An Explosive Guide To Paddle Board Psi

For the love of SUP, what is paddle board psi?

Psi is an abbreviation. It stands for pounds per square inch. Or, more accurately, pound-force per square inch.

Wikipedia describes psi as

the pressure resulting from a force of one pound-force applied to an area of one square inch.

With inflatable objects air or some other form of gas, is pumped into them. If you prevent that air from escaping as you continue pumping, the pressure inside the object increases. This increasingly dense air gets hotter and pushes, or exerts force, on the surface of the material the inflatable object is made from.

If that material is rigid and inflexible, the air becomes highly compressed e.g. aerosol canisters. If that material is stretchy and flexible like a balloon, it will expand as you fill it with air.

Up to a point.

Pumping up the Volume

Compressed air is always looking for a way out (or in). It wants to be equal with the outside/inside pressure.

Keep pumping in air, keep increasing that pressure and, at some point, it will find a weakness – either in the material or in the pump mechanism.

It will find or make an escape route.

Are all paddleboards inflatable?

No. Not all paddle boards are inflatable. Epoxy and foam stand up paddle boards are solid, valve-less, airless.

Inflatable paddle boards obviously are inflatable. You blow them up. And when fully inflated, they come in many different shapes, sizes, thickness and, therefore, volumes.

As we’ll see shortly, paddle board manufacturers have their own recommendations as to the ideal air pressure for their boards. Unless you want to void your warranty, it’s always best to adhere to your board’s psi guidelines as closely as you can.

Here’s ours below.

As you can see, Twobarefeet, our sup board suppliers (we are not affiliated to them btw), make their minimum and maximum recommended paddle board psi very clear.

So, what are some of the other recommended paddle board pressures out there?

What psi should a paddle board be?

We did some research, and this is a list of the psi figures that 10 of the major inflatable paddle board manufacturers / suppliers currently recommend for their own sup boards.

So, as you can see, recommended psi figures from some of the top inflatable paddle board manufacturers, differ quite a bit.

In some cases, the size and, therefore, volume of the paddle board matters. In others, the ambient temperature is taken into account.

But, if we were to extrapolate from all the research we did and answer the question “What psi should a paddle board be?”, it’s safe to say that:

• As a minimum, in temperatures less than 25 degrees, approx 15 psi is about right for most paddle boards.
• If you’re a heavier rider, or are looking to carry a little more weight, then inflation up to 18 psi should be okay.
• Greater than 18 psi is possible. But, unless you’re a pro SUP racer, or require the ultimate in rigidity and stiffness, there’s no practical benefit for the average paddle boarder. Plus, for it to be safe, you’ll require a specially designed and manufactured sup board from brands like irocker, Redpaddleco, Bluefin and Naish.

What will happen if my paddle board is under-inflated?

Paddle board performance is all about stiffness and rigidity.

If you’ve ever browsed or looked at buying an inflatable paddle board online, you might have seen shots of a paddle board propped up on blocks on dry land, with a confident looking paddleboarder standing in the middle of the board to advertise its strength. You might have even seen videos of inflatable paddle boards being run over by SUVs or trucks to demonstrate their strength.

Like this.

Poor thing!

What you rarely see, though, is an under inflated board getting tested.

Inflatable paddle boards assume their normal shape at about 3-4 psi (depending on paddle board size, of course). However, if you were to stop pumping and take to the water on your under inflated paddle board at 4 psi, you’d soon know about it. It would be like trying to stand up paddle board on a lilo. You’d become the filling of a paddle board sandwich.

Your sup board would turn into a SUPmarine.

The key is to find the right ratio of air pressure to rigidity for your weight, the conditions and your board. Not too much, not too little. You won’t damage your paddle board if it’s under inflated, but it certainly won’t work as well it’s designed to do.

So, when it comes to paddle boards, the stiffer the better, right?

Some manufacturers certainly think so.

Check out this YouTube video below from paddle board brand Naish.

Stiffness and rigidity can affect performance. It seems logical. Wallowing about in the water on a saggy banana is far less fun than skimming lightly above the waves on a solid, sleek marine missile.

So, for the pro SUP racers out there, maybe a 20-25 psi sup board does give them an advantage over a 15 psi board. Maybe for those using their SUPs for fishing, long distance touring or even for a little bit of SUP yoga, the added weight carrying capacity and lack of sag and flex might come in handy.

For the average day paddle boarder, however, it looks like there’s no benefit to getting a 25 psi inflatable sup, unless the board’s design also has stiffness and rigidity benefits at much lower pressure too.

Can you over inflate a stand up paddle board (SUP)?

Yes. You can over inflate a paddle board. Theoretically it’s even possible to burst one, if you use the wrong air pump and/or exceed the paddle board manufacturer’s psi recommendations. However, catastrophic over inflation is unlikely to be an issue unless you use an air compressor, rather than a manual or electric sup pump.

Pump up the volume. Pump it up. RIGHT UP! Wait…uh-oh!

I said 15 psi, not 50!!!

I defy anyone to burst their paddle board with a manual pump. Your arms will give out before your board will.

Electric pumps, although able to be overridden are, in most cases, regulated to 15-25 psi. Most electric sup pumps also have automatic cut outs when the pre-programmed psi figure is reached.

Aside: There are special valve attachments like this from Schrader, that can be attached to an air compressor like the ones you find at a petrol station to inflate your car tyres. There are also ones that are designed to safely blow off pressure when a specific psi is reached. We’ve no idea whether they work. All we know is that over-inflation as a result of using an air compressor will void any warranty you might have. And, from the little we’ve researched, air compressors are not much quicker than a manual or electric sup pump for reaching recommended psi.

What damage can over inflation do to your paddle board?

With severe over inflation, your paddle board seams may split, or the highly pressurised air will find a weak spot in the material and create a hole. Highly pressurised air can very quickly and explosively turn a small hole into a large tear causing potentially irreparable damage to your board.

If you over inflate your board by just a few psi above the manufacturer’s recommended guidelines, it’s unlikely to be a problem unless you leave or store your paddle board in a hot environment.

Heat causes air to expand and, therefore, air pressure (psi) to increase. That additional natural psi may cause an already slightly over-inflated sup board to go POP!

Are there any benefits to over-inflating your paddle board?

For the average stand-up paddle boarder, there are no real practical benefits to inflating a paddle board to greater than 15-18 psi. Although higher pressure can make a paddle board stiffer and more rigid, it can also damage your board.

There are some inflatable paddle boards on the market that can be inflated to very high pressures.

At first glance, these 23, 25 and 28 psi inflatable SUP boards might seem like they have a secret advantage over less pumped-up boards.

However, unless you plan on your isup supporting a weight of over 400lbs, or you need crazy amounts of stiffness and rigidity for something like performance SUP racing, a higher than normal psi is overkill.

The difference in stiffness and rigidity between a paddleboard inflated to 15 psi and one inflated to 25psi is apparently negligible.

So, for the vast majority of stand up inflatable paddle boarders, pumping a sup up to 18 plus psi will do nothing except, perhaps, give you a hernia.

So, no. Over inflation is likely to have little to no benefit for the average rider.

For the novice paddle boarder, 15-18 psi is perfectly adequate and should provide enough stability, rigidity & performance for almost any scenario.

Is there anything else that can affect paddle board psi?

Yes. Paddle board psi can be affected by:

• Cold
• Heat
• Altitude

How does the cold affect paddle board psi?

If you were to use or store your paddle board inflated outdoors over winter, you can expect the air pressure inside your sup to decrease.

We couldn’t find any specific info on exactly by how much but Goodyear, the manufacturer of car tires, has this to say about psi loss in cold weather for their tyres.

For every 10 degrees of temperature drop, tires will drop 1-2 pounds of pressure.

Inflatable kayak users in colder climes i.e. Canada, often report having to top up the air pressure in their kayak’s main chamber.

There’s a great discussion about it on this paddling forum.

So, if cold water and cold air reduces psi in inflatable kayaks, it makes sense it will in paddle boards too.

And, the way to overcome this when paddle boarding in winter or extreme cold, is to let your paddle board sit on the water in the ambient conditions for about 10 minutes. Then pump it back up to the recommended psi. You should then be good to go.

How can heat affect paddle board psi?

Keeping or using your paddle board inflated in a very hot environment can cause the air pressure inside the paddle board to increase. This can add as much as an extra 2 psi to your board.

Most paddle boards have a little expansion room so, provided you haven’t inflated your sup board above its manufacturer’s psi guidelines, it shouldn’t be an issue.

However, if you intend to store your paddle board inflated in a hot environment, most experts recommend letting some of the air out of your board before putting it away.

Does paddle board psi change with altitude?

Here’s a chart from science.howstuffworks.com showing how psi decreases the higher you get.

So, what does this mean for your paddle board?

Well, from what we understand, it means that anybody wanting to SUP down the side of Mount Everest (at 29,030 feet) might be able to get away with pumping their board up to just 4.4psi. As we have trouble using a pump at sea level, this is not an experiment we’re going to attempt any time soon.

However, joking aside, we should actually be looking at what psi figure is suitable for effective paddle board performance on water. Performance, as we’ve seen already, requires stiffness and rigidity. Would 4.4 psi at 30,000 feet achieve that?

To be honest, unless you plan on stand up paddle boarding on lakes and rivers in the Himalayas or the Andes, altitude will make little difference to your paddle board psi.

At altitude, you might find you can get away with less psi. Unfortunately, though, due to the thinner air, you might also find you have to do the same amount of pumps as you would to get it to the recommended psi at sea level.

Bah!

Aside: It might also explain why a recommended psi of approx 15 psi seems to be the norm. Looking at the chart, that’s roughly the air pressure at sea level.

Can I leave my stand up paddle board inflated?

Yes, you can. But it depends on where you store it and how inflated it is.

Our paddle board supplier, twobarefeet, recommends complete deflation.

Many other experts and paddle board faqs on the internet, claim storing your paddle board pumped up isn’t an issue. It’s unlikely to deteriorate, weaken or cause any internal damage to the paddle board – provided you’re careful where and how you store it.

Will storing it inflated affect your paddleboard’s psi?

If you store it inflated in a hot environment, then you might want to let some air out to allow for the natural increase in psi caused by the heat.

If you store it outside in winter, you might find it loses some pressure and you’ll need to top it up before use.

Finally! The Pressure’s Off

So, there you have it. Everything you needed to know about paddle board psi, and plenty you didn’t.

Hopefully, it will clear up any doubt, confusion or questions you have about your inflatable sup and that pesky, invisible, but vital stuff that fills it…air.

Unfortunately, what this paddle board psi guide won’t do is help you inflate it.

Sorry.

That bit, you’ll just have to do yourself.

Cheers!