 6 mill green-
house film,regards.

les

[Worth1]

Originally Posted by les matzek

hi bob,
i have bought clear plastic from hd (6&8 mill) i was luckey to get a full season out of it sometimes i had
to replace before the season was over for the last 4
years i had to replace in once (6 mill) i bought it
from mega greenhouse supply.
my greenhouse is 12 foot by 16 foot i payed $ 68.00
for a 12 foot by 50 foot that was enought for all the
walls i put 23% white shade cloth on the roof i think
that you would far ahead by useing the 6 mill green-
house film,regards.

les

Les the only reason I mentioned the vapor barrier is Snappy said two things.
1, temporary.
2, two months,

Those 2 months more then likely it would be January and February.

You are right the stuff will break down fast if left up all year long because there is no UV protection.

Snappy what ever you do you will have to vent the top or even on our cool sunny days your plants will roast.
I put a thermometer in a cold frame I built a few years ago and at 50 degrees it got to over 100 in the frame with the sun out.
something you could close at night would work nicely.

Some brooder/heat lights should keep it warm enough at night.

By the way the setup looks nice.

Worth

[les matzek]

hi bob,
as worth said above on a sunny day it can reach between 100 to 105 degrees even if you put vents
in the roof as my greenhouse did before i put shade
cloth on the roof.

now i have the plastic on the sides with shade clips so i
can raise the plastic up as heigh as needed to keep the
temp. as cool as possiable,good luck and regards. les

[snappybob]

I was thinking of leaving the ends open except on cold nights when I need to heat it. Do you think it would get too hot even with the ends open?

[David Marek]

For that size you should be fine if the ends are open. For reference, I worked at a nursery that had a lot of 15 x 80 ft quonsets- on a sunny 50 degree day they had good growing conditions for tomatoes with only the doors on the ends open.

Before covering we wrapped any sharp edges with duct tape to avoid holes being poked in the plastic. If you can find greenhouse plastic it would be a plus. If you opt for the vapor barrier, better have a spare just in case.

[les matzek]

hi bob,
if you left the ends open in the winter the inside temp
would be just about as cold as the outside air.
this is the reason i made my side plastic so i could
raise them just enought to keep the inside temp at
68 to 70 degrees,i go over the shade cloth with 6
mill greenhouse plastic in dec.,jan. feb. that i take
the plastic of the roof,regards and good luck.

les

[alamo5000]

I leave the end of mine open... just one end...and it does not over heat.

I will also recommend getting a remote thermometer so you can keep tabs on it. I spend 47 bucks and got one and its been great. It even keeps a temperature history.

I also say on the whole covering thing... make sure that whatever you use is SECURELY attached to your greenhouse. One good windy day and you got one big old kite.

My greenhouse had the roof torn off of it once because it wasn't secured enough. Just make sure there are no edges for the wind to get up underneath... especially if you plan to use some of the rolls of plastic.

[snappybob]

Wow, I'm getting a lot of great tips here. It hadn't accured to me to tape up the sharp edges on the wire panels. As of today I have seedlings up so I may not be able to get covering by mail. I think tomorrow I will got to the nursery and get the greenhouse covering. I can do that for around $30. I still have some time before the seedlings will have to go in there but I want to start getting some experience with how to manage it before I put plants in there. I have two remote thermometers. I used one to monitor a little miniature 2' x 4' hoop house that I erected a few years ago. I'd like to get one that keeps a history but that may have to wait. I was thinking of securing the plastic to the wire with those spring steel office binder clips. The nursery supposedly has some securing stuff too. I'll see what they have and/or what they recommend. I can't thank you guys enough. You've been really helpful.

[stormymater]

Careful with the clear stuff - it really heats up, even on cold days - we're going with the white 6mm stuff that has good light penetration - less overheating, less mold/mildewy problems with the plants (less chance of roasting them too). There is a clear tape with a waffly texture that my friend uses before he staples the plastic to his frame. It enables him to pull the duct tape width tape like a giant bandaid when he wants to pull the staples & open his hoophouses. Staples come out cleanly w/o tearing covering - he does it for ease, I'll be doing it to extend the life of the covering. He also runs external strapping every 4 feet to minimize flapping of the covering.

[David Marek]

Seems you already mentioned it, but I forgot to mention wiggle wire (officially called aluminum locking channels or wire lock channels). It makes it easy to open a corner or completely remove and reuse the plastic many times.

We put a piece of fabric between the plastic covering and the wiggle wire for the sections that get opened frequently so that the wire does not wear through the plastic.

Enjoy your new greenhouse!