Can rats, squirrels, chipmunks and mice chew through the 4mm poly sheets? We are overrun with the varmints down here.

Most poly is 6mm. It is surprisingly strong. A pressure washer will not damage it. Not that you have to worry about snow, but a single layer of 6mm was enough to collapse my high tunnel from snow, without tearing the plastic first. It pulled five 4x4 posts set in concrete, at each end, about two feet at the top. The force required was enormous. My other greenhouse held, by my guess, over 2,000 pounds of snow and ice on the plastic with no damage.

If you use double-layer poly, you'll need an inflation blower. Use outside air to inflate. Also, if you have roll-up sides, use a single layer for that part, not a double, because it can't be inflated. Without inflation, the layers of plastic rub together and turn cloudy very quickly.

The newer plastic has an "infrared block" quality to it. It is opaque, not clear. It is a lot better about not getting too hot in full sun. Clear plastic will make a solar cooker in the late spring and summer.

[QUOTE=ScottinAtlanta;590653]Can rats, squirrels, chipmunks and mice chew through the 4mm poly sheets? We are overrun with the varmints down here.[/QUOTE]


Scott I have had them chew through thick plastic tots to get to bird food.

That is what these critters do chew chew chew.

Worth

Folks, I have decided to build a greenhouse using old house windows that people are throwing in dumpsters around here. Thanks for all your suggestions - I looked at them all, considered carefully, and decided that the best thing that will work for me is a glass greenhouse, customized to my lot, and built of free stuff that would otherwise go into the landfill. I will post a photo here when the 14 by 25 foot greenhouse is done.

Sounds good, can't wait to see it!

I have seen some bad a$$ green houses made from throw away windows.
Don't forget the sides (North) away from the angel of the sun dont need glass.

Those old windows were made to be mounted vertically. They are great for that purpose in your greenhouse. However, they were never meant to be a roof. You will have to overcome the issue of water pooling on them, and you won't want to be underneath them the first time a decent-sized hail stone hits, or it will maim you for life.

Hail isn't an issue here in Atlanta (well, except once in a decade or so), but tree limbs are the big issue. I am thinking of putting crosswise 2x2s across the roof to try to reduce the impact of falling limbs, but I am sure I will need to replace panes now and then.

Here is my hightunnel build
[url]http://www.tomatoville.com/showthread.php?t=39087[/url]

Get a $75 jig and bend your own hoops, you'll save thousands.
Look up HOA and city bldg permit info. My thread has tons of info about that.

Def. go for double poly. You dont need an inflation blower. I used spacer blocks between the layers, they work great.

Im finishing a 100 ft run of conduit...electric and 1/2" gas line. The cold spring almost got my toms. That wont happen now. So, think about heat now, you'll likely want to add it later.

I'm trying to think how to keep water from pooling along the downhill edges of the window panes. Maybe some clear silicone on those places would do the trick. If water sits anywhere, it will rot the wood.

I would just pull the glass and make my own frames it it was wood..
What a frigging pain.:lol:

Worth

[QUOTE=Cole_Robbie;591248]I'm trying to think how to keep water from pooling along the downhill edges of the window panes. Maybe some clear silicone on those places would do the trick. If water sits anywhere, it will rot the wood.[/QUOTE]

Great idea.

What about using those rigid poly type sheets thingies for the roof area only? Less likely to get chewed through there, and would let rain run off, plus if they broke, not as dangerous as glass.

Just a thought- I know nothing about building anything.

In my opinion: By the time you finish "modding" used windows so they work for your structure you could have finished the GH if new GH specific products were used.

The last thing I'd want to do is try and invent something only to have it work "so so" after all that time and effort.

Use products for how they were intended, my opinion only.

[QUOTE=imp;591295]What about using those rigid poly type sheets thingies for the roof area only? Less likely to get chewed through there, and would let rain run off, plus if they broke, not as dangerous as glass.

Just a thought- I know nothing about building anything.[/QUOTE]

I wasn't very clear, sorry.

I meant that using the poly whatevers, and allowing for a slight over hang - like a house roof has- and the windows for the wall areas.

I think with the poly sheets you could also set up rain guttering to catch water and use it.

I'm babbling now.