Build Greenhouse Shelves

Add Stops to my Workbench

On the upper corner of my bench I attached two strips of plywood at 90 degrees. This will make stops to hold the brace pieces at right angles while I assemble them.

Checking the angle of the temporary stops screwed to the workbench
Checking the angle of the temporary stops screwed to the workbench

To support the angled brace piece of the shelf bracket I attached a half inch thick piece of particle board to the bench top. This will lift the brace piece so it is centered. As it is lying on its side.

Screwing a 1/2" particle board lift to workbench
Screwing a 1/2″ particle board lift to workbench

Next, I’ll add some pencil lines for my screw locations. I set my combination square to half the 2×3 width. You could really just eyeball these, it’s not critical.

Marking screw locations with a combination square
Marking screw locations with a combination square

I like to drill pilot holes with a one eighth bit — even though I’ll be using self-drilling GRK screws for assembly. I just find it pulls the parts tighter together this way.

Drilling pilot holes in the shelf brace parts
Drilling pilot holes in the shelf brace parts

Assemble the Greenhouse Lower Shelf Brackets

And I’ll add some exterior wood glue at the mating surfaces.

Applying glue to the shelf bracket parts
Applying glue to the shelf bracket parts

I’ve been criticized in other videos for using glue on end grain like this. I know it doesn’t add much additional strength to the joint but, it does seal the gap (if any), and should help prevent water from seeping into the end grain of the wood. So for that alone, I’ll keep adding glue far all this assembly.

And I’m using #9 2-1/2″ GRK screws to assemble these brackets and the upper and lower shelfs.

GRK screws I selected for the shelf bracket assembly
GRK screws I selected for the shelf bracket assembly

To attach these brackets to the studs in the greenhouse, I’ll use some 5/16″ x 4″ GRK washer-head lag screws. I’ll drill two pilot holes in the bracket now.

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GRK washer head lag screws for attachment of the shelf braces to the greenhouse stud walls
GRK washer head lag screws for attachment of the shelf braces to the greenhouse stud walls

The upper pilot hole on a slight angle so my driver and bit will clear the angle brace.

Cutting Pieces for the Lower Shelf

Now I’ll cut some 2×3’s for the cross members of the bottom shelf.

Cutting the parts for the lower shelf cross members
Cutting the parts for the lower shelf cross members

And the front edge of the shelf is a 2×4. I decided to make this unsupported front edge thicker to reduce any sag that we might get with a loaded shelf.

This 2×4 is cut to length then taken to the bandsaw to have two additional cuts on each end. This is so the front edge sits at the same level as the 2×3’s. And I like the look. A jigsaw could also be used to make these cuts. Or even a handsaw.

Cutting the 2x4 front edge of the lower shelf on the bandsaw
Cutting the 2×4 front edge of the lower shelf on the bandsaw
Cutting the 2x4 front edge of the lower shelf on the bandsaw
Cutting the 2×4 front edge of the lower shelf on the bandsaw

Layout the Lower Shelf Parts

I can now lay out these pieces of the lower shelf on the bench. I cut a 45 degree brace for each corner.

Laying out the parts for the lower greenhouse shelf
Laying out the parts for the lower greenhouse shelf

I marked and drilled pilot holes then I started a screw in each of these. Then add glue and screw it all together. And the stops on the bench helped to keep everything square as I went along.

Assembling the lower shelf with screws
Assembling the lower shelf with screws

And finally those two corner braces are added. Then the final missing screws on the front. Those holes were covered by my plywood stops.

The lower shelf complete
The lower shelf complete

The bottom shelf is built in two 4 foot long sections. This was to make assembly and placement on the brackets easier for me.

Assemble the Upper Greenhouse Shelf

The upper shelf is made in one 8 foot long section as it’s only 12 inches wide.

Laying out the upper shelf on the workbench
Laying out the upper shelf on the workbench

I can now lay these pieces on the bench and get ready for assembly. And like the lower shelf I marked then drilled pilot holes, started the screws, added glue, then methodically screwed it all together.

Assembling the upper shelf 2x3 parts with glue and GRK screws
Assembling the upper shelf 2×3 parts with glue and GRK screws

Upper Shelf Simple Braces

This upper shelf has 4 braces to support it. I’ll cut those now on the miter saw. A 30 degree on one end. Then a 60 on the other. And I can use a small speed square to mark these before cutting.

Using a small speed square to mark cuts for the upper shelf braces
Using a small speed square to mark cuts for the upper shelf braces
Cutting the upper shelf braces on the miter saw
Cutting the upper shelf braces on the miter saw

The 30 degree cut end will be attached to the underside of one of the shelf cross members. And the other end will be screwed to the stud in the greenhouse.

I used a drill block for the hole in the 60 degree cut end. I made a cross with pencil on this angled cut — then held the drill block in place to drill the pilot hole.

Using a drill block guide for pilot holes in the upper shelf braces
Using a drill block guide for pilot holes in the upper shelf braces

And this was easy to do as there’s a large flat spot for the drill guide. And the hole was perpendicular to the face.

Improvised Drill Guide

For the other end, I would need to angle the pilot hole. To help with this, I made my own improvised drill guide. I first drilled a hole with the drill block through a short piece of 2×3. Then on my miter saw I cut the block at a 30 degree angle.

An improvised drill block to aid in drilling an angled pilot hole in the upper shelf brace
An improvised drill block to aid in drilling an angled pilot hole in the upper shelf brace
Drilling a pilot hole using and improvised DIY drill block
Drilling a pilot hole using and improvised DIY drill block

Pencil marks on this block help me line things up. And this worked well enough. It got my pilot hole in roughly the spot I wanted to attach this brace.

And I can then countersink those pilot holes to allow for the screw head. Now I’ll apply some glue and run in a #10 x 4″ screw. And I’ll check that placement with a framing square.

Countersinking the brace pilot holes for the screw heads
Countersinking the brace pilot holes for the screw heads
GRK screws I selected for attaching the braces to the shelf
GRK screws I selected for attaching the braces to the shelf

I’ll repeat those steps for the remaining three braces. I did decide to add an additional screw at this location to keep the brace from rotating while the glue was setting up.

Adding one additional screw to the brace
Adding one additional screw to the brace
Adding one additional screw to the brace
Adding one additional screw to the brace
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