I'm looking to build a coldframe or mini greenhouse for some of my delicate plants using some leftover wood I have. I'm in need of recommendations for affordable plastic sheeting or panes that can work well for this project. Any suggestions?
4 Answers
For a budget-friendly option, I’ve used white translucent floor protection sheeting—it’s like a twin-wall plastic and pretty cheap at about £5 for an 8x4 sheet. You could also use twin-wall polycarbonate roofing. While Lexan offers great light transmission, it can get pricey, so acrylic is a more affordable alternative. Just watch out for UV degradation; some plastics are treated to minimize this, so make sure that side is facing out.
Using plastic sheeting is a great choice—just staple it onto your frame! If you're near the Scottish Borders, I have some perspex lying around that I can give away for free!
4mm perspex sheets could cost you around £50 per square meter, which isn’t too bad considering they last forever. If you have a circular saw, cutting them to shape is easy, especially if you use the right blade. I just made a cold frame using an old perspex door, and it cuts quite simply. Cheaper options exist, but perspex is durable and outlasts the wood you frame it with, so it’s worth spending a little more.
You can find affordable replacement plastic covers for mini greenhouses that hold up for about five years if they're placed in a sheltered area. Just use the dimensions of your frame to figure out what you need. For a cold frame, it’s a good idea to line it with polystyrene from appliance packaging and use acrylic sheets for lids. Polycarbonate is better than acrylic since it’s less brittle, just be sure to avoid super thin materials—they won’t last long!
I’m considering using two layers of polyethylene for better insulation, one layer outside and another on the inside, creating a double-glazing effect. Thanks for the generous offer, but I'm not nearby.