Greenhouse plastic is a suitable solution for covering your greenhouse, as it acts as a vapor barrier to prevent moisture diffusion through roofs, walls, and floors. There are four recommended types of plastic for greenhouse coverings, which can last for three years or more unless damaged by extreme weather conditions or other reasons. Vapor barriers are low-permeable materials used to control or regulate moisture in a greenhouse. They are essential for protecting materials that are permeable to water vapor and can help prevent heat loss to the ground underneath and beside the greenhouse.
Concrete offers the advantage of being easier to clean but is not ideal for preventing pools of water from forming in the growing area. It often warrants under slab vapor barrier solutions. Outdoor greenhouse plastic sheeting is purpose-built for this purpose.
Greenhouse plastic offers some UV protection and some versions have better tensile strength than others. However, plastic ripping where the plastic touches PVC is a concern. Some people recommend using vapor barriers as they stand up to hail better, are cheaper, easier to work with, and can be dealt with in sections. They are protected with ultra violet inhibitors to prevent sun damage.
The most logical and easiest to implement technique is using a technique similar to a vapor barrier on a house. Plastic sheeting used in construction should not be used for greenhouse applications, as greenhouse coverings have similar differences. For more permanent greenhouses, woven polyester is worth every penny. The choice depends on what you want to contain, such as heat and humidity. 6 mil HDPE film should work well for greenhouses.
📹 Why you must have Vapor Barrier
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📹 Moisture Problem in the Greenhouse
I didn’t install a vapor barrier in the greenhouse ceiling. That was a mistake. In the winter, humidity can condensate on the …
I appreciate your making this article to help keep others from having the same problems you have with this issue. It says a lot to your character, also your article is clear and direct to the point. BRAVO!, that said, many people have had issues with earthships leaching toxic chemicals into the home and even making it unlivable because of the offgasing produced when the tires break down. Have you experience any health issues, do you live in your earthship full time, if so how long have you been there, and do you have any updates to your humidity problem or any other problems you have encountered since 2014 when this article was made. I see you have started building another earthship? home. How much time have you actually spent actually living in an earthship? I have built my own traditional Monolithic home. I have the outside done and about half the inside done. I am currently living in my home. In my experience.. if I had it all to do over again, I would build a shop first. I have all my tools in the house with me and no storage. I am interested in a “food forest” also, not so overgrown and let go as many have done. I’ve planned and started growing all my fruit trees so I wouldn’t have to wait so long for them to actually produce.
Your best bet is to put like 1cm claymix(not cement!) on the wood. Clay can soak up alot of moisture and then let go of it when the air is drier. Plastic wont solve the problem with condensation on the windows. Its a construction error that is well known and documented here in Europe. And if you read basic building engineering you can figure it out just by looking at the construction. Nice article though and I appreciate your honesty. Keep it up 🙂
Moisture problem can have several sources where the insulation is weak enough for the cold outside temperaure to cool the inside humid air below dew-point. Tipically: window surface, roof with isufficent insulation, top of vent chimney. The vapor barrier sheets only prevents the inner structure of the roof of beeing wet, but does not solve the moisture issue. Additional insulation, or controlled moisture collection (ie. with recuperator) is the only way.
You will continue to have moisture built up in that room despite your efforts. Ventilation is what will fix this. I know you want to retain heat but the air (and moisture) need to escape. Vapor barriers do not prevent moisture build up. They protect materials from the moisture that is present. Like you said, your garden is creating the moisture. Keep your windows cracked open a bit and/or devise a way to exhaust some air out of that space.
Buddy, the solutions is simple to your condensation issues. You need to avoid evaporation. How to do it is simple, here in Australia we water our plants seldomly to encourage deep roots. This will refude the amount of gaseous water in the air. Noe the next issues is how to avoid liquid water to turn into gas. Simple, when you water the plants move the mulch (this is what avoids evaporation) around the plants before watering and once you are done you cover the root system to block water evaporation. Of course this tedious exercise can be minimised during the summer periods. Good Luck :))