Everything You Need to Know about Bouldering Mat Foam

By Pete Dollman

We see foam as the most important part of your bouldering pad. Sure it may have a super funky design and all the features, but if the foam’s no good then you may as well not have it.

What is the Best Foam for Bouldering Pads?

In theory the ideal foam for bouldering pads is a thick, soft, high density natural PU foam (think gymnastic crash pads/mats at climbing walls) which will absorb energy slowly for a softer fall.

Unfortunately this foam is incredibly heavy, so we have to make a compromise. It doesn’t matter how good your pad is if you can't manage to carry it to the problems!

You want your foam to cushion your fall and cover lots of your landing zone all the while being portable and durable.


8cm Light and portable taco style bouldering pad, ideal for whipping round your local circuit


11cm Taco style main bouldering mat for a portable uninterupted landing zone.

How to Identify Good Quality Foam

Pay close attention to the foam density of your bouldering mat. Not all foam is created equal when it comes to repeatedly landing on it, with some types of foam prone to softening much quicker than others.

Foam density tells us how durable and supportive a PU foam is. It measures mass per unit volume of foam.

Through flex fatigue testing, several studies have indicated that the higher the polymer density of the foam, the slower the rate of degradation and softening. A soft pad isn’t so supportive.

When to be Wary

Very often, foam used for portable bouldering mats contains additives which artificially harden it for its density. The result is a lighter pad that still feels hard. Sounds ace, but this comes at a cost to durability because although the foam + additives is denser, the polymer density isn’t any higher and it’s the polymer density that counts.

This is also why the foam in your pads start to degrade and become soft after a couple of years of use, whereas the foam in your mattress (the same foam, fact fans) will last ten years or more.

Good quality high density foam may be heavier and costlier, but it will last longer. Light hard foam is cheaper but will soften quickly!

So perhaps the weight of a mat is a better indication of its quality than its hardness?


11cm Hinge style full bouldering mat for regular rock wranglers


15cm Hinge style oversized bouldering pad for high-ball problems

What Types of Bouldering Mat Foam are there?

There are two main types of bouldering mat foam, open cell and closed cell.

The ideal foam should be soft on small falls, but very resistant to bottoming out when you hit it from height. To make this possible in a portable, durable crash pad, we make our pads from using layers of both open and closed cell foam.

Open Cell Foam

Open cell foam absorbs the impact of your falls. It’s a softer, less dense foam that makes up the core or bottom of your pad. It works because it’s made of irregularly shaped cells that are linked together and compress when you fall on them.

Closed Cell Foam

Closed cell foam distributes your weight across your landing surface so you don’t ‘bottom out’ (compress the foam so much that you hit the ground through your pad), and is used for the top layer of your pad.

It works because it’s made from rigid, uniform cells that don’t compress much when you fall on them.

Two layers of foam is pretty standard, with a top layer of closed cell foam and a base of open cell. Pads designed for higher impact falls though often use 3 layers of foam (closed, open, closed) to give a second layer of protection when the risk of bottoming out is even higher.

How to Store Your Bouldering Mat?

Make your foam last longer by storing both taco and hinge style crash pads open and flat. Easier said than done when you're already fighting for space at home, but when the result is even more years of bouldering abuse it's well worth it.

Store Your Mat Clean and Dry

Make sure your mat is clean before storing. This keeps your mat in good shape and stops it from ponging out the house.

To clean your boulder pad, wipe the shell clean with a damp rag or scrub it with a soft brush. Use a soap-based detergent to shift all the grit engrained along the stitching line without damaging the fabric.

Wet mats end up smelly and mouldy, so airdry your mat before storing. To dry damp foam, unzip the shell to allow the air to circulate.

Be wary of heating your mat to dry it (for example, with a radiator/hair dryer) as the fluctuating temperatures could cause the foam to degrade. Removing the foam is best avoided: it’s super durable inside its shell, but once removed it becomes very delicate. Much like a tortoise really.

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