Manufactured-strapping and piers

I don’t do many manufactured houses and did look through the archives but I still have a couple of questions.

Unit is 1998, relocated to this site 1 year ago and never lived in, well pump was turned off when I got there, Agent turned it on for inspection.

  1. Does the strapping have to be tight (or is some slack acceptable) and does the strapping get connected to the frame or is it OK if it is connected to the exterior/perimeter framing under the siding?

  2. The unit is set on a concrete slab that is not even (level is a different story) I noticed one of the CMU’s as the bottom support had a crack because of a small ridge in the concrete. Due to the crack, the pier is now “flat” to the concrete and should not crack/break any further. Should this be a concern or just note it and move on?

  3. Non pressure treated framing material is used in several areas to “block” the frame, is this a problem.

  4. The manuf. black covering of the joists had moisture/condensation on the underside, there is no venting in the skirting but we have had very high humidity the past few days. Just recommend vent skirting?

  5. The center connection point was nicely spray foam sealed, but had a tag sticking down that said “support pier required at this location” (none was present:roll:) , does anybody know if this would also indicate the necessity for additional ones the length of the unit.

  6. The skirting doesn’t set on the slab all the way around but sets on PT framing in areas where the slab “fell short”.

Not asking for you to write the report, but opinions are appreciated.




Hi Scott first the strapping does not have to be tight is what I have been told, second the skirting does have to be vented, Not all the ones I do have pressure treated on the piers. As far as moisture how damp was the ground was there excessive moisture present, if so was this due to no venting.Ron

If the ground was damp or wet, better drainage and a moisture barrier should be the first line of corrective action.

I can’t tell you what is required in NH but in Florida they take tie downs seriously cause stuff has a way of flying around down here when it gets windy like hurricanes. I would check your State requirements. HUD is the ruling authority for manufactured homes but often the State’s requirements are more strict that HUD’s (their’s being a minimum standard).
Here it requires:

Galvanized anchors (can’t use old mild steel one anymore)

Straps - galvanized and tight, properly number of clips, welds, crimps and other hardware installed. Many old methods no longer allowed.

Proper spacing between anchors and straps
Longitudinal and Laterial stabilization devices or straps

Skirting has to be vented and rodent proof (meaning nothing can crawl through or under it) and braced in back if new and over a certain height

Porches and steps have to be anchored and have proper handrails

Piers (CMUs) have to be installed properly, not leaning, undercut, with base material (ABS pads or concrete pads), double tiered at corners if over 24" high, or over 36" in the center areas.

Midline anchors and straps installed on double and triple wides (along marriage lines)

Tongues and axles removed.

That is just a sample, but again that is Florida, check with your local manufactured home installers and they can usually direct you to the laws or rules governing in your State. You might even attend the school for installers. Oh yeah, in Florida the only person who can sign off a letter on whether the foundation is proper is an Engineer.

Hi Ron,

The pad is a poured slab and I didn’t see any leaks so I am assuming the moisture is due to the humidity and that would be minimized with venting.

With the strapping, does it have to be to the frame, they were also spaced about 10’ apart.


Hi to all

Overall a crap re-siting of a manufactured home and doesn’t meet the manufacturers installation instructions, I’ll bet the home replaced an older model on the same slab.



Actually Gerry, it was relocated to this site, but none the less it is a less than professional job. The sitework wasn’t much better. I bet the guy didn’t spend more than an hour there with his excavator.

Here is a photo of the skirting off the slab and on the PT framing.