Making Closet Shelves with Oriented Strand Board (OSB)

I’ve had a home improvement project that I’ve been avoiding for quite some time now. The project has to do with making shelves for the insides of the kitchen cabinets, the laundry room, three bedroom closets and a hallway closet. In all, I’d say we need about 15-20 shelves. All different shapes and sizes, mind you. As you can see, many areas of our house came without shelves for some reason. While we’ve been making do, life sure would be a lot more fun with a whole bunch of shelves hanging around.

The reason I’ve been avoiding this whole ordeal is two-fold. First, I didn’t want to spend $300 on a table saw. I’ve spent my life making crooked cuts in plywood and I really had no interest in making any more. A table saw offers a fairly fool-proof method for making straight cuts, but the saw is expensive (and challenging to work with by yourself). Second, plywood is expensive. For the cheapest 3/4 inch CDX fir, I’d be laying out $34. That’s a lot for a few shelves, considering I would need about four sheets. The reason I wanted to go with 3/4 inch is because there’s less of a chance of sag. I can make a longer run without any reinforcement and have things stay fairly straight.

About a week ago, I decided to get serious. Things around here have been sitting on the floor for far too long and it was about time for me to take action. I began looking for a table saw in earnest. I was even ready to hop in the car to go pick one up.

As I was looking around online, I stumbled across this really neat tool. It’s called a Kreg Rip-Cut and it attaches to pretty much any circular saw. It’s a guide that keeps rip cuts perfectly straight, as long as you’re already working with a straight board. Given the fact that plywood comes from the store as straight as it’s going to get and considering I have a really sweet circular saw, I took interest in this particular tool. I ordered it from Amazon for about $25. Don’t worry, I’ll show some photos of it below.

Since this part of my issue was almost solved, I decided to move on to the cost of the wood. What I really wanted to learn about was the difference between regular plywood and oriented strand board, or OSB. You may have heard of this type of wood under a different name. It’s also called flakeboard, sterling board and aspenite. In the most basic sense, it’s a bunch of flakes of wood that are glued together in different directions. It’s not particle board – that’s sawdust that’s been glued together. This wood uses flakes. Here, take a gander at what I’m referring to.

From what I found online, OSB is becoming wildly popular because of its strength and low cost. It has very similar rigidity to regular plywood, but costs much less. I did a bit of calling around and I found some 3/4 inch for only $22 per sheet. That’s $12 less than the plywood. The downside is that it swells when it gets wet. Many producers have somewhat solved this issue though, because they are now using a different type of glue to hold the flakes together. And since I’m using this stuff indoors, I really don’t have to think about that part of things.

After I received my new Kreg tool, along with a bunch of Irwin wood clamps, I ran out to the lumber store for some wood. I picked up ten 2x4s, one sheet of 1-inch rigid foam insulation and three sheets of OSB. I think I spent around $125 for everything. I was rather proud of myself because all of my new tools in combination with the materials I need for the project came up less than just the table saw. That’s really not bad.

In order for me to effectively use the Kreg tool, I’d need a table. Since I made some really awesome sawhorses a while back, I decided to use them as a foundation. Once I moved them into position, I cut one of the 2x4s in half and screwed each half to one of the horses. Then, I attached four more 2x4s to the ones I just put down.

I was also sure to make the table as exactly square as possible.

After I was finished with the frame, I added the piece of one-inch rigid foam insulation.

Now, I know you must be asking yourself what in the heck I’m up to. Well, the idea is genius. Since I’m only one person and since the OSB is heavy and cumbersome, I wouldn’t be able to cut it into pieces by myself without it being supported. If I were to try, terrible things would happen. Trust me. It’s awful cutting wood like this when there’s nothing underneath.

Since rigid foam won’t dull a circular saw blade, I could lay the OSB on top of the foam and adjust the blade so it just touches the foam, but at the same time, cuts all the way through the wood. The frame I made would support the weight and the foam would act as a bed to catch the wood after I’m finished cutting through it. It’s beautiful to think about.

I’ve already worked on this table for a few days, so please forgive all the dust. What I want you to notice here are the small incisions in the foam. Those are where the saw blade hit it.

Once the foam is set up, all that needs to be done is to lay the wood on top of it. Clamp it down so it won’t move, measure and begin ripping.

Today’s project required that I cut eight strips of wood that would act as the supports for the closet shelves. These strips measured 2 inches by 36 inches. To achieve these perfectly wonderful and exactly straight strips of OSB, I’d have to set the saw guide to 2 inches and cut. I did that. Look what I produced.

I swear, I never cut anything so straight in my life. If I had a nice 60-tooth blade, the cuts would have been even smoother.

Okay, it’s about time I show you the Kreg Rip-Cut tool, so you know what in the world I’m talking about.

As you can see, I’ve got the Kreg Rip-Cut tool attached to my Milwaukee circular saw. It bolts right on the front and it offers a very precise ruler, once it’s calibrated with the saw blade.

When it’s attached correctly to a saw, it merely acts as a guide, so anyone can easily and smoothly rip a piece of plywood in, up to, two foot sections. The ruler is only 24 inches, so you can basically cut a piece of plywood in half, lengthwise. For cutting strips of OSB and the shelves themselves, this is absolutely perfect. And it’s the right price, to boot!

Here’s a better photo of just the sliding ruler part of the tool.

To cut the strips, I ripped four pieces, eight feet long. Then, I clamped all four pieces down next to each other on my foam table.

Once each piece was lined up and clamped down, I measured the 36 inches and made my line. I pulled the ruler part of the Kreg tool out and used my quick square to cut the long pieces shorter. Using this method gave me an exactly even cut for all pieces.

I gotta be honest with you here. About half way through this project, I realized that my days of crooked cuts are over. I’m a measuring and straight cutting fool now. The proper foundation and the right tools make all the difference.

For the shelves themselves, I used a piece of straight wood I had leftover from a previous day. I again removed the ruler part of the Kreg tool and made my measurements. I clamped the straight edge down and made my cuts.

After I was finished with all my cuts, I brought the lumber inside. I really wish I had a lot of photos to show you, but all I managed to get was some lousy ones from the hallway closet. It was just too dark in the bedroom. I’ll have to get a light in there because that’s where the fun is. I installed a copper pipe hanger rod and three really great shelves. I’d like to show that off.

As for this closet, this is how I mounted the shelf supports.

After they were in, I simply placed the shelves on top of them.

If it looks like anything is crooked, it’s because the house is. I used a level and a tape measure ad nauseum and I can guarantee the shelves are straight. The only issue is that they stick out from the supports about a half-inch because the OSB lumber I purchased was tongue and groove. I left the tongue on and it’s at the back of the shelf.

Also, I was going to rip some 2x4s to attach to the underside of the shelves to avoid sagging, but I don’t think I’m going to need to do that. The OSB had a slight curve to it and luckily, it’s facing upward. Any sagging would just make the shelves straight.

So, how’d I do? If you have any comments or questions, please leave them below. Thanks for reading!