Maybe an outdoor shower? Get the sand off before they hit the stairs?

I like hand painted stairs. A great look and no rug!

I would think about getting faux sisal carpeting for your runner which will give it a very beachy look and will wear better than real sisal or jute. You could even get it bound with canvas tape in a contrasting color, like navy or burgundy. Most of the big carpet manufacturers make them; just need to find one with the right pattern and tone.

Here are a couple of examples:

I love all these! we do shower outside. we leave shoes at the door. there is no way to keep the sand down. and surprisingly, i also see hairs on the stairs all the time (on the white sides).

these are hand painted white stairs. they looked awesome before the rug went down but crazy dirty ALL. THE. TIME.

The rug is ripping because it's a thin flat weave rug and wasn't designed for stairs. (I used 2 runners that I bought from urban outfitters.)

my question is where can i find broad loom colorful interesting carpet? it can't be a runner. I don't want any exposed wood.

There are many options out there in wall to wall carpet; perhaps your dealer doesn't carry enough lines?

I'm looking online, they said they can order from most anywhere. All the patterned options I have found are muted or earth tones. I'd love to find something in pink or teal, multicolored. Fun! It seems in general, broad loom carpeting is subdued and toned down.

I would agree that paint is a better option. The sand will become ingrained in the carpeting and probably impossible to vacuum.

One easy option might be these!

Hi nouterbud, we’re happy to recommend some solutions for
your stairs at your beach house. We offer a wide variety of carpet styles,
patterns and colors, but in looking what you have here, we’ve recommended the
following for you. Keep in mind we’ve also made sure these selections can take
the heavy foot traffic of steps, which can oftentimes wear down with time if
the wrong carpet fiber is selected.

Constant
Synergy – a traditional diamond pattern modernized with the addition of
an unexpected striated background and available in 20 colors including bright corals, blues, yellows and greens as well as more neutral options. The carpet fiber is
Anso Crush Resister Nylon with R2X and also features the waterproof LifeGuard
backing.

Defined
Beauty – a geometric octagon pattern available in 18 colors. The carpet
fiber is Anso Crush Resister Nylon with R2X and also features the waterproof
LifeGuard backing.

Tuftex
Taza II – a Moroccan inspired design that features color variations of
striated yarns. The carpet fiber is Stainmaster Active Family and it’s
available in 16 colors.

Hope this helps your search!

I would not carpet stairs in a beach house.

There's nothing magical about 'broadloom'. It just means a wide loom (12 feet is the standard). Any wall-to-wall carpet is broadloom.

Long ago, there wasn't the technology to make wide carpets, so rooms were done in strips of narrower carpet seamed together.

Check out Shaw hospitality.

Shaw...

Final product. Several 5x7 area rugs, cut to fit the stairs.