Attachment to Hardi-Plank

[Superman]

As some of you know, my profession brought me into the orbits of the building and construction trade unions whose skills I came to admire, particularly those of Sheet Metal Workers. Among their skills is making stuff out of stainless sheet metal. I had these shelves made by an apprentice. They are always looking for projects for apprentices, particularly if someone is willing to pay for the materials. Some of the stuff they fabricate are basically building jewelry. Sometimes just stunning. Google their work to see. These shelves are not in that category but they will be quite functional if I can properly attach them.

They will go on an exterior wall and the most convenient locations will be on the windward sides of the house where they will be exposed to the elements. We could put garden and patio tools on them, plants, etc.

This board is literally known throughout the world for its ability to answer the most esoteric of questions and while this question (attaching stuff to Hardi-Plank siding) is not as challenging as how to replace rear tail light lenses on a 1913 Stutz Bearcat, I'd like to get input here on my simple question.

[herr_oberst]

(edit, never mind. I see that the photo perspective made me see something that wasn't there)

[masraum]

I assume the first/top pic is of the underside.

Is there a "lip" under the main shelf? If so, I'd go with something similar to a French cleat. A piece of wood or metal screwed through the hardi into studs behind the hardi that catches the lip. French cleats are VERY sturdy. This wouldn't exactly be a French cleat since those are normally wood at an angle, but should be very similar (if there's a vertical lip that runs the length of the shelf under the shelf.

[TimT]

Those are cool, they can be hung blind..

Make some cleats...secure cleats to sheathing or stud (not the hardi board)

Hang the shelves

[masraum]

Metal would be my choice is possible/available, but wood would work too.

If the top bit (the shelf), has a lip under the shelf, then a cleat should hold it up securely.

[herr_oberst]

Tim, Steve, you're seeing the same thing I saw initially. In fact, my first post was basically what Tim sketched, "go back to the sheet metal shop and get some z-metal bent to hang it blind."

However, if you look at the photo, there's only one flange, and it's up; the only thing at this point, is which exposed fasteners to use. Something stainless, and with a good looking head. My preference would be a stainless button headed fastener.

[carambola]

Maybe a tile or glass bit to penetrate the Hardi-Plank, see if there is any play behind the siding and sheathing to avoid cracking and support from the structure.

[Alan A]

https://gsexteriorexperts.com/how-to-attach-something-to-hardie-board/

[Superman]

These might help. The top picture is right side up. The bottom picture is upside down.
There is a lip on the back of the shelf above the shelf surface, but no lip below. I might want to use two or three fasteners along that lip, penetrating the lip itself, and fasteners underneath the shelf at the bottom of the lip there.




I wonder what fasteners to use, and how to use them. I could use something that has a screw head on it, but a button-head might look better. I would need to drill first and install it with a hammer, basically. Hm....

If I drill, then what kind of bit do I use? Hardi-Plank is semi-cementitious.

And then do I use a bit of silicone to waterproof? And/or do I use a rubber washer between the sheet metal and the siding? Don't tell me I am overthinking this. I already know that.

If I am to put a fastener through the sheet metal, then I will need to drill that. Carefully, so as to avoid bending the sheet metal.

[herr_oberst]

How wide is the shelf? There's studs behind that wall, they s/b on 16" centers.

Another option (if you can use the studs in the wall to grip the fastener) is to use a SS hangar bolt; gives you the option to use a nice looking acorn nut for the exposed fastener. Others may weigh in, but with Hardi, do you need to worry about spacing the shelf from the wall? What's going to rot?

[herr_oberst]

By the way, those are really nice looking shelves...

[Superman]

Thanks, Mike. These shelves look nice, but are not prime examples of what they can do. I saw a podium they did. All the welds were undetectable. Some surfaces were matte, perhaps soda blasted or something. Some surfaces were done using a grinding wheel. All the corners and edges were polished to mirror finish. It was breathtaking.

Another piece I saw included scene done on a panel depicting a beach scene with sand and water and palm trees and a Sun in the sky. Done using grinding wheels mostly.

[70SATMan]

I’d use Mollys. The Hardi board is more than strong enough to support most anything you plan to put on those shelves unless it’s stacks of gold bars but, I wouldn’t use anything tapped into that. Standard bit will work fine. Though it has cement, it’s actually cement infused paper fiber. You don’t need a masonry bit. If you want to get fancy, a carbide tipped bit will do the trick pretty cleanly.

If you have full sheathing behind the Hardi, then you could even drill a through hole in the Hardi and then use stainless wood screws into the ply. The mollys though will be the strongest.

[jyl]

You can still use the cleat idea, just on the inward flanges at the ends of the shelf. I’d screw a horizontal wood board (2x4) to the studs, the wood board should be the length of the shelf’s inside dimension, and the vertical ends of the board relieved just enough for those flanges to slip between the end of the board and the siding. The top surface of the board will support the shelf, the flanges will keep the shelf from coming off the board at the ends, and the shelf’s stiffness will keep the shelf from coming off the board in the middle.

Add a screw or two through each end of the board, to pinch the flange against the siding, to prevent any rattling. Or, bend the outward flange along the top of the shelf just a little, to create friction as the shelf is slid down onto the wood board. Clean look, no exposed fasteners, no drilling your nice shelf, can put shelf not centered on studs without having off-center fasteners showing, and shelf is removable.

Oh, if you put washers between the board and siding, you don’t even need to relieve the board ends.

Oh oh, if you skip both the washers and the relief, but only partially tighten the lag bolts holding board to studs, so that there is a gap that you can slide the shelf flanges into, then finish tightening the lag bolts - now the board holds the flange tight. But the shelf isn’t as easily removed.

That’s it. 2x4 cut to shelf dimension, lag bolts through 2x4 at studs, done.

[jyl]

By the way, do you guys know Hardie (James Hardie PLC) has 90% of the fibercement siding market in the US, and that fibercement is the second most popular siding type after vinyl with about 20% of the total siding market?

[Tobra]

I would mount a wood strip to the studs under the cement board and hang the shelves on that.