I helped the boy make some shelves this week. He graduated college and is moving into a house so were trying to get him all organized. Here is a simple design if you want to copy it. $500 in material at Lowes.

do you come back and put some 2x4 blocks between the shelves on the back side of the uprights?

if not isn't all your sear load on the fasteners?

It would appear so....I'd have a hard time finding stuff in the back with those wide shelves, lol

I just get the plastic 5 shelf ones from harbor freight when they go on sale.....plenty strong, not too wide and you can move them to wherever you want....

Im not sure what your asking Pete. Roughly 2x6's every four feet. Then the long shelf has 16' 2x4's fastened to each 2x6 with a couple 3" deck screws.

I put the 2x6 on the wall then I set tubs on the ground, layed a 1.5" high side of a 2x4 on top of the tubs for spacer, and then ran 3.5" high side of a 2x4 on top of that, and fastened that one to the 2x6 on the wall.

So that got my first board across the bottom. Then I stood up 2x6's and did that for the front. So a tub on the ground has 1.5" of clearance to the bottom of the 2x4 sliding in.

So anyway then you get your first two big long runs of 2x4 up and then I cut 48" and 45" boards and tied them together every 4' and on the ends.

Then we just threw a sheet of plywood on top and screwed it into the 2x4 runners. I left the plywood a full 4'. Mine at home has two 4' shelves for a work bench and then two 2' shelfs above and back for shelving.

Moved our tubs from the floor to shelf one, put on spacer 2x4, and started a couple more runners. Tied them in every four feet. Rinse and repeat.

The 2x6 all have 2 tapcon screws into the basement walls. You can walk on it, so it holds tubs. I used clear tubs; have a plumbing tub, electrical tub, construction tub, dewalt tub, canning tub, butcher tub... You can see whats in the tubs when your "shopping".

Gluing it didn't seem necessary.

Pete's point is that all your load is relying on the sheer strength of your fasteners. Screws aren't designed for sheer strength. Nails would be better.

He was asking if you would put stub 2x's vertically, so the shelf runners would sit on the 2x4. This way the 2x4 would bear the load, instead of the screws.

8 foot seems like an awful long span, unsupported.

Yeah Im 6-1 and my 4' wide work bench has outlets on the back of it that are hard to reach but I got plenty of room. When I came up with this for my work bench I did it 32' long and think of it as assembly line stations. i.e. I have a bay of gardening stuff that sits on the workbench but thats where it belongs. I use that bay when Im gardening. The idea I was shooting for was when I get all my fishing jigs out to paint and then clean all that up and put it away. I wanted a spot I could just leave it out.

These shelves are six tubs wide and two tubs deep. Reaching the second tub isn't reaching four feet, its only reaching two feet.

oh i see. yeah you could do that. Thats not how I've done it in the past and haven't had any trouble but I make sure to get good shots with my screws. You can walk and climb on it. Maybe if a corner busts loose or something and gives me trouble it'd be easy enough to go through and block it in like you are saying but were holding tubs of nick nacks organizing a house not feed bags of grain.

I got organized once.

Based on this one thats been going for about five years. I need a pic after cleaning up but you get the idea.

until you catch that great sale on rice or do a ton of canning and fill a shelf with 200 canning jars full of the good stuff
each 4x8 foot shelf will hold 288 quart mason jars at 3 pounds each and that is a single layer you have room for a double layer easily

288 canning jars full of water at 3 pounds each is 864 pounds your shelf easily has space for a double layer 1728 pounds.

I may be know for going a bit above and beyond in all things I construct. if it needs to hold 300 pounds you will easily put 900 there.

when you look at wall loads , you always put a jack stud next to a king stud when framing a window or door , to transfer the load of the top plate clear to the bottom plate.
and cripple studs above the header and header resting on the jack studs

by placing blocking between the floor and shelf and each shelf that fits snug you are creating a split jack stud and you take the weight off your fasteners and place it down through the split jack studs. very minimal amount more wood to make a huge difference in weight carrying capacity.

it's all fun and games when you are stacking sleeping bags that don't weigh much , but when you start stacking flats of shotgun shells , ammo cans , or canning jars full of food your load can change very fast.