Det a good night's sleep - self-inflating mats
In fact, the old camping saying was one third insulation above and two thirds beneath for a good night’s sleep – your sleeping bag providing the upper insulation and a mattress or mat providing the bottom insulation.
While we look at sleeping bags here it has long been recognised that what goes underneath is a major factor to sleep comfort and your enjoyment of the camping experience for it insulates you from the hard, cold ground. However, the days when campers slept on blankets, or an unsophisticated airbed, are long gone. Modern materials have allowed us to move on to mats and mattresses that offer home-like comfort levels.
At their simplest, insulation is offered by closed-cell mats that trap insulating bubbles of air between you and the ground. But, while they conserve body heat, they do not offer the best padding from bumps in the ground and stones. The thicker air bed certainly provides a comfortable base on which to rest but the internal mass of air can sap body heat unless you add extra thermal insulation between you and the ground.
SOLVING THE PROBLEM
The invention of the self-inflating mat (or SIM as they are popularly known) solved these problems. The SIM comprises of an ‘airbed’ style outer filled with open cell foam. This starts to expand and draw in air to self-inflate as soon as you open the valve. Once the mat is fully inflated you blow in a little more air to adjust firmness to suit personal taste before closing off the valve. If the mat is too firm, just let a little air out. The aim is to have something that supports rather than feel like a paving slab.
The foam has a ‘memory’ and this is effected if compressed for any length of time. When you first use a SIM, or use it after being stored for long periods in its deflated state, you might have to blow in air to help it regain its shape. But, it is always worth minimising the amount of air you blow into a mat – the moisture introduced can cause the growth of mould that can adversely affect the foam.
This neatly leads us on to storage and use. It is good practice to store a SIM in its inflated state with the valve open. This ensures the foam maintains its memory and any moisture trapped inside evaporates away. Many campers store SIMs behind furniture, like wardrobes.
When in use, it is good practice to open the valve during the day. Not only does this help any moisture to evaporate off but any changes in air pressure due to daily temperature fluctuations will not damage the SIM.
SIMs can be purchased in various thicknesses to offer numerous insulation and comfort levels. If storage and transportation space is at a premium, it is worth remembering that, while so comfortable, the weight and bulk of a SIM increase the thicker it gets. And, the thicker it gets the harder it is to pack away, However, a simple procedure ensures stress is kept to a minimum.
When you roll up your SIM you open the valve to let air out. Yet, as soon as you do that, the foam wants to expand and suck air in. This makes it very difficult to roll the mat away unless…
First, open the valve. Next, fold the mat into thirds towards the valve, pressing your body weight down to remove air each time you fold it over. Close the valve to prevent air from being drawn in.
Unfold the mat and start to roll towards the valve. Open the valve once you meet air resistance and continue to roll up the SIM to remove excess air. Close the valve.
If there is still too much air left in the SIM, unroll and tightly roll up again until you meet air resistance. Open the valve and continue to roll until all air is expelled. This will be far easier…
SIM maintenance is simple. Clean, dry and store, where possible, unrolled with the valve open. Any punctures can be treated like a bicycle tyre.
You’ll be pleased to hear that Easy Camp offers a choice of single and double SIMs in different thicknesses to suit needs, along with airbeds and EVA mats. Check out the range here