• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • Anne Miller
  • Mike Haasl
  • Pearl Sutton
  • paul wheaton
stewards:
  • r ranson
  • Burra Maluca
  • Joseph Lofthouse
master gardeners:
  • jordan barton
  • Leigh Tate
  • Carla Burke
gardeners:
  • Greg Martin
  • Jay Angler
  • John F Dean

insulated concrete tarps/blankets for high tunnels?

 
master pollinator
Posts: 184
Location: KY - Zone 6b (near border of 6a), Heat Zone 7, Urban habitat
75
monies home care fungi foraging plumbing urban food preservation bee building homestead ungarbage
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Has anyone used insulated concrete tarps/blankets for retaining heat at night in high tunnels? Thoughts?
 
pollinator
Posts: 2370
Location: 4b
606
dog forest garden trees bee building
  • Likes 3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I would want some easy method to roll them up or fold them to save doing it manually each morning and evening, but I can't see why it wouldn't work.
 
gardener
Posts: 4322
Location: Pacific Wet Coast
1597
duck books chicken cooking food preservation ungarbage
  • Likes 3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I've seen pictures of thick straw covers on Chinese greenhouses, but I got the impression that they didn't roll them up every morning - it was an infuriatingly vague reference.

That said, #2 Son explained to me that due to the way heat moves through glass, if I wanted to insulate a small greenhouse, I would be much better to have insulation on the *inside* to stop the heat from getting through the glass. The danger of this would be the humidity freezing on the glass and then melting the next day which could result in water where one doesn't want it. So much depends on climate - when we lived in Ottawa, this would be a serious issue, but here on the Wet Coast, I can probably design things so the water drained to a suitable location. My sister has some outside metal roller blinds that she puts up and down with the turn of a handle. She can use them to stop sun in the summer as well, and she feels that even though they are by no means perfect, they were worth the cost.
 
pollinator
Posts: 3734
Location: Kansas Zone 6a
156
  • Likes 4
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Downsides I see are weight and cost.  Cost can be overcome if bought used.  But the weight issue will probably mean you will need a few extra heavy row hoops or more of them.  

One positive/negative is the total light occlusion if you don't pull it off at daybreak.  Could lose valuable light, could prevent baking as more people lose plants to overheating than freezing by getting busy/lazy and not pulling the covers quick enough in the morning.
 
echo minarosa
master pollinator
Posts: 184
Location: KY - Zone 6b (near border of 6a), Heat Zone 7, Urban habitat
75
monies home care fungi foraging plumbing urban food preservation bee building homestead ungarbage
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I have seen some listed that were nearly the same weight as the plastic sheeting. I've seen references to double-walled plastic for high tunnels and that too would add weight. As for losing early light, that would also be a time of greatest heat loss (coldest part of the day). It takes a bit for sun to reach my yard as well. Not arguing, but bouncing thoughts off of y'all.
 
pollinator
Posts: 365
98
  • Likes 3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Jay Angler wrote:I've seen pictures of thick straw covers on Chinese greenhouses, but I got the impression that they didn't roll them up every morning - it was an infuriatingly vague reference.

That said, #2 Son explained to me that due to the way heat moves through glass, if I wanted to insulate a small greenhouse, I would be much better to have insulation on the *inside* to stop the heat from getting through the glass. The danger of this would be the humidity freezing on the glass and then melting the next day which could result in water where one doesn't want it. So much depends on climate - when we lived in Ottawa, this would be a serious issue, but here on the Wet Coast, I can probably design things so the water drained to a suitable location. My sister has some outside metal roller blinds that she puts up and down with the turn of a handle. She can use them to stop sun in the summer as well, and she feels that even though they are by no means perfect, they were worth the cost.



This 2015 article from Low Tech Magazine gets into some of the details and sources of various designs and includes an image where inner and outer mats are deployed at night to minimize radiation loss of heat.
 
Jay Angler
gardener
Posts: 4322
Location: Pacific Wet Coast
1597
duck books chicken cooking food preservation ungarbage
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
James Whitelaw wrote:

This 2015 article from Low Tech Magazine gets into some of the details and sources of various designs and includes an image where inner and outer mats are deployed at night to minimize radiation loss of heat.

Great article, James! Picture "C" in the first group of 4 pictures, shows a doubled roof truss system where the insulation can be rolled down easily on the inside of the plastic film.

I understand the article's point about the cost/benefit of plastic film over glass, and I understand that special greenhouse plastics are being developed that last longer, but I still wonder about the "cradle to grave" costs of plastic when one adds the cost of disposal?  

The OP specifically is asking about insulated concrete curing tarps. This company - https://www.tarpsnow.com/concrete-curing-blankets.html - states that these tarps have water phobic insulation and use tough material for "extended longevity" - but what does that mean? Rolling them up during the day will protect them from solar UV which is hard on tarps. If they were on the inside of the greenhouse cover such as in picture "C" in  the article James linked to, damage from wind buffeting would be non-existent, but if it was rolled down on the outside, it might go through a lot of freeze/thaw cycles which could damage it. I find things don't like to flex as much the colder they are. They look like an interesting possibility, but I worry about what will happen when they get old and whether there will be any options for recycling.
 
Proudly marching to the beat of a different kettle of fish... while reading this tiny ad
100th Issue of Permaculture Magazine - now FREE for a while
https://permies.com/goodies/45/pmag
reply
    Bookmark Topic Watch Topic
  • New Topic