The patch of grass next to the concrete I wash bikes on is getting a bit overloaded.

I’m considering digging a trench and filling with pebbles of some sort to try to ease the runoff issue.

It’s probably about 9′ long and normally I’d only need to wash bikes a couple of times a week, I’m doing it more often right now as I’m still off work from Christmas 🙂 No jet washes in use, just garden hose and bucket of soapy water. Any thoughts on how wide and deep so I can estimate how much I’ll need to fill it with and hence what it will cost?

Thanks!

Pulls up chair, in the exact same boat. Will watch with interest.

start by measuring how much water you use in a ‘wash’
so 3 x 5L buckets and 3mins of hose?

i’d guess that double your answer would cope admirably

Depends on the soil under. If it’s quite clayey and doesn’t drain well the trench won’t really assist if the water hasn’t got anywhere to go.

i’m assuming at some point the “saok away” will fill with silt!? It’s amazing how much non-garden mud has accumulated in my garden.

It does drain reasonably well eventually. There’s a monster land drain under that area already, it’s more about minimising muddy soggy grass and subsequent dirty dog paw prints than an area that stubbornly won’t drain.

My unscientific first idea was maybe about a foot wide and deep, so giving a volume of around 125 litres (I think?). Not sure how that translates into water handling once full of gravel though, as the water is going to have the spaces between matter to occupy rather than full volume. Is there some sort of fudge factor for guestimating this?

Is there an option to wash the bike somewhere else, or at least rinse it somewhere else? I would think your plan above is only going to give temporary relief and the time spent doing it could be spend riding your bike.

Could you use a garden fork to put loads of holes in the lawn, fill those with coarse sand to stop them collapsing, then the water will flow into those and soak away rather than wash over the top of the lawn?

Lawn aeriation

It’s a patch of grass between the kitchen and the shed that I’m not too precious about, but I’m just trying to minimise collateral damage from bike wash. For all other purposes it’s the best place for the job really – out of sight of road, good access to hose and kitchen door etc…

Will have a think about it.

I knew reservoir engineering would finally be usful for mountain biking. Perfect spheres, randomly packed have a porosity of around 40%, given that gravel is not perfectly spherical and the gaps will also fill with smaller particles, I estimate about 30% of your volume will be available for water.

If you can find some bigger lumps to put into the base of the trench, they will have larger voids and a lower propensity to silt up.

I did similar about 5 years ago. Lots of advice here about how to do it properly.

In the end I dug down about a foot and filled what I had with pea shingle. It only really got saturated after very heavy rainfall AND washing my bike. The trench would only have been about 2 foot wide at its widest (flower bed bound by concrete edging one side, concrete slab on other) and about 6 ft long.

After about 5 years of washing a muddy bike about twice a week the gravel could have benefitted from being dug up and replaced, but I built decking over it and sold the house in the end.

Pieface – Member
After about 5 years of washing a muddy bike about twice a week the gravel could have benefitted from being dug up and replaced, but I built decking over it and sold the house in the end.

I think you picked the more expensive and stressful option there. Just saying, for future reference.

use the bath

Thanks everybody! I think I’ve got a plan now.

Oh, the bath? I thought that was reserved for tyre changes on tubeless wheels… 😀

Have a look here…

http://www.pavingexpert.com/drain14.htm

The guys on Pavingexpert know their stuff. As I posted earlier, if you haven’t got a perforated pipe drain, you could use bigger bits of rubble in the bottom of the trench to try to get bigger voids.