I don't think there's going to be much of a difference. Just go with whatever your supplier charges by. I just did this and had my supplier do a 1:1 by yard. Worked well. Have them screen the topsoil through the sand screen/trommel if they can. Even if they charge extra, it's worth it. Also have them mix it for you. My supplier charged me an extra $25. Well worth it.

 

What's your goal? filling in deep ruts or just leveling bumpy lawn? I would do straight sand if latter. If you got 2-3"+ ruts, I would spot level a soil mix first.

 

I've already got the soil and sand, and I'm just smoothing out some bumpy areas. Just want to know if I should mix batches by weight, say 40 lbs of each, or by volume, a 5 gallon bucket of each. Because a 5 gallon bucket of sand weighs a good amount more than a 5 gallon bucket of topsoil.

 

are you seeding as well?

I wouldn’t overthink it. Personally I would I would go heavier with soil ratio on deeper spots.
Dirt doesn’t spread and smooth as well so a higher sand ratio is better for skimming shallow variations.

 

I appreciate all the replies, but I'm really just wondering as a general rule, not just for my situation. In gardening/landscaping, whenever you see recipes for ratios of stuff being put on a lawn or in a garden bed or wherever, be it topsoil, compost, sand, peat moss, worm castings, cow manure, perlite, etc., is it generally understood that "by volume" is what is meant? I assume so, but I never see it specified as such anywhere.

 

It’s not that simple. If you go to a big box store, you’ll generally find supplies in either 1cu foot or bags sized by pounds. Most soil products come recommended in volume (cubic ft or yards) because of the ability to hold water. So you’d need to read the label to see a 50lb bag = .75cuft. In bulk material (quarry) it’s all sold in volume.
But as others have pointed out, if you’re trying to mix materials the ratio blend should match the intended purpose. Your original post said you’re trying create a leveling mix- in that scenario a 1:1 ratio is horrible for leveling. It should be much closer to 8-9:1 all the way up to 100% sand.

 

I'd think it would be by volume, not weight.

 

I don't have a scientific recommendation for you, but I can tell you what I did, and it worked out well:

I had depressions ranging from about 0.5" to 4", very bumpy.
Because of this large range, I kept my ratio the same. I am not at a stage of just top dressing with 100% sand. I ordered 3 yards of topsoil and 2 yards of Mason sand, and I had about a yard of sand left over

Someone on this forum mentioned if you have depressions greater than an inch, don't use pure sand and go 50/50 instead (source needed).

I wasn't about to do anymore math at that point. I started by using a 3 to 1 soil to sand ratio, mixed it, and looked/felt the consistency with my hands. It felt and looked very sandy, so I went with 4 to 1, and it looked like this (4 shovels of dirt, 1 shovel of sand)

With a goal HOC of 1.75, some areas were completely smothered so I had to re-seed. Other areas did well and everything held.

Results 1 week apart

This may or may not help you but I thought I'd share my experience. Good luck!

 

joec - Yes, that's definitely helpful. Thanks for taking the time to post all your stuff. Lawn looks real nice.

I'm not really thinking much about this at all actually. I'm not sitting here wringing my hands and fretting about it. With all these various recipes/ratios for gardens, topdressing lawns, container gardening, etc., you never see anyone specify weight or volume. Granted, for things that generally weigh the same, it won't make much difference. But say sand and peat moss...a bucket of each will have vastly different weights. Everybody who mixes up a batch of whatever must use one of the two methods, so just wanted to know what the default was.

 

I'm not trying to reel mow or anything, just fill the deeper parts in my lawn (mostly from root decay from a few trees that were removed). I just buy he playbox sand from Home Depot and mix about half a bag to a full bag of topsoil I pick up. Add a wheel barrow load to my suspect areas every couple of weeks and work it in. Noticeable improvement in walking around the yard, no discernible decline in grass. Could it be better with better sand? Maybe. But I'm playing the long game here and going slow with it by grabbing a bag of two of each when I happen to be at Home Depot.