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Plastic tent platforms are madness

PostPosted: Fri 07 May, 2021 7:04 pm
by deadwood
I'd be surprised if this hasn't already been raised in the forums, but I couldn't quickly find it. I'm just back from the Walls of Jerusalem doing a 6 day guided walk and at the campsite at Wild Dog Creek, there was a mix of timber and plastic pseudo-wood tent platforms. I can see how someone in an office might have thought the plastic was a good idea, but really they should think again. We were at this camp-site 2 nights and the first night there was some light precipitation - no worries - tent was good quality. Getting back to our tent after the next days day walk however, all the tents on the plastic platforms were full of water from condensation. No problems at all for the wooden platforms where the timber had allowed the moisture to soak in and dry. Our tent was particularly bad because the platform had a presumably non-slip grooved surface that meant it held even more water and never dried. The second night was frosty cold resulting in the moisture under the tent freezing tents and footprints to the platforms.

If are ever confronted by a plastic tent platform, don't leave your tent pitched during the day and ideally choose a timber platform instead.

Re: Plastic tent platforms are madness

PostPosted: Sat 08 May, 2021 8:36 am
by rcaffin
A rather odd situation, and rather complex.

all the tents on the plastic platforms were full of water from condensation.
That is rather strange. I will assume that 'full of' really means there was some water on the floor of the tent. Anything more than that would mean someone had been there with a bucket ...
Why would there be condensation inside an unoccupied tent? I can imagine a teaspoonful maybe from the air within, but no more than that - assuming the tent had been closed up while the walkers were away. If the tent had been left open then maybe rain had come in.

Our tent was particularly bad because the platform had a presumably non-slip grooved surface that meant it held even more water and never dried.
Um - I don't see the relevance here. Assuming the floor of the tent was waterproof, why would water under the tent cause any water inside the tent? Unless of course the floor was seriously not waterproof - which could happen. But that would mean the tent was not 'good quality'.

The second night was frosty cold resulting in the moisture under the tent freezing tents and footprints to the platforms.
OK, that one is a bit funny, or a special case. Even so, I am puzzled. We have slept on very cold snow and the tent was never stuck to the snow underneath in the morning. There are two reasons for that of course: the first is that our warmth from inside the tent limited the cooling of the floor; the second and far more important reason is that coated fabric in good condition should not really stick to ice. Well - not much anyhow.
5621c.jpg
5621c.jpg (63.12 KiB) Viewed 4012 times


I wonder whether the tent floors were all that good? If they were aging and porous both problems could be explained in one go. Were the tents provided by the guiding company, and getting a bit past their prime? Perhaps they were made from old PU-coated fabric, which is a bit notorious for problems like these.

Cheers
Roger

Re: Plastic tent platforms are madness

PostPosted: Sat 08 May, 2021 10:59 pm
by wildwanderer
Dam thats a good looking tent Roger..

Deadwood as Roger mentioned it's likely the issue is a porous tent floor due to age, abrasion or quality. A well shaped ground sheet can help.

If it was a tent supplied by the guiding company I'd chat to them about it as sounds like the experience put a dampner on your trip.

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 8:27 am
by rcaffin
Dam thats a good looking tent Roger..

MYOG effort.
3-pole single skin for 3 season, but this 4-pole double skin one for winter. It survived (easily) a night of 100 kph storm on top of the Main Range in the snow. No worries at all. Mind you, I was crawling while pulling the tent down in the morning: couldn't stand.

Cheers
Roger

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 8:54 am
by matagi
rcaffin wrote:
Our tent was particularly bad because the platform had a presumably non-slip grooved surface that meant it held even more water and never dried.
Um - I don't see the relevance here. Assuming the floor of the tent was waterproof, why would water under the tent cause any water inside the tent? Unless of course the floor was seriously not waterproof - which could happen. But that would mean the tent was not 'good quality'.

Cheers
Roger

Actually, I could see where a problem with condensation inside the fly would arise in this situation, especially if it was sunny and would have nothing to do with the porosity of the inner floor.

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 9:25 am
by rcaffin
Actually, I could see where a problem with condensation inside the fly would arise in this situation, especially if it was sunny and would have nothing to do with the porosity of the inner floor.

Well, I can NOT.
I would never expect condensation inside a tent when it was sunny. Condensation on a sun-warmed fly fabric?

Cheers
Roger

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 12:18 pm
by stry
rcaffin wrote:
Actually, I could see where a problem with condensation inside the fly would arise in this situation, especially if it was sunny and would have nothing to do with the porosity of the inner floor.

Well, I can NOT.
I would never expect condensation inside a tent when it was sunny. Condensation on a sun-warmed fly fabric?

Cheers
Roger


Depends. If the vestibule is open on the bottom, and the surface on which it is pitched is holding a lot of moisture, condensation is possible.

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 12:32 pm
by rcaffin
If the vestibule is open on the bottom, and the surface on which it is pitched is holding a lot of moisture, condensation is possible.

I would dispute that, on the basis of 50+ years of experience, plus the laws of physics (and a PhD in science).
You can only get condensation when the surface involved is colder that the saturation temperature of the prevailing atmosphere. With sun warming a tent fly above ambient, that is not going to obtain.

Now, if there was no sun but a cold wind blowing, to chill the fabric down, and wet grass inside the vestibule - that would be possible.

Cheers
Roger

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 6:11 pm
by matagi
rcaffin wrote:
Actually, I could see where a problem with condensation inside the fly would arise in this situation, especially if it was sunny and would have nothing to do with the porosity of the inner floor.

Well, I can NOT.
I would never expect condensation inside a tent when it was sunny. Condensation on a sun-warmed fly fabric?

Cheers
Roger

I was thinking along the lines of a solar still type effect.

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 7:19 pm
by clarence
I agree Deadwood. The reconstituted plastic materials will not absorb water. They also form a flatter surface than timber on average. As a result water on the plastic platform can pool and move a long way under the tent floor by capiliiary action. Generally speaking timber will be more absorbent and has imprefections that limit the continuity of the capilliary plane.

Water may get through the tent floor, or may even stay as pools on the floor of the vestibule.

During the day, sun can warm the tent, causing the air in the tent to absorb this moisture as the dewpoint of the air is increased greatly (i.e. warm air can hold a lot more water than cold air).

This energised air causes water vapour to increase in the tent space during a warm day.

If this air volume cools, once the sun goes down (for example), water could fall out of the air in the same way dew does on a cold night.

Totally possible in the right conditions.

Clarence

Re: Plastic tent platforms are madness

PostPosted: Sun 09 May, 2021 11:12 pm
by Neo
Apparently the plastic-wood product kind of explodes when a bushfire comes through.
There was a case of a viewing platform at an indigenous rock site two summers ago. The site had obviously lasted many thousands of years of harsh weather and fires, but got damaged by molten plastic.

Re: Plastic tent platforms are madness

PostPosted: Tue 11 May, 2021 9:28 am
by grunter
https://www.abc.net.au/news/2020-01-08/ ... e/11848938 yes it happened at Carnarvon Gorge.

Re: Plastic tent platforms are madness

PostPosted: Tue 11 May, 2021 12:18 pm
by stry
rcaffin wrote:If the vestibule is open on the bottom, and the surface on which it is pitched is holding a lot of moisture, condensation is possible.

I would dispute that, on the basis of 50+ years of experience, plus the laws of physics (and a PhD in science).
You can only get condensation when the surface involved is colder that the saturation temperature of the prevailing atmosphere. With sun warming a tent fly above ambient, that is not going to obtain.

Now, if there was no sun but a cold wind blowing, to chill the fabric down, and wet grass inside the vestibule - that would be possible.

Cheers
Roger


Thanks Roger. My recollection may be more in line with your last sentence. Although it was very hot and humid under the fly, with moist grass, it may not have been sunny.

Re: Plastic tent platforms are madness

PostPosted: Thu 13 May, 2021 10:55 am
by Scottyk
Tent condensation is is the result of humidity and dew point.
What causes those two factors to be ideal for water to condensate on your tent walls is the important bit.
I think plastic platform would make almost zero difference.

Re: Plastic tent platforms are madness

PostPosted: Thu 13 May, 2021 11:04 am
by Casparvitch
Yeah I would expect water on top of plastic platform has the same result as was absorbed by wooden platform.

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 10:13 am
by Nuts
I've not seen the new platforms. Was the grass cleared to build them or still dying off underneath?

It sounds odd to me as well but it's easier to dismiss than to exhaust the subtlties, the park service would be better off knowing than not, before building more.

A leaky floor sounds possible but would imagine that would be noticeable, and most prevalent around the edge of a tent pitched firstly on a dry platform?



Deadwood could also have a phd or even be an experienced walker.

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 10:25 am
by Warin
Nuts wrote: have a phd or even be an experienced walker.


Neither of those exclude gross errors. :?

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 3:54 pm
by icefest
rcaffin wrote:
5621c.jpg



is that the suluk ice axe?

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 4:40 pm
by rcaffin
Yes, Suluk ice axe.

Cheers
Roger

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 7:14 pm
by deadwood
Just to clarify a few points:-
  • max temp was around 10 degrees
  • According to the BOM humidity barely dropped below 100% during the day
  • There was only a few patches of sun
  • The photo of the tent in the snow on a nice sunny day is nothing like the weather conditions we had
  • The cold plastic slab of the platform would also have been insulated above by sleeping mats and nice thick down sleeping bags.
  • three tents (all different, not all provided by the company) were pitched on the plastic platforms, all had condensation on the floor
  • 4 tents were pitched on wooden platforms, none had the condensation issues.
  • The tents pitched on the wooden platforms also had the advantage that when they were packed up, they were dry underneath.
  • The tent we used, we also pitched on wet ground and had no issues
If you are happy to pitch your tent on a plastic platform in cold humid conditions, be my guest - less competition for the wooden ones if there are any.

Re: Plastic tent platforms are madness

PostPosted: Fri 14 May, 2021 10:16 pm
by clarence
Scottyk wrote:Tent condensation is is the result of humidity and dew point.
What causes those two factors to be ideal for water to condensate on your tent walls is the important bit.
I think plastic platform would make almost zero difference.


Yes, condensation is the result of humidity and temperature. These two will determine the dew point (the temperature where that air reaches saturation and condenses).

The thing is that many factors will affect the humidity and temperature (and therefore dewpoint). These can rise and fall over time (e.g. day to night) and also vary from one system to another (inside a tent vs outside)

I would argue that material properties of timber vs plastic (e.g. absorption and adsorption properties; vapour permeability; hygroscopic storage capacity and ability to hold surface water) would be enough to make noticeable differences.

It only takes a relatively minor change in one factor to create very different results.

Psychrometrics a fascinating area, and has a lot of relevance ot outdoor activities -e.g. howvapour barrier liners keep warmth in, and why the foot of your sleeping bag gets wet on a cold night in a tent

When I'm on a tent platform next I'll take deadwood's advice and pick the timber one.

Clarence

Re: Plastic tent platforms are madness

PostPosted: Sat 15 May, 2021 8:41 am
by Nuts
deadwood wrote:Just to clarify a few points:-
  • max temp was around 10 degrees
  • According to the BOM humidity barely dropped below 100% during the day
  • There was only a few patches of sun
  • The photo of the tent in the snow on a nice sunny day is nothing like the weather conditions we had
  • The cold plastic slab of the platform would also have been insulated above by sleeping mats and nice thick down sleeping bags.
  • three tents (all different, not all provided by the company) were pitched on the plastic platforms, all had condensation on the floor
  • 4 tents were pitched on wooden platforms, none had the condensation issues.
  • The tents pitched on the wooden platforms also had the advantage that when they were packed up, they were dry underneath.
  • The tent we used, we also pitched on wet ground and had no issues
If you are happy to pitch your tent on a plastic platform in cold humid conditions, be my guest - less competition for the wooden ones if there are any.


It's a new product, so there are no experts with a long experience in the same conditions.

I'm happy to do so.. but I'm sure P&W could benefit from your contact and direct experience (as could we all, when these roll out around tracks).

Great Western Tiers Field Office
PO Box 13
Deloraine TAS 7304
Phone:
03 6701 2104

Email:
GreatWesternTiers@parks.tas.gov.au

Re: Plastic tent platforms are madness

PostPosted: Sat 15 May, 2021 6:15 pm
by icefest
clarence wrote:why the foot of your sleeping bag gets wet on a cold night in a tent

Isn't that just because it's touching the tent wall?

At least, it only happens to me when my bag does. :/

Re: Plastic tent platforms are madness

PostPosted: Sat 15 May, 2021 8:01 pm
by north-north-west
icefest wrote:
clarence wrote:why the foot of your sleeping bag gets wet on a cold night in a tent

Isn't that just because it's touching the tent wall?

At least, it only happens to me when my bag does. :/


No, it's complex matter. Sweat, dew point, etc. Feet have large surface area, small volume, so they perspire more. But there's more dead air space in the footbox than the rest of the bag, so there's less heat transfer to the outside of the bag. Thus, condensation. (This is the short version. There's a multi-page thread about it somewhere on the forum.) I've started doing the vapour barrier inside the fluffy socks thing now, and voila! no more damp-ended bag/quilt.

Last page of this has a longish post from jdeks which covers it:
http://bushwalk.com/forum/viewtopic.php?f=15&t=28206&p=355324&hilit=condensation+foot+sleeping+bag#p355324

Re: Plastic tent platforms are madness

PostPosted: Sat 15 May, 2021 8:14 pm
by Warin
north-north-west wrote: I've started doing the vapour barrier inside the fluffy socks thing now, and voila! no more damp-ended bag/quilt.


Are the fluffy socks damp in the morning? Do the fluffy socks manage to dry out before the next nights use?

:?: But more important, are the feet warm?!

Re: Plastic tent platforms are madness

PostPosted: Sun 16 May, 2021 4:34 pm
by north-north-west
Bread bags over the socks and the socks are damp in the morning, hence the bags now going against the bare skin and the socks over that. Warmer, dry socks, dry quilt/bag. Downside is it might take a bit of getting used to having the plastic against the skin (it does feel weird at first, especially if you have oversensitive feet). If so, maybe a thin pair of socks inside the bags and the warm ones outside.

Re: Plastic tent platforms are madness

PostPosted: Mon 17 May, 2021 2:30 pm
by Biggles
Did the OP have the tent vents open during the time they were away on their day walk, returning to camp to find the tents blighted by condensation? How is it condensation and rise from a platform to soak the inside of the tent? That doesn't quite gel. :?

Personal experience: I have camped in several places, albeit not on recycled plastic platforms, nor wood, but in frosty, dirty pads, wet grass and even shingles. Condensation from overnight is normal and expected; easily fixed: aired the tent on rising in the morning and left vents open and come back to a dry and welcoming tent in the afternoon, ready for the next night of minus 6 degrees.

Condensation inside the sleeping bag is easily dealt with; open the footbox zipper half way and wear sleeping socks (on one of my bone-chilling minus 6 degree walks back in Victoria, I wore MD Bearfoot booties to bed — toasty warm and dry). Wearing a plastic bag close to the skin while sleeping is begging for a fungal infection.

Re: Plastic tent platforms are madness

PostPosted: Mon 17 May, 2021 3:19 pm
by north-north-west
The condensation is on the outside of the bag, not the inside. No amount of wool/down insulation stops the damp end problem. The bags do. Feet get aired out before they go on and before putting on walking gear the next day. If it starts to cause problems, I'll deal with them if/when they arise.

Kind of hard to air a tent out all day when you're carrying said tent during the day in order to reach your next campsite.

Re: Plastic tent platforms are madness

PostPosted: Fri 21 May, 2021 9:19 pm
by clarence
icefest wrote:
clarence wrote:why the foot of your sleeping bag gets wet on a cold night in a tent

Isn't that just because it's touching the tent wall?

At least, it only happens to me when my bag does. :/


There are several factors at play, and they would all vary slightly in different situations. A few factors:

The area around the feet (on average) is likely to be the coldest part of the tent at ground level
Ditto for air movement
If feet sweat more (and/or are wet, as another poster suggest) this would increase vapour load through sleeping bag to the outer layers
If feet are colder (than other parts of the body), then there is relatively less heat passing out through the sleeping bag to warm the outer layers

Interestingly, in theory wearing more layers on feet could change the situation by making the outer layer of the sleeping bag even colder (meaning more condensation as there would be less heat drive).

Clarence

Re: Plastic tent platforms are madness

PostPosted: Wed 02 Jun, 2021 11:29 am
by legend
Just to throw another mix into the ring.
What happens when you pitch your tent on the ground?
It will be generally damp (dig down a centimetre or so and you'll find moisture).
Any vegetation will be expell moisture day and night (hence cover the vestibule floor with some form of groundsheet).
If you have a completely sealed space with no openings then the evaporated moisture will form on the waterproof material.
Btw, if you have ever slept under a tent fly in cold, still weather (desert conditions excluded), you will find the fly covered in condensation. Again, the fly will be trap the moisture expelled by the vegetation. The underside will be dripping wet in the morning.