Prep for winter Cheapskate advice

[Moondog55]

It never being too early to start preparing for white season I thought I'd mention something again and early.
Lately I have seen a lot of the older style ThermaRest small mats for sale and at bargain basement prices [ I paid $5- each at the Salvos last year] and with comfort mats getting thicker and thicker we are winding up with less room inside our tents.
My experience has been that in white season putting the insulation under the tent floor works better; so to that end if you are thinking about a winter trip perhaps you should be looking for cheap SI mats in the original 25mm thickness.
Three of the small mats laid across the tent will cover most bushwalking winter tents.
Naturally any insulation under the floor works, CCF works as well but is more bulky and also naturally thicker is better.

[Aardvark]

My experience has been that in white season putting the insulation under the tent floor works better;

Of course insulation works by trapping air and your body heat warming that air.
Don't you think you should elaborate on the science of 'putting the mat UNDER the tent floor'.
I'm not buying it yet.

[Moondog55]

Conduction blocking

[Neo]

Makes sense to me, having a layer under the tent then inside sleep on your preferred mat. Although I would guess ccf would still be a better insulator than the foam inside thin self inflating mats which is kind of just sponge.

[Moondog55]

It really depends on how hard you inflate the ThermaRest. In this case it's not for comfort so the harder the better.
The ideal would be 150mm of styrene foam but that's not feasible unless in Antarctica.
I've used almost everything from thin flooring underlay to cheap CCF pads from Clark Rubber and the SI mats are probably the best cheap option

[Warin]

My experience has been that in white season putting the insulation under the tent floor works better;

Of course insulation works by trapping air and your body heat warming that air.
Don't you think you should elaborate on the science of 'putting the mat UNDER the tent floor'.
I'm not buying it yet.

I put a CCF mat under the tent floor to protect the tent floor and my inflating mat .. from any spiky things I may have missed. Yes it also adds to the insulation, but under or over the tent floor would have little effect, unless water is flowing under the tent floor.

Insulation?
Convection - by circulating air/water .. any gas or fluid really. Any non permeable barrier will stop it.
Conduction - through a material ... the denser the material usually has better conduction. A vacuum works well at stopping it.
Radiation - think of the sun shining on you. A mirror will stop it ..

Good insulation stops all 3 of the above.