Greenhouse roofing material?

[npaden]

I'm getting close to finalizing my plans for my shed/refugium/greenhouse setup and had a few more questions.

I plan on building a standard frame shed with a single slanted roof. I have a crappy pic that will help explain (maybe!)

(The brown rectangles are log siding to match the house)

I'm wanting to figure out exactly what to use for the roof. I've thought about framing up something with 2x6'x and 2x4's with a router groove for the greenhouse panels to slide in but wasn't sure of any other possible alternatives.

I'm going to insulate the walls of the shed so I don't want to loose all my benefit of insulated walls by having it all go through the roof so I've also thought about double panes on the greenhouse panels.

I'm pretty much clueless on greenhouse stuff so maybe there is something easy I can just slap up there!

I'm not opposed to using a metal frame if I can get it attached to the standard frame walls somehow.

Oh well, just hoping for some ideas.

Thanks in advance! Nathan

 

[liquid]

I know that Tropicorium in Michigan uses strictly semi-transparent plastic roofing sheeting for their greenhouse and that seems to work well for them even in the winter. I'd also talk to Joyfish on #reefs and see what she's using for her greenhouse. IIRC it's some sort of thermopane glass.

Shane

 

[rwoolley]

Sequentia makes a fiberglass corrugated roofing panel will filler strips, etc.
that can be bought at most lumber yards. Their website has directions.
http://www.kemlite.com/sequentia_corrug ... _index.cfm

 

[taikonaut]

Have you look into double-walled polycarbonate (Lexan?) panel that commonly used in green house construction?

 

[shr00m]

i always wondered why its not good to use glass in greenhouses???

 

[taikonaut]

'cause almost everybody throw stones...

sorry. Actually, one of the main reasons is that glass is awfully heavy and difficult to work with compare to plastic. Besides, it is not cheap either

 

[Fl_Seagull]

Glass is still used for greenhouses.

It is like the arguements over buying an acrylic or glass fish tank :wink: .

Plastic is winning currently since it is lighter, comes in a variety of panel types and easier to work with. While the high-end plastic panel are not cheap per sq ft, the installed cost can be less than glass.

 

[Len]

Copied to the DIY forum.

 

[Acrylics]

The "greenhouse" material made of polycarbonate can be had in several thickness from roughly 1/8"(3mm) to 1"(24/25mm) and either clear or translucent white and I believe some solar bronze colors as well. It's a double or triple walled and corrugated polycarbonate which is nearly unbreakable.
Look for names like Thermoclear and Macrolux as prolly the top two names in this material type.
If you need a bunch of it, call your local plastics distributor as probably the cheapest way of getting it. IIRC it comes in sheets up 4' x 20 or 24' sizes but you can also get 4 x 8' or 4 x 10' and is fairly cheap

HTH,
James

 

[taikonaut]

(or if you talk nicely to a green house owner, he/she may have a panel or two laying around that you can haul away for free )

 

[shr00m]

i dont understand how as much light gets through that translucent plastic stuff as glass though... is it still as good? isnt some needed light filtered out?

 

[npaden]

The colored plastic stuff does cut it down to around 50% or so. The clear is up around 90% though. (at least according to the specs I read)

 

[Anonymous]

I have done quite a bit of research on greenhouse glazing as it pertains to growing coral. You need the UV band of light to make corals fluorescent. Glass as well as most other glazing removes or filters UV light. So to get the colors they want, some greenhouse growers, use MH lights just before sale to color up their corals. The poly plastic does not filter out UV and this is what I intend to use. It needs to be replaced often, but yields maximum light and is not UV filtered. I won't need any supplemental lighting.

 

[Acrylics]

The poly plastic does not filter out UV and this is what I intend to use. It needs to be replaced often, but yields maximum light and is not UV filtered.

Make sure of the brand you buy then, 'cuz most of the twinwall polycarb does have a UV coating on one side that will filter UV.

James

 

[npaden]

I'm not planning on growing any sps or anything in there. Maybe some soft corals and algae.

Nathan

 

[Anonymous]

The poly plastic does not filter out UV and this is what I intend to use. It needs to be replaced often, but yields maximum light and is not UV filtered.

Make sure of the brand you buy then, 'cuz most of the twinwall polycarb does have a UV coating on one side that will filter UV.

James

I was thinking about two layers and a blower. I was thinking of the better insulation and permenance until I read Calfo,s book. He suggested that I use the no UV blocking material and it would also be short lived. Are there other suggestions?

 

[Acrylics]

I was thinking about two layers and a blower. I was thinking of the better insulation and permenance until I read Calfo,s book. He suggested that I use the no UV blocking material and it would also be short lived. Are there other suggestions?

There are double layered or "triple walled" greenhouse materials available in thicknesses 32mm. It's essentially like taking two sheets and laminating them together but the center layer will have the same thickness (.020-.030") as the outer layers. I can't see why he'd say it would be short lived though. Plastics have come a long way in the last few years with regard to UV degradation as Cadmium and other similar binders have been either removed or refined. Most mfrs will actually guarantee their materials to not break down or yellow (due to UV) for 5-10 yrs and in some cases for life.
For some light reading: http://www.gestructuredproducts.com/sp1 ... chmode=dst
I'll call on Monday to see if it offered without the UV coating. I can't say how much of the UV will be filtered out by these products as is though. As you know, UV filters do not *necessarily* filter *all* UV though some will come pretty darn close.

James

 

[npaden]

Okay, I went to Home Depot today and they have a 26"X12' clear poly carbonate corrugated sheet for $25. They also have a clear PVC corrugated sheet for $15.

Why not just double these up for strength, one on the top of a 2x4 frame and one on the bottom? This would do well for light transference and do pretty well for insulation at the same time?

Thanks, Nathan

 

[Acrylics]

Sure, that would do just fine

James

 

[Anonymous]

I was thinking about two layers and a blower. I was thinking of the better insulation and permenance until I read Calfo,s book. He suggested that I use the no UV blocking material and it would also be short lived. Are there other suggestions?

There are double layered or "triple walled" greenhouse materials available in thicknesses 32mm. It's essentially like taking two sheets and laminating them together but the center layer will have the same thickness (.020-.030") as the outer layers. I can't see why he'd say it would be short lived though. Plastics have come a long way in the last few years with regard to UV degradation as Cadmium and other similar binders have been either removed or refined. Most mfrs will actually guarantee their materials to not break down or yellow (due to UV) for 5-10 yrs and in some cases for life.
For some light reading: http://www.gestructuredproducts.com/sp1 ... chmode=dst
I'll call on Monday to see if it offered without the UV coating. I can't say how much of the UV will be filtered out by these products as is though. As you know, UV filters do not *necessarily* filter *all* UV though some will come pretty darn close.

James

My understanding was the longer life was do to UV blockers. With it the plastic had longer life and less UV to the greenhouse. So the plastic with no UV blockers lasted only 1-2 years.