How to Choose a sleeping Mat

Sleeping mats fall into 3 categories. Self inflating mats, Non self inflating mats and Closed cell foam mats. Before we look at each type, a few words about what a mat does for you. The most important thing the mat does is keep you warm. Tests have shown that you loose 3 times as much heat to the ground (conduction) as you do to the air (convection). Also your sleeping bag is compressed under you and is less effective that when it is properly lofted, so it really is your mat that keeps you warm. If you are cold at night, buy a better mat not a bigger, bulkier sleeping bag, it will be cheaper too. The second thing a mat does is make you comfortable enough to sleep. It’s no good being warm and having a stone in your shoulder blade. The different mats offer different firmness much like different styles of sprung mattresses. There is no right or wrong here, but if you like a firm bed, you will probably prefer a firm sleeping mat. Right, let’s look at the 3 types of mat.

Self inflating mats are a layer of foam sandwiched inside an air tight shell with a valve. When the valve is opened the foam expands and sucks air into the mat. Once the foam has fully expanded the valve is closed and the mat is ready for use. Different models vary how much foam and air is inside and this affects how much insulation and comfort the mat offers the user, against how much the mat weighs and how small it packs.
To pack the mat, open the valve and roll up the mat to squeeze out all the air, then close the valve again and the mat will stay rolled up.
The most well known of brands for this type of mat is Thermarest, but their are many other makes. Self inflating mats tend to be thinner and firmer than non self inflating mats with typical thichnesses from 2.5 to 5cm. R values* 2.3 – 4

Non self inflating mats, comprise the same airtight outer layer and valve as self infalting mats but do not have the layer of foam. Since it is the foam that sucks the air into self inflating mats, these mats must be inflated by the user. They can have insulation inside as well as air or just air. An air only mat has low insulation and is really only for summer use, but down or synthetic filled mats have excellent insulation. Non self inflating mats also tend to be thicker and have more air inside than self inflating mats, typical thichnesses of 7-10cm, which gives a softer feel. Non self inflating mats are packed in the same way as self inflating mats, by opening the valve and rolling the air out but since there is no foam to compress they tend to be lighter and pack smaller than self inflating mats. R values* 0.6 – 8

Closed cell foam mats have no outer airtight skin, they are a simple piece of foam that does not compress. You just roll them out and roll them back up again. They are ‘closed cell’ because they will not absorb any water, rather than ‘open cell’ which is more like a sponge. These mats are much cheaper and maintenance free but offer minimal comfort and insulation. Once you have used one of the other two styles you will never be happy on a closed cell mat. R Values* 2.2 – 2.6

* R values are Warmth Resistance Values and offer a standardised value for comparing insulation properties of mats. The higher the number the more insulation the mat offers

The types of mat and their properties are summarized below. Click on the name of the series or mat to see more info.

Mat Type Filling Packability Insulation ( R value) Cost £ Firmness
Exped DownMat Series Non self inflating Air & Down Feathers Excellent 4.9 – 8 80-115 Soft – Medium
Exped Synmat Series Non self inflating Air & Synthetic insulation Excellent 4.5 – 6.2 80 – 95 Soft – Medium
Thermarest Prolite Series Self inflating Air & Foam Very Good 2.3 – 3.2 59 – 74 Firm
Thermarest Trek Series Self inflating Air & Foam Good 3.8 – 5 39 – 69 Firm
Thermarest Ridge Rest Closed cell None O.K. 2.6 20 Rock Hard
Thermarest Z Lite Closed cell None O.K. 2.2 24 Rock Hard
Exped Airmat Series Non self inflating Air Excellent 0.6 29 – 50 Soft – Medium

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