Drafty Greenhouse

[grepmonkey]

Hi, I have a drafty greenhouse, due to missing plastic bits in the corners and replaced plastic panels that dont fit so well. I'm tempted to use some builders expanding foam to block the holes, but is that a bad idea?

I dont think im ever likely to want to move it, but I dont know if the foam is toxic in anyway.  Has any one got any views or advice?

[grepmonkey]

[davyw1]

Why cant you just replace the glass/perspex. If money is an issue then replace the south facing side with the glass from the north side, replce that with 1/4 inch plywood