Quilt/sleeping bag cover - include the mat or not?

[Tortoise]

Some people will have experience with ready made covers, so I thought I'd post here.

I'm hopefully going to make a Tyvek quilt/sleeping bag cover. (Thanks, Simon. Most excellent service!) Assuming I can get my head around possible design tweekage, a new needle & foot for my machine etc, my question is this:

What are the advantages/disadvantages of making the cover big enough only for me and my quilt, rather than including the mat (Xtherm), as in a normal bivvy?

I'm a side sleeper who tends to curl up. My purpose for making the cover is:

1. To have a water resistant cover to avoid dampness on my non-waterproof quilt from condensation in my tent.

2. To increase the warmth of my light weight sleeping system.

I have some elastic linking the side tabs on my quilt. When it's cold, I shorten the elastic, and it goes under me, on top of the mat. When cold isn't an issue, I lengthen it and it goes under the mat, which makes rolling over (of which I do a lot) easier.

My thoughts so far on making it only big enough to include me and the quilt

Pros:
1. It will be smaller and lighter, saving the weight I’m keen to save.
2. I’ll still be able to curl up – my legs, the quilt and cover will all move together, on top of the mat.

Cons :
1. I sometimes stay in a hut, where it would be good to have the cover protect the underside of my mat.

I’m sure there are some other reasons, as this is the only set up I've seen in photos. Sure, some people want to use it as a bivvy, under a tarp. But are there other reasons I haven’t thought of? I’m thinking there would be more air to warm up if the cover goes around my mat, but maybe the Xtherm means there’s not as much cold air around me anyway.

Thanks for any thoughts.

[Bluegum Mic]

To negate the hut issue why not make it as your thinking and then simply carry a rectangular shaped extra piece of tyvek for the times you know you'll be in a hut and it can be like a ground sheet for your mattress

[Supertramp]

Call me crazy, but Tyvek isn't waster resistant, silnylon would be a better option for the water resistant side of things.

I do have a bit of a head cold & may have missed the point completely.

[Strider]

I thought Tyvek was supposed to be taped, not sewn?

[Tortoise]

Call me crazy, but Tyvek isn't waster resistant, silnylon would be a better option for the water resistant side of things. I do have a bit of a head cold & may have missed the point completely.

From
http://www.terrarosagear.com/materialsconstruction.htm
where you can buy sleeping bag covers already made up:

After a year of rigorously testing Tyvek 1443R, I have found it to be fully functional for lightweight tarps. Although not waterproof, it is weatherproof and more than adequate for repelling even the most heavy precipitation. Tyvek is a non-woven material and has slightly less tensile strength compared to sil-nylon. It gains a slight amount of weight when wet but dries exceptionally quickly

and

The quilt/bag cover is designed to be the perfect addition to the tarp shelter protecting from poor weather "splash up" as well as heat robbing wind.
Its construction from TYVEK1443r allows for great breathability and water resistance.
The wind blocking properties also improve the warmth rating of ones quilt or bag.
The deluxe version features a Sil Nylon base if you would like to leave the ground sheet at home.

I believe more than one member on this site has been very happy with theirs, so that's enough for me. SilNylon doesn't breathe does it? I think i'd be swimming in condensation inside the bag.

I thought Tyvek was supposed to be taped, not sewn?

Google 'sew Tyvek', and you'll gets lots of examples. From what I understand, it can be taped or sewn. Pretty sure Evan (Terra Rosa Gear) sews his.

Appreciate your thoughts - keep them coming

[Tortoise]

The hammockforums.net explain a bit more in 'The definitive Tyvek Article Part 2'
https://www.hammockforums.net/forum/showthread.php?524-The-Definitive-Tyvek-Article-Part-2

Can Tyvek be used as a vapor barrier?
No. Tyvek is not a vapor barrier. Tyvek blocks wind and water and still remains breathable and allows water vapor to pass through the material, which makes it good to use as a weather shield. Unlike fabrics that have been coated with a waterproofing agent, Tyvek’s water resistance is due to the construction of the material. Tyvek has tiny holes that are too small to let bulk water and wind pass but are large enough to allow water vapor to escape. <1>

[simonm]

I thought Tyvek was supposed to be taped, not sewn?

It's common to sew the soft structure Tyvek (14), though you want to keep the stitch length quite long, and the smallest needle compatible with your thread.
For a project like a quilt cover there should be very little stress on the seams but like sewing Cuben I would be inclined to sew through multiple layers at any potential stress points.

[Ellobuddha]

Ive got one of Evans (Terrarosa) bag covers. I got mine made big enough for my quilt and pad. Might as well protect both for the small weight penalty in my opinion. Im very happy with it. I got it quite long as well so the whole mat and quilt can be completely covered over to protect from condensation or rain etc trying to get under the edges of my mid. Works very well

[Tortoise]

Ive got one of Evans (Terrarosa) bag covers. I got mine made big enough for my quilt and pad. Might as well protect both for the small weight penalty in my opinion. Im very happy with it. I got it quite long as well so the whole mat and quilt can be completely covered over to protect from condensation or rain etc trying to get under the edges of my mid. Works very well

Great to hear your perspective. Out of interest, is yours taped or sewn or both?

[Ellobuddha]

I'll have to check tomorrow but pretty sure its just sewn. It really does a good job of keeping that spray off your bag. Also stops any drafts getting in through edge of quilt, providing extra warmth. Its further great at stopping foot of bag laying against wall of mid, which can be an issue for taller people, especially in single skin mid with wall condensation.

Its got a large top opening so you can have it right up head height and it vents all your warm air out. Ive used it in some really damp cool nights prior to winter up Kozi area and was very impressed.

Will double check on the stitching. Did have a photo of it all set up but may have deleted it. Will check that as well.

JUST CONFIRMING THIS IS THE TYVEK 1443 - not the standard housewrap variety.

[Ellobuddha]

Quilt and mat

All tucked away in Terrarosa cover

[Tortoise]

I'll have to check tomorrow but pretty sure its just sewn. It really does a good job of keeping that spray off your bag. Also stops any drafts getting in through edge of quilt, providing extra warmth. Its further great at stopping foot of bag laying against wall of mid, which can be an issue for taller people, especially in single skin mid with wall condensation.

Its got a large top opening so you can have it right up head height and it vents all your warm air out. Ive used it in some really damp cool nights prior to winter up Kozi area and was very impressed.

Will double check on the stitching. Did have a photo of it all set up but may have deleted it. Will check that as well.

Thanks, Ellobuddha. Sounds exactly what I'm after. While I'm not *cough* exactly tall, I have the same foot problem as I tend to sleep halfway down the Akto for oodles of headroom... I'd also be happier using my mesh-only inner light weight 3 person tent when I need to share with a friend. Even in a 'snow bag' I wasn't keen on the breeze.
Thanks for the pics, too. As an aside, I can't quite work out if you put the ?tape ?elastic under you or under the mat.

[Ellobuddha]

They are the mat tapes going fully around the mat. The quilt is then clipped to the tabs on the tapes just in an inch or two on top of the mat. This tucks the quilt in around me a little more. I haven't used the elastic ones yet as alway have it attached to the mat as it lets me move around more.

On the right side of the quilt you can see where the tab on the quilt is attached to the mat tapes. Am I making sense?

So basically, there is a circular tape all the way around your mat, which you cinch up to stay in position. There are two tabs on this tape which clip onto the edge of the quilt itself to hold it in position. Better description????

[Tortoise]

Ah, I get it now. Looks like an excellent system. If you get time, could you please do a close-up pic of the tape/clips? I've just used narrow elastic that works ok, but yours looks ideal.

Thanks a lot for your info.

[Ellobuddha]

Will do. Its the standard system from Enlightened Equipment quilts. It may be on their website. They have just come out with a newer version. See the EE quilt thread. I think Katabatic Gear run similar style but with cord and clips instead of tape and clips.

[Tortoise]

Will do. Its the standard system from Enlightened Equipment quilts. It may be on their website.

Yep, it is. Thank you!

[Scottyk]

I'll have to check tomorrow but pretty sure its just sewn. It really does a good job of keeping that spray off your bag. Also stops any drafts getting in through edge of quilt, providing extra warmth. Its further great at stopping foot of bag laying against wall of mid, which can be an issue for taller people, especially in single skin mid with wall condensation.

Its got a large top opening so you can have it right up head height and it vents all your warm air out. Ive used it in some really damp cool nights prior to winter up Kozi area and was very impressed.

Will double check on the stitching. Did have a photo of it all set up but may have deleted it. Will check that as well.

JUST CONFIRMING THIS IS THE TYVEK 1443 - not the standard housewrap variety.

Don't you find it getting wet under the tyvek as it stops the moisture coming out of your bag from floating away?
I have a SOl escape bivy which I have used as just the kind of thing you have here and I found it just held the moisture against the outside of the bag and so led to a wet outer sleeping bag, it was a few very cold nights The SOL product looks to be a tyvek type fabric and claims to be breathable.
I suppose I could see the purpose if your tent dripped on you but I have spent some nights in some very bad condensation situations and have never had a tent drip on me, I would buy a new tent if it did that. I also think that what a lot of people think is there sleeping bag rubbing against the end of the tent and getting wet is often moisture coming out of the foot box from the occupant of the bag.

[Tortoise]

Don't you find it getting wet under the tyvek as it stops the moisture coming out of your bag from floating away?
I have a SOl escape bivy which I have used as just the kind of thing you have here and I found it just held the moisture against the outside of the bag and so led to a wet outer sleeping bag, it was a few very cold nights The SOL product looks to be a tyvek type fabric and claims to be breathable.
I suppose I could see the purpose if your tent dripped on you but I have spent some nights in some very bad condensation situations and have never had a tent drip on me, I would buy a new tent if it did that. I also think that what a lot of people think is there sleeping bag rubbing against the end of the tent and getting wet is often moisture coming out of the foot box from the occupant of the bag.

Interesting thoughts, Scotty. I've tried the SOL escape bivvy too, and yes, my quilt was damp. It must be a bit different though, as it's not intended to be used many times (I came across that somewhere in my reading). And of course there are different degrees of breathability. I wonder if the reflective lining in the SOL bivvy reduces its breathability.

On the foot box dampness - you may have a point, but why would it just be at the foot, where my body tends to be the coolest? I also have woken up on occasions with my bag against the wall, having tossed and turned a little too vigorously.

[Ellobuddha]

Ive found that it breathes quite well. The large opening allows heat from my breath etc to escape. Ive never had the bag wet between the two layers. I still get a little dampness at the footbox but as you said, i think thats from heat escaping the bottom of my EE REVELATION. It is minor and dries in a matter of minutes. Same as the top of my quilt from my breath. Definitely no major dampness across bag.

My main reason for it is for rain/ moisture which sneaks into my duomid and also from wall contact. I don't need or use it in my tent (Jannu)

[Scottyk]

Don't you find it getting wet under the tyvek as it stops the moisture coming out of your bag from floating away?
I have a SOl escape bivy which I have used as just the kind of thing you have here and I found it just held the moisture against the outside of the bag and so led to a wet outer sleeping bag, it was a few very cold nights The SOL product looks to be a tyvek type fabric and claims to be breathable.
I suppose I could see the purpose if your tent dripped on you but I have spent some nights in some very bad condensation situations and have never had a tent drip on me, I would buy a new tent if it did that. I also think that what a lot of people think is there sleeping bag rubbing against the end of the tent and getting wet is often moisture coming out of the foot box from the occupant of the bag.

Interesting thoughts, Scotty. I've tried the SOL escape bivvy too, and yes, my quilt was damp. It must be a bit different though, as it's not intended to be used many times (I came across that somewhere in my reading). And of course there are different degrees of breathability. I wonder if the reflective lining in the SOL bivvy reduces its breathability.

On the foot box dampness - you may have a point, but why would it just be at the foot, where my body tends to be the coolest? I also have woken up on occasions with my bag against the wall, having tossed and turned a little too vigorously.

I am not sure why but the most moisture seems to gather in the foot box area, maybe its because it gets the least fresh air circulation? The top of the bag will get a bit of air as you move around.
I have had a wet bag on the sides as well when sleeping 2 up in a small tent and that seems to come from the bathtub floor getting wet from contestation and then you wipe it off with your bag.
Back to the original topic, I tried to have the SOL escape bivy around the mat as well and it compressed the down and made it cold. Much better with the mat out of the set up. High loft down takes so little to compress you down want anything pulling down on it

[Tortoise]

Don't you find it getting wet under the tyvek as it stops the moisture coming out of your bag from floating away?
I have a SOl escape bivy which I have used as just the kind of thing you have here and I found it just held the moisture against the outside of the bag and so led to a wet outer sleeping bag, it was a few very cold nights The SOL product looks to be a tyvek type fabric and claims to be breathable.
I suppose I could see the purpose if your tent dripped on you but I have spent some nights in some very bad condensation situations and have never had a tent drip on me, I would buy a new tent if it did that. I also think that what a lot of people think is there sleeping bag rubbing against the end of the tent and getting wet is often moisture coming out of the foot box from the occupant of the bag.

Interesting thoughts, Scotty. I've tried the SOL escape bivvy too, and yes, my quilt was damp. It must be a bit different though, as it's not intended to be used many times (I came across that somewhere in my reading). And of course there are different degrees of breathability. I wonder if the reflective lining in the SOL bivvy reduces its breathability.

On the foot box dampness - you may have a point, but why would it just be at the foot, where my body tends to be the coolest? I also have woken up on occasions with my bag against the wall, having tossed and turned a little too vigorously.

Well, after some excellent experiences with my quilt cover, I've now had a less positive one - camped near a lake on a clear night. I used it because with a forecast of -5C, and having it close to that in the late arvo, I wanted to prevent any cold air creeping in while I tossed and turned under my winter quilt, and to have another insulating layer. And to keep the quilt dry from anticipated ice in the inner - which I did encounter, and was happily cosy during the night.

I left the foot of the quilt cover open, and didn't have it over my head. In the morning the quilt felt drenched. Fortunately it's water-resistant down, and i was only out for a couple of nights. I was surprised that it didn't feel so wet the next night when I pulled it out of its bag. I was also in a hut with a heater, so not a big deal this time. But it had me discouraged about using the cover to boost my winter sleeping system.

[Scottyk]

Cheers for the update
I reckon if your hot in bed it makes it worse too, more moisture coming off your body.
It varies so much with the conditions its hard to know whats the best answer. I have gone for synthetic quilt because the moisture doesn't better much.

[Tortoise]

Hey Scotty,

I did toy with the synthetic option for that benefit - but went for the lighter less bulky option in view of my general effort to reduce pack weight. Very glad I went for the treated down though - for the extra 20gm or whatever it was.

I have realised that I could have left the top of the fly zip/vent open more, which should help a bit next time.

Reckon you're right re being hot - though that's never a problem I have these days! I'm just trying to keep warm enough. I confess to being a 2 doona user at home. Wonder if I should work on acclimatising to lower temperatures at home...