Most of the time when I see a home made greenhouse constructed out of old wooden windows they don't use windows for the roof, they use something like corrugated plastic roofing. I think it is because the windows are not designed to handle the stress from rain and snow weighing down on them.

I know it may sound like a hassle but if it was me doing this, I would build the frame to match the existing deck and make the window walls in way that you can take down the windows in the summer. You could do it with metal latches or just build wooden tracks in your support pieces that allow you to slide in the windows and slide them out when you want to open it up.

There is something magical about a greenhouse roof over plants. Some thing that allows in lots of light but blocks the rain and hail and some of the wind. This is why hoophouses and high tunnels are so popular with small farmers - plants just do better with that tiny amount of protection. There is also something wonderful about air flow - which you will get plenty of by opening up the structure during the warm months.

Thanks trianglejohn. Both of your ideas sound great to me! Depending on the size I think I can make tracks inside the interior part to slide windows inside also to make a double-glass greenhouse. My yard is small and the location where it must be built will have tight spaces next to the house and existing deck. I want it built on its own support because my earthtainers are quite heavy. They are on my deck now with a plastic tent 'flowerhouse' over them for the last 2 seasons and the deck is slightly warped from all this weight. Anyhow due to the fit I will have to figure out where the openings will go for the glass windows to slide in. It will definitely be sequential and specific on how the pieces will fit in. I think your suggestion for the roof is wise and safer than using the windows.

Rain water needs to run completely off and not pool up anywhere, or else it will cause a host of problems. If you look at sky lights on building rooftops, they all have a dome built over them to make water run off.

Wow the corrugated plastic roof stuff is expensive. Three pieces comes to $100 at Lowes! I've got plenty of glass . I need to figure out how to make it work. Just downloaded Google Sketchup to play around with and try to model the design. I've got a better idea of lumber needed by drawing on paper, but would be cool to pay with a model.

Here is a link that might be useful: Google Sketchup

Wow the corrugated plastic roof stuff is expensive. Three pieces comes to $100 at Lowes! I've got plenty of glass . I need to figure out how to make it work. Just downloaded Google Sketchup to play around with and try to model the design. I've got a better idea of lumber needed by drawing on paper, but would be cool to pay with a model.

Here is a link that might be useful: Google Sketchup

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

I was at Lowes the weekend before this last one buying a bale of straw for decoration (garden use later) and right next to the storage truck there was a dumpster filled to the brim with random junk. On the top lay multiple 4X4ft sheets of thick 'cell' plastic sheeting. I don't know what it was originally used for (light fixtures maybe). Anyhow I snagged three panels and a smaller one. I am going to use these for an angled roof. This find is like $100 off my GH construction plan. The panels are sturdy, so I think they will do well and are light enough so as to not be dangerous.

I also had an idea strike me the other day.. the condensation drip from the AC line I extended into the garden from the side of the house wont be able to auto-water pole beans anymore because the GH is being built where my beans have always gone. Well... I think I will be able to dig down deep enough to bury a 55-gallon plastic drum that I currently use as one of my linked rain barrels. Why not bury it below the greenhouse deck and route the condensation drip line into it, so I can collect that water and pump it up as needed into the GH? I have both an electric pump and hand pump I can use.

Gorget about using the old windows on the roof. Lexan Corrugated with UV costing is about $50 for an 8' x 4' sheet. If you are going to invest $$$ and time building a greenhouse do it right the first time. You can use the windows onthe sides and ends if you want but the roof needs to be shatterproff (hail, fallen branches during a storm) and if it's single pane glass it could be dangerous.

Cole_Robbie and triangle_john are correct.

I'd agree with those cautioning about using the windows as a roof.

This is especially true if they are just plain glass, as opposed to tempered. Plain glass shatters into sharp fragments, which if on a roof then fall into the GH. This can be a dangerous or even deadly event if you happen to be inside during a hail storm or the like.

Single tunnel greenhouse,
with the width from 6m-10m .
length : 20m-100m ,
from China agrotime ltd,
and this model can apply in a lot of area ,
for the vergetable growing ,
with cheap price, and stable structre ,
can resitance to the strong wind and heavy snow ,
this model can have the ventilation area, with the insect install in the ventilation area, ,
also can fixed the colling system for the high tempreture area .