huangyhg

hud foundation inspections
anyone have any insight into the practice of dry stacking cmu for manufactured housing piers with respect to the hud permanent foundation manual. i have asked several people in this area (sw virginia) about this. everyone i have talked with that does these evaluaions believes that drystacking is the norm, but as i read the manual (section 503.4), dry stacking is not allowed? any help would be appreciated.
check out our whitepaper library.
it's been about 10 years since i looked at the requirements, but back then, dry stacking was allowed only if the pier was then parged with mortar. in other words, stucco the dry stacked blocks.
you may want to check out the hud requirements to see if dry stacking is permitted and what type of "parging" is required.
a few years ago, it was common to use a surface bonding material (a coating with glass fibers) rather than just a sand cement parge coat.
from an engineering standpoint, dry stacking of masonry has greatly reduced strength, little lateral resistance and highly variable load vertical carrying capacity. - it still may be good enough for some manufactured housing.
the definition of "manufactured housing" by the government has changed through the years in order to be "politically correct" for the purposes of disaster assistance.
dick
as i read in the "guide to permanent foundations":
503-4. masonry piers and walls.
all masonry piers and walls shall have mortared bed and head joints. reinforcing and grouting shall be in accordance with the foundation concept selected from appendix a and designed in appendix c.
the contractor or the seller often makes the arguement (unsuccessfully) that this requirement is silly since dry stacked or not, one shouldn't be counting on getting lateral resistance from the piers.
i'm not too familiar with the requirements, but glancing over the manual it seems that if you have an interior foundation on the home that satisfies appendix c? your exterior wall is non-load bearing. as for load bearing exterior walls, it seems that dry stacking isn't acceptable due to the fact one of the other design methods control.
in the 'state of north carolina regulations for manufactured homes' 2004 edition from the international code council, dry stacked cmu piers are allowed with height restrictions.
tim,
i do a fair number of these certifications for hud loans.
to be blunt, when you identify the foundation type, you always have the option of saying that it is a foundation type "i", (other type, not one of the standard types). i don't have the manual with me, but i am 90% this is the correct designation.
you can then "state" that the foundation meets the "force" requirements of the hud manual and/or local codes.
i will not approve dry stacked piers unless they are used in conjunction with hold-downs (dead men), or the perimeter wall can resist the shear. please note this is in regards to the hud 鈥減ermanent foundation requirements鈥? temporary installations are a different matter.
also, be aware that even here in north east ohio, wind is not always the worst case load. in some areas of very poor soils, i have seen some evidence of dry stacked piers shifting, possibly from minor earthquakes, or just freeze thaw cycles.
also, last time i looked, the program that hud passes out to calculate the forces was not updated to the "newer" seismic values we have in this area.
imengineer1 - where in ne oh? i'm from willoughby.

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]