Double Wide Strapping

[Jim Robinson]

Sanity check here: Two times in a row on a mobile home crawl space inspection I have noted that the strapping is not actually anchored to the earth in any way. I'm not missing something am I? The metal plates are not fastened to the ground. All I am seeing is the straps securing the blocks to the metal beams. If the whole unit blew off the foundation, the blocks would still be secured to the unit but it would all lift as one piece. I have inspected where the metal plates were secured to the earth with anchor bolts, so I know it does happen.

Or, am I not understanding the reason for the strapping?

[Jim Robinson]

Images resized.

[Jerry Peck]

Doesn't look like anything I've ever seen in manufacture's setup engineering. All setup/tie-down engineering I remember while doing code inspections for tie-down and setup specified size and length of auger anchors, and depth of embedment.

Any other type of anchoring (such as to a concrete footing) required local permitting and engineering for the footing, and a special addendum from the manufacturer including that concrete footing as the anchoring foundation.

Of course, though, we have higher winds here, but I doubt that meets manufacturer's requirements.

Do you have the manufacturer's name and the size/model number? An email to the manufacturer will answer your question with the most specific answer.

Such as - if the manufactured home was set up on rock with limited soil covering the rock, those plates shown in the photo may be approved when anchored to the rock in the required way.

That said, there is another issue I see: the straps basically go vertically down, not at an angle down, those vertical straps offer no lateral resistance to horizontal loads (typical wind loading is horizontally). And that 'stretcher' between the two stacks of block? Again go to the manufacturer. Some also required lateral spreaders/stretcher along its length for longitudinal stability.

Just some thoughts based on what I've seen.

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Here is a link to Florida requirements: https://main.putnam-fl.com/wp-content/uploads/2020/05/15C1Finl1.pdf