Tempered Glass Sources

Years ago I recall reading about making your own greenhouse from rejected tempered glass. I don't recall if it came from a book or an article, but the basic idea was that you find a place making tempered glass doors. Once there, you spoke to someone about purchasing tempered glass that had visual imperfections. Things where the glass remained sound, but had strange discolorations or slight visual warps. The writing noted that you can often get these rejected panels at deep discount. You then used this to create a small greenhouse. It seemed like a pretty decent idea.

My thoughts had been to perhaps use this method to create double-pane walls for an Oehler style underground greenhouse. While I don't currently live in a place where I can do any such thing, I am a heavy planner. One hiccup I had on this idea was that I have yet to find a place that works with Tempered glass that keeps their reject glass. I'm hoping someone else here has some experience either in the industry or with purchasing such things to give me advice on where I would be able to find such a location. Any advice or experience?

I don't know if you are near a city, but when I lived in Phoenix I talked to a guy that owns a glass company and he said he would give me as much tempered glass as I wanted.  I brought many sheets of it with me when I moved to WI.  This isn't glass with flaws in it, it's perfect sheets of glass.  I got glass in all different thicknesses.  Tempered glass can't be cut, so if it was ordered in the wrong size, it couldn't be used.  He had a giant rack of it and let me take anything I wanted.  I would just start calling glass companies.

In my community, it used to be the company that made sliding glass doors that offered seconds to the community at fantastic prices.  And they were double paned.

Storm windows are usually tempered too. When the little bits break off the corners, they're useless, so they end up at the recycling places when people throw them out.

They're not worth selling, but a want ad on Craigslist or similar might shake some loose out of the garages and barns where people have stacked them until they get around to throwing them away.

I know a guy in the glass biz too! I asked him about low iron tempered obscured glass and he wouldnt think of it! He said to get replacement glass for sliding glass doors.

It comes as a double pane, insulated type. He said that for $35-$40 you could have two sheets of glass after cutting them apart and that it was the cheapest way to buy glass for collectors and greenhouses.

At the time i was making thermal collectors and wanted 4x8' or 4x10' sizes and never did buy any. For greenhouse building, they should be great.

The solar thermal guy had a junkyard for solar and mechanical and him and i once built a chicken sun-house out of a scad of doorwall sections! Like 15' x 30'. I dont know how long it stood, but it was a funny,big cat in the hat looking greenhouse!

My source of cheap temperated glass is a Company that remodel facades. I Saw they remodeling the facade of a bank once and asked for the old glass. It turns out they were selling It very cheap. I then took note of their phone number and call them when i need a glass table top for the bamboo tables I make. I don't intend to build a greenhouse since I live in a tropical climate (Brazil),  I just need some glass for my tables.

Often aluminum framed single pane glass sliders are replaced with double pane vinyl ones and are available at repurpose stores.  There were six sets of them available when the people that bought the house my father had custom built himself remodeled it.  That is what my greenhouse is made out of.