Condensation in a Poly-tunnel Greenhouse

[Ross365]

Last summer, I bought a 6 x 10' polytunnel, not to use as a greenhouse, but as a cheap (I think it was £50) way of geting some extra storage. This has worked out badly; even during the summer it was usually lined internally with condensation and it's worse in winter. Going in there today, a plastic container on the floor had a couple of mm of water in it. I tried installing some ventillation in it, but it's not had a significant effect. It greatly limits what you can store in there.
Anyone got any ideas on how to reduce the problem?

 

[Bullet2012]

whats the base it covering ?

 

[Redsailor]

I have used a layer of large bubble wrap under the polytarp on a polytunnel framework. That with good ventilation helps eliminate or reduce condensation.

 

[Ross365]

The base is just dry earth; I realise that's the least good option, but short of putting down some concrete, I'm not sure what a cheap/easy alternative would be.

Re the bubble wrap, yes that sounds like a useful improvement! What did you do in terms of good ventilation?

 

[knighty]

how do you setup the ventilation?

I've never seen it in person... but I thought a lot of people used polly tunnels for drying logs, wood on pallets so it's up off the floor and a 6 inch gap all around the polly tunnel so it's off the floor too?


I was planning to do the same thing myself....

 

[gaz1]

if you want less condensation double plastic it as it creates double glazing

 

[rtcosic]

Cover the earth with an impermeable membrane.

 

[CompoSimmonite]

I'd just cover whatever is being store with a tarp to protect it from condensation drips if this a temporary store

 

[Dapph2]

Get a decent 24/7 through flow of ventilation the ground is sweating and the evaporation is condensing on the cold plastic . Perhaps make some half doors for each end and find a way of keeping them securely pegged open .
Make the doors so the hinge side is to the worst prevalent weather if your able to as this will give a bit of shelter too.

My mate Don was a small holder who lived off selling his small holdings produce , he had nine big 20 foot wide tunnels some 50 feet long . He erected hit and miss walls on 6 to 9 inch dia, ex telegraph poles cut down to 10 foot lengths set in 4 feet of soil and back about 6 foot or so from the ends to help stop getting wind drive rain blown in He had builders green netting across the doors most of the day & night but closed up on growing crops if the temp dropped to 9 oC or below at night .

 

[Gragson]

Last summer, I bought a 6 x 10' polytunnel, not to use as a greenhouse, but as a cheap (I think it was £50) way of geting some extra storage

For growing fruit/veg, for storing anything, daft idea

 

[jo1010]

Doors/openings at both ends so air can go straight through and ventilate. Cover ground with either stone chippings or mulch of some kind. There's a poly tunnel here like that and has little condensation.....BUT for dry storage of items it wouldn't offer much advantage other than keeping the rain off....the UK is a very humid place

 

[Bullet2012]

the UK is a very humid place

94% according to my weather station -1c temperature, today at 10:50

 

[Ross365]

Thanks for the various comments. I did start to add some ventillation at one end using a stainless steel "sink strainer" about 160x130mm, bought very cheaply on ebay -see pic.. I need to fix one in at the door end, but the "door" opens by being folded upwards, i.e. it has zips down both side of it. I'll add some bubble wrap too. However, I'm leaning towards Gragson's comment that small, inexpensive poly tunnels are "For growing fruit/veg, for storing anything, daft idea" .