Vinyl houses

Finding land, working a small plot or anything else countryside related
User avatar
gonbechan
Founder
Founder
Posts: 1143
Joined: Wed Sep 23, 2015 9:10 am
Has thanked: 876 times
Been thanked: 394 times

Vinyl Houses

Post by gonbechan » Thu Jun 08, 2017 9:31 am

I am already subscribed to his channel! :D

Personally I lust after a sunken greenhouse which I presume if done well, would be strong against typhoon.

And yes, after posting that second video, I watched it again and could imagine it lifting off in the typhoon and sailing across the neighbourhood.

User avatar
Zasso Nouka
Tech Support
Tech Support
Posts: 2296
Joined: Wed Sep 23, 2015 9:37 am
Location: Chiba Prefecture
Has thanked: 1245 times
Been thanked: 870 times
Contact:

Vinyl Houses

Post by Zasso Nouka » Fri Jun 09, 2017 5:46 am

Was watching Curtis Stone's channel almost non stop yesterday while packing veggies in the shed, there's so much useful information in them it's incredible. Getting lots of great ideas we may be able to use and others that may need a little adapting to the Japanese climate.
gonbechan wrote:Personally I lust after a sunken greenhouse which I presume if done well, would be strong against typhoon.
I think if you adapt a Japanese vinyl house you should be fine. The arch structure they use is an incredibly strong shape at resisting outside pressure and when you can get an unused one for free they get even better. We have four poly tunnels now and all of them were free of charge.

paradoxbox
Posts: 261
Joined: Wed Sep 30, 2015 11:52 pm
Has thanked: 108 times
Been thanked: 321 times

Vinyl Houses

Post by paradoxbox » Fri Jul 21, 2017 2:00 am

Zasso Nouka wrote:Was watching Curtis Stone's channel almost non stop yesterday while packing veggies in the shed, there's so much useful information in them it's incredible. Getting lots of great ideas we may be able to use and others that may need a little adapting to the Japanese climate.
gonbechan wrote:Personally I lust after a sunken greenhouse which I presume if done well, would be strong against typhoon.
I think if you adapt a Japanese vinyl house you should be fine. The arch structure they use is an incredibly strong shape at resisting outside pressure and when you can get an unused one for free they get even better. We have four poly tunnels now and all of them were free of charge.
Aerodynamic Nerd alert:

The arch shape is strong but it also produces lift, or to be clearer, negative lift. If you look at an airplane wing you'll see the top section is basically an arch. Actually what you get is a low pressure zone above the arch section, and the boundary layer of air blowing over it starts to break up and become turbulent just past the apex of the arch. So wind blowing over the greenhouse actually sucks it down onto the ground with more force than the beams holding it in place.

The downside to this of course is if your greenhouse develops a gap in the vinyl somewhere, especially near the bottom. If it does, air will flow to the underside (higher pressure) and the result is an airplane greenhouse. And if the vinyl is loose or very dirty, the drag from friction could exceed the negative lift and then you'll get severe flutter, tearing or it might even just lift up and fly off.

How do your greenhouses withstand winds coming from the entrance sides?

I also lust after a partially underground greenhouse like gonbechan but would probably settle for a stone windbreak around the house if I were living in a place like Miyazaki or Okinawa with big winds. Dealing with floodwater seems like it might be a problem too, unless you built a large water collection cistern to handle it all.

User avatar
Zasso Nouka
Tech Support
Tech Support
Posts: 2296
Joined: Wed Sep 23, 2015 9:37 am
Location: Chiba Prefecture
Has thanked: 1245 times
Been thanked: 870 times
Contact:

Vinyl Houses

Post by Zasso Nouka » Fri Jul 21, 2017 6:28 am

Not sure about Okinawa but in Kyushu most farmers take off the vinyl as the typhoon season approaches to avoid having it ripped off as they catch a lot more typhoons down there and they tend to be quite strong when they first hit land.. When I first started farming I was getting a lot of advice from a friend down that way and he was really surprised that here in Kanto we leave the vinyl on for several years before changing it.

Normal preparation for an incoming typhoon is to repair any nicks or cuts to the vinyl and make sure all the bindings are secure. However even then you can get damage and it's not unusual to see one or two houses with the vinyl partially ripped off after a typhoon. The bindings help a lot and generally confine the damage to part of the house rather than having all the vinyl stripped off. Winds coming towards the doors don't seem to be a major problem, either doors are sliding types or hinged ones open outwards. There are gaps around the edges but this doesn't seem a major problem.

Snow damage is another thing to consider, if you live in an area with lots of snow then the vinyl comes off before winter. Unless the house is heated. Never had flood damage but then we live on top of a hill so that maybe something to consider if your vinyl house is located in a dip or something. Personally I favour having vinyl houses sited at ground level otherwise young plants at the edges might struggle for light when they are small but if you aren't growing right up to the edges that may not be a factor.

We recently purchased PO film for one of our vinyl houses instead of the usual vinyl as it is much less environmentally damaging. Apparently vinyl contains lots of chlorine, phthalates and a whole host of other potentially unpleasant additives. Haven't put the PO film on a house yet but if it is as effective as vinyl then we plan to switch over entirely to PO film, it is slightly more expensive than vinyl but no much more.

User avatar
Zasso Nouka
Tech Support
Tech Support
Posts: 2296
Joined: Wed Sep 23, 2015 9:37 am
Location: Chiba Prefecture
Has thanked: 1245 times
Been thanked: 870 times
Contact:

Re: Vinyl houses

Post by Zasso Nouka » Wed Dec 12, 2018 2:22 pm

We've now moved most of our vinyl houses over to PO Film rather than polyvinyl chloride film (or vinyl) for several reasons. Mainly because vinyl doesn't last very long and we became seriously bored of having to replace all the plastic every other year, when vinyl fails it tends to unzip right down the length of the vinyl house so once it gets weak the whole thing can just unzip. PO film tends to have a longer life and doesn't always fail in such a catastrophic manner so you can sometimes make repairs that will buy you some time till it's more convenient to replace the whole lot or cut out the affected part and just replace that.

Also vinyl contains some rather unsavoury chemicals including phthalates and other plasticisers that can be released into the environment over the lifetime of the film and make it somewhat harder to recycle, also these plasticisers make vinyl more tacky so that dirt and algae stick to it more readily and can lead to some of the structural weaknesses it gets. PO film doesn't have any of those plasticiers so is much easier to clean and is also much easier to recycle.

We're currently using some of the light scattering PO films as they cut down on hot spots inside the house and have a much better spread of light inside the tunnel. They are more expensive than ordinary films but the cost seems justified

You should be able to order PO from your local agricultural supplies shop or there is a good online seller here Miyata Bussan

Given how much of a pain it is to replace the side sheathing at ground level I'd recommend going with the 'Tough Side' PO film as it should mean you are replacing that less regularly than the main roof.

Post Reply