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Bivy inside a Mid Shelter or Ground Sheet?
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Tony Wong
(Valshar) - MLife

Locale: San Francisco Bay Area
Bivy inside a Mid Shelter or Ground Sheet? on 08/27/2013 12:16:44 MDT Print View

I've been a Tarp and Bivy guy for a number of years and I am considering using a MLD solo mid in silnylon for shoulder seasons where there are very rainy conditions.

Do people using mids in rain also use a bivy or do they just go with a ground sheet?

What recommendations would people have for a light weight and waterproof ground sheet to use inside a mid?

Also, any particular techniques suggested when using a ground sheet in rainy weather to prevent water from rolling inside the mid and on top of the ground sheet and getting gear wet?



(RobertM2S) - M

Locale: Lake Tahoe
Zpacks ground sheets on 08/27/2013 13:09:14 MDT Print View

These have stand-up edges, forming a little bathtub. They're sold sepatately.

Brian Johns

Locale: NorCal
Oookworks on 08/27/2013 14:57:35 MDT Print View

I have an Oookworks solo floor of chikara (sp?) nylon with 10 cm. bathtub sides that stay up at all times. Simple to clip to the mid stakes, and at 3.8 oz., ill never use polycro again. I also have a bivy (Borah) I use for colder nights but I have never found I needed anything for rain. For reference, I am using a duomid.

Note: Last month ookworks had several similar to my floor made up ready for no wait sale on the site. I would look them up, I've been very happy. For more money, Zpacks has you covered too.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Bivy inside a Mid Shelter or Ground Sheet? on 08/27/2013 15:47:20 MDT Print View

I use bivy inside mid.

If it's windy and rainy, stuff will sometimes blow in so bivy is good

If the weather is good then I can just use bivy which is good against dew and have mid in reserve if it starts raining

Avoid camping in a stream channel or pond and you don't need raised edges.

The raised edges of bathtub floor also keep the water in. If any water gets on it, you want it to just run off. Just keep it well away from edges so rain splash doesn't get on it.

I can think of a couple times when water got onto a bathtub floor, didn't run off, and got me wet.

I can also think of a couple times I camped in what became a shallow pool, but I don't think a bathtub floor would be waterproof enough to keep it out. Eventually I'll learn not to do this.

Arn Aarreberg
(aarrebea) - M

Locale: Northern Bay Area, CA
2 for zpacks on 08/27/2013 15:48:40 MDT Print View

The zpacks groundsheet should work really well in the solomid. I also have a borah bivy that has worked great under my solomid. Either would do the job but the bivy would add more weight and some warmth. I think either way, I would want some protection up the sides of my sleeping bag.

I spent a very rainy night at Pt. Reyes last winter under my solomid with just a sheet of polycryo. I got splash around the edges and my bag did get wet. I got wet enough where I would not want to spend another rainy night under that shelter without a bivy or bathtub floor. Just for reference, I am also 6'4, 200 lbs. So I am pushing the limits of being comfortable in this shelter.

Edited by aarrebea on 08/27/2013 15:49:55 MDT.

Hiking Malto
(gg-man) - F
Seasonal on 08/27/2013 16:21:41 MDT Print View

Bivy when cold, bug net with bathtub floor when not cold.

Mike M
(mtwarden) - MLife

Locale: Montana
depends on 08/27/2013 19:30:36 MDT Print View

if it's a solo mid- I prefer a bivy for possible splash, a larger mid w/ more coverage I'm comfortable w/ just a ground cloth (or an inner if there are bugs to contend w/)

I've had good luck w/ Tyvek for ground cloth- stuff is amazingly tough and no overly slippery (albeit it's heavier than polycro); I grommet the corners and use a small diameter shock cord to secure the corners to the mid

Tony Wong
(Valshar) - MLife

Locale: San Francisco Bay Area
Re: Bivy inside a Mid Shelter or Ground Sheet? on 08/28/2013 20:32:35 MDT Print View

I appreciate everyone's feedback.

I have taken a look at zpack's offerings and polycro sheets from Gossamer Gear.

Arn: Especially appreciate your sharing your experience from Pt Reyes, which is not too far away from me.

My use of a mid would be for when I expect days of rain over long periods of time.

Mid would be nice vs. a tarp and bivy so I can sit up.

Still sounds like a bivy for water protection is a good idea even with a mid.

Love you guys and appreciate any experiences you have had.

Nice idea bout taping the tyvek to make a bathtub floor.


Dean F.
(acrosome) - MLife

Locale: Back in the Front Range
Bivy on 08/29/2013 06:22:16 MDT Print View

A couple of years ago I decided that a pyramid tarp and a light bivy is the most versatile shelter solution, and it's what i use in my DuoMid With the bivy you don't need a groundsheet. You can find 5oz or 6oz bivies that are bug-proof for bug season- lighter than an innernet.

Dave -
(FamilyGuy) - F

Locale: Up there
Re: Bivy inside a Mid Shelter or Ground Sheet? on 08/29/2013 11:05:21 MDT Print View

With my DuoMid, I used a bivy. However, I also used a groundsheet when I was expecting truly wet conditions because the condensation from the wet ground can be significant. My bivy was only water resistant, however.

Stephen Barber
(grampa) - MLife

Locale: SoCal
Bivy inside a Mid on 08/29/2013 12:21:55 MDT Print View

I use a MLD superlight bivy with the bug head covering in my Duo and Cricket. (If I expect really bad bug situation, I'll use an inner net). The bivy protects from wet ground, splash, wind under the edges of the shaped tarp, and bugs. What more could I ask?

Dave's use of a ground sheet under the bivy when expecting really wet conditions makes sense. It's not a situation I encounter much in the southern Sierras and transverse ranges.

Tony Wong
(Valshar) - MLife

Locale: San Francisco Bay Area
Re: Bivy inside a Mid on 08/30/2013 13:38:12 MDT Print View


The "problem" is that I using a MLD eVent Soul Bivy, which I love and has been holding up great since 2008, but it is 13 oz.

Add a 15 oz MLD Solo Mid, I am pushing into the weight of a Tarptent Notch.

If I had your bivy, I would come out great with that combo, but I am not willing to give up my current bivy....too much invested into it in terms of money and it is just great.

It does have a silnylon 2.0 floor, which is pretty waterproof, but might wet out after long periods of time on really damp ground.

Learning lots here about how considering "one" change can effect the whole balance of gear that I am using.

My setup now if great for the Sierras, but if I wanted to head to the Pacific North West, I have to consider having more protection from rain.

I like the flexibility of just using a bivy to sleep out under the stars and in small spots that might not allow a tent/mid/tarp and then using the Mid with the bivy when things get bad, but I do have to question if a tarptent would be better.

I do have a Contrail, which I have not used in years, since going to the tarp and bivy.....

Just mental games to think about between trips.

Again, appreciate the advice from everyone.

Ultimately, in very rainy situtations, sounds like a mid, bivy, and groundsheet might be in order....but better to carry some extra weight vs. being miserably wet.