HUD PFGMH dry stacked piers

[madcowscarnival]

This is a rehash of previous threads in '08 & '10 regarding dry-stacked piers for manufactured housing installation. Specifically, is there any current, definitive recognition by HUD for using dry-stacked CMU piers over frost depth footings with a proprietary anchoring system (Tiedown Engineering Xi) as part of a permanent foundation? I have been reading through the HUD PATH Guide to Foundation and Support Systems for Manufactured Homes (a newer publication than PFGMH). There are a multitude of statements in the document that identify dry-stacked piers as part of a systems "permanent foundation" classification in both proprietary and non-proprietary systems. My take would be inline with some other commenters that with a manufactured system that controls all wind loading with dry-stacked piers, there would be no need for mortared piers or alternate "surface bonding cement" as there would be no lateral loads resisted by those piers. I've been asked to inspect some proposed sets where the contractor typically installs with no bonding in the piers and the lender who is quite familiar with HUD underwriting, approves them. The lender even showed me some recent HUD-92051 forms with approval, where the set used dry-stacked piers. I have approved these previously (~10 years ago), but made them bond the surface.

I would like to know if there is a way to make a definitive statement of compliance with the dry-stacked that won't be a problem down the road. Any input or experience with this would be appreciated.

PATH manual referenced above:

https://www.huduser.gov/Publications/PDF/foundations_guide.pdf

 

[phamENG]

Based on the HUD "Permanent Foundations Guide for Manufactured Housing (4930.3G)"...no. You have to have mortared bed joints. There might be an exception buried in there somewhere, but 503-4. Masonry Piers and Walls seems pretty definitive.

I believe this has been around for a very long time...it updates the 1989 version and references ASCE 7-93 as the most recent according to the executive summary. But for what it's worth, it's not marked as "Cancelled" or "Being Updated" on the HUD Guidebooks page as several others are.