Self Inflating Airbed

[TheDon16]

Good afternoon
I’m in the process of buying a Vango California POP 5cm Double Sleeping Mat. Can you leave this in my pop up roof deflated or should I remove it when dropping the roof. I have seen conflicting advice.Many thanks. My van is. 2012 CAL SE T5

 

[Hawthorn37]

Firstly, welcome as this is your first post!

A couple of things - are you leaving in the VW foam mat in as well? I don’t know your van, but for us the available space in the roof is wafer thin, so I’d be checking this with care. Another aspect, it’s possible the self inflating mat could re-inflate even with the valves closed. I’d give the mat a good test. We have an Outdoor Revolution mat which certainly does inflate itself. There are some threads on this, with stitching pin holes being the likely reason.

We had thought of doing what you’re considering, but it’s not practical / safe for us. The cost of a roof repair isn’t worth the risk.

 

[WelshGas]

Firstly, welcome as this is your first post!

A couple of things - are you leaving in the VW foam mat in as well? I don’t know your van, but for us the available space in the roof is wafer thin, so I’d be checking this with care. Another aspect, it’s possible the self inflating mat could re-inflate even with the valves closed. I’d give the mat a good test. We have an Outdoor Revolution mat which certainly does inflate itself. There are some threads on this, with stitching pin holes being the likely reason.

We had thought of doing what you’re considering, but it’s not practical / safe for us. The cost of a roof repair isn’t worth the risk.

I'm sorry, but if a deflated mattress , with or without the VW foam mattress can fit within the closed roof space then it can only inflate to fill any void left. It cannot generate any more force than the atmospheric pressure within the roof space.
If rolled up and put in a storage bag it doesn't self inflate and rupture the bag.

 

[Hawthorn37]

Our mattress inflates to the state where, even with elastic straps in place, makes it near impossible to extract it from the oversize storage bag. I now use thin ropes to keep it from doing this. The expansion pressure of the mat clearly is greater than atmospheric pressure, or it wouldn’t inflate at all. It’s your own choice, I’m just saying that there’s no way I’m testing it.

 

[pchmlk]

Surely you close the valves when it’s deflated?

 

[JuanVecino2023]

Surely you close the valves when it’s deflated?

They still inflate with time. And change in temperature. Higher temperatures = higher pressure.

But as @WelshGas says, it can’t generate enough pressure to damage the roof by pushing against it.

 

[Hawthorn37]

Surely you close the valves when it’s deflated?

Yes. We even suck out as much air as possible with a little pump and then close the valves. Unless it’s tied up tight it will still fully inflate

 

[WelshGas]

Yes. We even suck out as much air as possible with a little pump and then close the valves. Unless it’s tied up tight it will still fully inflate

But it can only inflate to the size of the bag you use. The internal pressure will only be equivalent to atmospheric, so basically 0 psi comparing internal to external. That’s just physics.

 

[KAndyCalifornia]

We also have a self inflating mattress upstairs in our T6 Cali. It also has a slight leak that means it slowly self inflates once we have deflated it.

One thing to note is that the self inflating nature is driven by the internal structure of the mattress which I believe involves some memory foam which tries to revert to its initial size - when you squeeze or suck all the air out you are compressing the foam. So I think the pressure the mattress would exert on the roof is not to do with atmospheric pressure, but more the strength of the memory foam (or whatever it’s internal structure consists of).

We’ve had a bit of a debate here at KAndyCalifornia Towers as to how to deal with this. At the moment we suck all the air out of the mattress with a pump just before we close the roof. We then set a timer for 5 hours and then repeat the sucking. Sometimes we have to repeat that if we’re a bit late to the next site. We can do this without putting up the roof as we can just about get to the valves with it down.

When we first put the roof down, it is quite easy to get fingers and hand between the mattress and the roof, but certainly after 5 or 6 hours it gets pretty tight in there.

We take it out of the van and leave it inflated on a spare bed in the house between trips.

I suspect the likelihood of damage to the roof is not high if you don’t follow a regime like this, but like another commenter, I wouldn’t like to do too much experimenting to find out what the limits are. If someone would like to try, I’d be interested in the results.

BTW, some might ask why we keep persisting with the self inflating mattress. The memory foam does make it more comfortable than the standard mattress or an inflatable mattress. Ours is from Outdoor Revolution.

 

[Hawthorn37]

We also have a self inflating mattress upstairs in our T6 Cali. It also has a slight leak that means it slowly self inflates once we have deflated it.

One thing to note is that the self inflating nature is driven by the internal structure of the mattress which I believe involves some memory foam which tries to revert to its initial size - when you squeeze or suck all the air out you are compressing the foam. So I think the pressure the mattress would exert on the roof is not to do with atmospheric pressure, but more the strength of the memory foam (or whatever it’s internal structure consists of).

We’ve had a bit of a debate here at KAndyCalifornia Towers as to how to deal with this. At the moment we suck all the air out of the mattress with a pump just before we close the roof. We then set a timer for 5 hours and then repeat the sucking. Sometimes we have to repeat that if we’re a bit late to the next site. We can do this without putting up the roof as we can just about get to the valves with it down.

When we first put the roof down, it is quite easy to get fingers and hand between the mattress and the roof, but certainly after 5 or 6 hours it gets pretty tight in there.

We take it out of the van and leave it inflated on a spare bed in the house between trips.

I suspect the likelihood of damage to the roof is not high if you don’t follow a regime like this, but like another commenter, I wouldn’t like to do too much experimenting to find out what the limits are. If someone would like to try, I’d be interested in the results.

BTW, some might ask why we keep persisting with the self inflating mattress. The memory foam does make it more comfortable than the standard mattress or an inflatable mattress. Ours is from Outdoor Revolution.

Totally agree with your observations and conclusions. If, god forbid, there was damage to the roof for whatever reason, I’d imagine that if VW got to know a self inflating mattress was stored up there, there’d be a hasty rejection of a warranty claim! To us, it’s just not worth it. The clincher for us though is the effort (or noise) to deflate the mat up in the roof in the morning - just not worth the hassle, so we’re now only using the self inflating mat in the driveaway awning.

 

[Maidment_Ocean]

We also have a self inflating mattress upstairs in our T6 Cali. It also has a slight leak that means it slowly self inflates once we have deflated it.

One thing to note is that the self inflating nature is driven by the internal structure of the mattress which I believe involves some memory foam which tries to revert to its initial size - when you squeeze or suck all the air out you are compressing the foam. So I think the pressure the mattress would exert on the roof is not to do with atmospheric pressure, but more the strength of the memory foam (or whatever it’s internal structure consists of).

We’ve had a bit of a debate here at KAndyCalifornia Towers as to how to deal with this. At the moment we suck all the air out of the mattress with a pump just before we close the roof. We then set a timer for 5 hours and then repeat the sucking. Sometimes we have to repeat that if we’re a bit late to the next site. We can do this without putting up the roof as we can just about get to the valves with it down.

When we first put the roof down, it is quite easy to get fingers and hand between the mattress and the roof, but certainly after 5 or 6 hours it gets pretty tight in there.

We take it out of the van and leave it inflated on a spare bed in the house between trips.

I suspect the likelihood of damage to the roof is not high if you don’t follow a regime like this, but like another commenter, I wouldn’t like to do too much experimenting to find out what the limits are. If someone would like to try, I’d be interested in the results.

BTW, some might ask why we keep persisting with the self inflating mattress. The memory foam does make it more comfortable than the standard mattress or an inflatable mattress. Ours is from Outdoor Revolution.

I also have the outdoor revolution mattress, I suspect you have a slow leak.

I have had the mattress in my pop top for 6 months with no inflating between trips until the last 2 weeks. I noticed it had slightly inflated and also lost air in the night and needed a bit of inflation each night. I took it out fully inflated and with flowing water over the mattress noticed a tiny leak down the seam that is on 1 side of the mattress. Obviously this has the effect of sucking air in after deflation or letting air out after inflation. I have (hopefully) repaired today with some liquid rubber, and will test in next few days while away in the van.