mounting panels to treated-wood frame

[bob-n]

RShackleford,

You clearly know construction and will have no trouble doing it. This tip will be unnecessary, but I'll share it anyway. Please don't take offense.

For those long lag bolts, an impact driver will come in very handy, even for pre-drilled holes. I tried a conventional, decent-quality Ridgid driver and it couldn't put the bolts all the way in. A friend loaned me his Milwaulkee impact driver and it installed the bolts effortlessly.

[littleharbor]

Not sure if this will be helpful or just throwing a wrench into the works. After 6 pages of comments I figured, why not?

We have lots of winds here in Baja and even Hurricane Rosa passed right over us last year. I was concerned with the wind getting under my array and built this dog eared cedar "wind break" to decrease the uplift on my array. 4 years have passed without any perceivable problems.
DSCN4732.JPG

[J.P.M.]

Not sure if this will be helpful or just throwing a wrench into the works. After 6 pages of comments I figured, why not?

We have lots of winds here in Baja and even Hurricane Rosa passed right over us last year. I was concerned with the wind getting under my array and built this dog eared cedar "wind break" to decrease the uplift on my array. 4 years have passed without any perceivable problems.
DSCN4732.JPG

Probably decreased uplift on the array a fair amount but I suspect the addition didn't eliminate as much of the uplift as you might think.

For starters, most winds probably aren't normal to the rear of the array. Those from a non oblique angle, but still from behind the array, will result in some uplift. Then, there's the venturi effect "sucking" at the front of the array. Not all uplift is from wind force "pushing" against the back of the array. Depending on wind direction, you will also see some compressive loading in the array supports that are parallel to (in the plane of) the panels, increased compressive loading and shear at the array anchorages at the front and some uplift where the fence attaches to the roof. Just sayin'. Did you run any calcs ?

[RShackleford]

We have lots of winds here in Baja and even Hurricane Rosa passed right over us last year. I was concerned with the wind getting under my array and built this dog eared cedar "wind break" to decrease the uplift on my array. 4 years have passed without any perceivable problems.

How are your panels mounted ? Turnkey metal racking system, or something more adhoc like I'm doing ?

[littleharbor]

Probably decreased uplift on the array a fair amount but I suspect the addition didn't eliminate as much of the uplift as you might think.

For starters, most winds probably aren't normal to the rear of the array. Those from a non oblique angle, but still from behind the array, will result in some uplift. Then, there's the venturi effect "sucking" at the front of the array. Not all uplift is from wind force "pushing" against the back of the array. Depending on wind direction, you will also see some compressive loading in the array supports that are parallel to (in the plane of) the panels, increased compressive loading and shear at the array anchorages at the front and some uplift where the fence attaches to the roof. Just sayin'. Did you run any calcs ?

I wouldn't know how to run calcs. Besides some wind protection I put up this fencing for aesthetic reasons.

[littleharbor]

How are your panels mounted ? Turnkey metal racking system, or something more adhoc like I'm doing ?

I used some old used Pro Solar racking. If you look closely at the top1/3 of the racking you'll see I added some inverted racking that allowed me to adjust the tilt of the array. I never ended up adjusting the array tilt being that I never seemed to need to. Now that I added the fencing the panels are no longer adjustable.

[RShackleford]

RShackleford,
For those long lag bolts, an impact driver will come in very handy, even for pre-drilled holes.

Yeah, I think I've seen tradesmen use those to great effect. Impact driver is different thing than hammer drill right ?

[Mike90250]

Impact driver is rotating impacts, like tire shops use to remove lug nuts.
hammer drill is axial (for rock or concrete, the impact breaks the rock, the rotation clears it away - think of John Henry, and his shaker, who rotated the drill between blows)

[bcroe]

Yeah, I think I've seen tradesmen use those to great effect. Impact driver is different thing than hammer drill right ?

Mine has different settings for hammer or drill. Bruce Roe

[RShackleford]

John Henry, and his shaker, who rotated the drill between blows)

John Henry was a steel-driving bastard
But John Henry was a bastard just the same
And an engine never thinks about his daddy
And an engine never needs to write its name.

[Mike90250]

trivia:

A shaker also called a turner, was a nervy navvy who held the drill and turned it slightly after each blow, giving it a little shake to flip the rock dust out of the hole. The heat tempered steel available in those days dulled after a few minutes at most, and the shaker had to snatch it out of the hole and insert another between hammer strokes.

Consider then how trusting was Phil Henderson, or Little Bill, as John Henry's shaker has been variously called, who turned John Henry's steel while lying on his back holding it between his legs, or by standing against the rock face holding it crooked in his arm, or holding it close to his body (depending upon whether the drill was being driven down or sideways or up), with the hammer flashing by his groin or rib cage or his face.

As the drills dulled, the shaker blindly held out his hand to the "walker" (who walked the worn steels to a blacksmith at the portal and returned with reforged one), like a busy surgeon taking a scalpel from a nurse, to grasp the new drill. So fast were drills used up that most of the men and boys employed in tunnels were walkers. On a big project the drillers could use up thousands of steels a day. In some cases the drills were weighed, and the driller was docked for the weight of steel that was worn off the points, a weird work incentive.

[RShackleford]

trivia:
A shaker also called a turner ...

I only operated a jackhammer once, briefly, while doing landscape work while in grad school. Wouldn't want to do it again.

Lyric I quoted was Jason Isbell; great song. The Dead have one too: "Been balling a shiny black steel jackhammer ...".

[RShackleford]

I've mentioned my site is a bit sheltered, by trees mostly on the north side. A little anecdote ... the other day we had severe thunderstorm warnings, sustained 30mph winds and gusts to 55mph or more; at my house, I'd say we saw something close to that. I'd just cut up a couple of oak trees that fell in my neighbors yard, and made a stack of big logs for cutting up next winter (when I start refilling my firewood FIFO). To keep 'em dry, I covered the pile with some scraps of metal roofing lying about; about a 12ft x 8ft covering. Worried about the storm, I weighed it down with some scrap treated lumber - two 2x6s, two 4x4s, and a 20ft extension ladder (un-extended). I'm gonna say maybe 150# of stuff, tops. It didn't even think about blowing away.

Like I've said before, my installation is going to be demolished by falling trees, long before it blows away.
ADDENDUM: To which, when he came to inspect my wood support frame, the building inspector agreed.

[SunEagle]

Got the wooden frame built and so far it's holding up well. I'd like to upload a picture, but keep getting "Error uploading image".

The picture needs to be sized smaller. Sometime Paint can be used to do that. If not the bit size is too big for the upload.

[RShackleford]

Here's a picture of my completed wooden frame (still holding up nicely ) with the "L feet" installed.

framing and l-feet small.jpg

P.S. The L-foot is a beefy aluminum bracket that holds the IronRidge rail to wood to which it's attached using a lag bolt. It was designed to be attached to the rafters of a house, but I'm using it to attach to my treated wood frame. I hope it's strong enough. It's definitely the weak point, as the aluminum rails and wooden frame are definitely strong enough. I've done computations for the holding power of the lag bolt (556 lb). But it feels like the square head of the bolt that connects the rail to the L-foot is weaker than the lag bolt. It's not fair to compare this to a roof-mount system, because it's obviously far more exposed to wind uplift. But a ground-mount system attaches the rail with this same square-head bolt (but to a bracket that bolts to the steel pipe foundation). That bracket uses two square-head bolts to attach to the rail, whereas the L-foot only uses one. However, a system using that bracket works up to 170mph and wind exposure "D". I feel like that's easily good for a factor of two over my 115mph w/ exposure "B" criterion. I thought of putting two L-feet at each corner of my array, and I have the materials, but I doubt I'll bother.

Sharp eyes will note the lack of any diagonal bracing against rotation about the vertical axis (not sure of the correct PE way to put this). Talked it over with inspector, who felt it unnecessary. The four walls are braced to be very rigid, and they're tied together at the corners.