My first real project - garage ceiling shelving

cowboyplus · Post by **cowboyplus** » Mon May 19, 2008 11:19 am

I see impending disaster with vertical load on screws into end grain, glued or not. “T” straps will be required on each side of the vertical load bearing 2x4’s, ceiling and rack ends (4 each vertical support).

brown_hawk · Post by **brown_hawk** » Mon May 19, 2008 11:26 am

chrispitude wrote:...

Do I want to do anything special like let the glue set up a little bit first before pulling the joint tight?

- Chris

Chris, one of the shop tips in the SS site has a recommendation for gluing end grains: Put ehe glue on and let it sit for 1/2 hour, then reapply and glue as normal. This should let the glue soak into the fiberous ends and result in a stronger bond than if the joint is glued and screwed immediately. The immediate joining can cause glue starvation.

One other recommendation I ran into on the internet was the Gorilla Glue type. (Sorry Nick). Since this glue expands, supposedly it would grip the fibers better and not shrink, maintaining a stronger bond. That's actually the only recommendation for GG for woodworking that makes any case for it being better than Titebond types. (But still messier.)

Since my cabinets will be using a lot of end to end gluing, I've been looking at this. My own decision right now is to use the first recommendation, and let the glue dry on the end grain. Just thought I'd throw the other in for info purposes. I really don't have time for a test of the two methods.

Also, you need to keep in mind that end grain needs a different type of screw than normal. I don't remember the type, but more like drywall, I think. And a drop of glue on the end of the screw as well. But keep in mind that I haven't done much research on screws into end grain, just what I have come across when researching end-to-end joining.

Looks good so far.

Hawk

ETA Might want to look at pocket hole screwing, going into the cross piece. That way the screw in going into the long grain not the end grain. I know you've got the other set up, but adding that could add some strength if you are worried along those lines.

brown_hawk · Post by **brown_hawk** » Mon May 19, 2008 11:57 am

[quote="cowboyplus"]I see impending disaster with vertical load on screws into end grain, glued or not. &#8220]

Chris,

The more I think on this, the better I like Cowboy's idea. If not T straps, angled wood braces or just a strip of wood covering the joint and screws glued and drilled horizontially inside and outside, so that you have what Ed in Tampa recommended, screws that have to be sheared for failure.

Forget the pocket holes, those are for furniture. For this you want your great grandchildren cursing your name when they try to take it apart.

Or strong enough for them to swing from, which they will.

Hawk

chrispitude · Post by **chrispitude** » Mon May 19, 2008 5:02 pm

cowboyplus wrote:I see impending disaster with vertical load on screws into end grain, glued or not. “T” straps will be required on each side of the vertical load bearing 2x4’s, ceiling and rack ends (4 each vertical support).

Hi cowboyplus,

I viewed the screws only as a means to an end - to draw the joint together so the glue could take hold - and not as the primary means of weight support itself. I remembered reading that wood glue is stronger than wood once it cures, so I figured I was okay. However, I see what you mean about the end grain still not being the vertical support's strongest axis, and I am leaning towards doing something along the lines of your suggestions. Thanks for your feedback!

By the way, the plans in Workbench magazine for this shelving did use this glue and screw approach, but they have more vertical supports than I do (they'd have three instead of two per side, according to their plans).

- Chris

cowboyplus · Post by **cowboyplus** » Mon May 19, 2008 8:30 pm

Primary is the load that will be applied to the shelf. The weight limit of your shelf deck is 40 - 50 times the weight limit of your vertical supports, indicating you anticipate a hefty load. The dado into the rail 2x4’s has weakened the 2x4 as to it’s length sheer factor in relation to the load. No doubt the glue would still be holding to the vertical supports after a load failure, along with the lower length of the sheared rail 2x4 at the dato depth.

I think of safety. Vertical hanging support details (calculations) require the utmost finesse. Reminds me of the formerly renown building engineering firm in the mid west whose mezzanine steel rod vertical from the roof support threads stripped and killed many in the wedding party that had innocently gathered to view the atrium, exceeding the anticipated the load limit, of the hotel they had designed.

a1gutterman · Post by **a1gutterman** » Mon May 19, 2008 11:25 pm

Hi Chris,
I have to agree with the fella's here: Your design is not the best for supporting any substantial weight. Using "T" straps (plumbers tape wood do well here too; just wrap it around the horizontal 2X4's, while attaching it to both sides of the vertical pieces), will go a long way of providing adequate shelf strength. Using lag bolts will probably do the job up at the ceiling, but please make sure you center the bolt on the joist, and (you probably planned on doing this) drill pilot holes in the ceiling joists. And I wood probably reinforce the upper dado joints with the same method that you use on the lower dado joints. I am sure that your shelves will be a great addition to your shop!:D

dusty · Post by **dusty** » Tue May 20, 2008 7:20 am

And....don't put those engine blocks up there!

brown_hawk · Post by **brown_hawk** » Tue May 20, 2008 8:19 am

dusty wrote:And....don't put those engine blocks up there!

Dusty, some days you're a real kill joy!:D

Hawk

dusty · Post by **dusty** » Sat May 31, 2008 8:19 pm

OK Chris;

How's it going?

chrispitude · Post by **chrispitude** » Tue Jun 03, 2008 6:39 pm

Hi dusty,

I really want to get back to this project this weekend. I've been distracted by some outdoor yard work that really needed done, but I'm hoping to find time this weekend to finally get some lumber on that ceiling!

Fingers crossed...

- Chris