From: John De Armond
Subject: Re: Barn walls bowing
Date: Fri, 05 Aug 2005 11:42:23 -0400
On 5 Aug 2005 13:01:03 GMT, ak977@FreeNet.Carleton.CA (Jonathan Mau)
>I have a small barn about 24 by 40 feet. It is the type that is sunk into
>the side of a hill such that both levels can be accessed from grade. I
>think there is a word for this type of barn, but I digress. The
>foundation wall is concrete block. The building is circa 1972.
>The 3 walls that are below grade are bowing, about 3 inches at a guess. I
>imagine that these walls have rebar in them so a sudden failure is
>unlikely, but I am somewhat worried.
I'd be surprised to find any sort of vertical rebar in the blocks.
Sometimes wire is laid in the horz mortar lines but seldom is rebar
driven through blocks. I've seen several situations such as yours.
The walls bulge a bit and then there is a catastrophic failure as the
edge load on the blocks fractures them. The result is usually a
basement (or whatever) full of mud.
>I am inclined to get out my jack posts and build a small tower or truss
>and using the truss against a jack post push the walls plumb again a 1/4
>inch a month or so like one would do if one were levelling a floor. Then
>perhaps pour some short wall sections perpendicular to the walls to keep
>them in place in the future.
That is probably doable. You'd need to build buttresses inside after
straightening. I'd probably want to get at the root cause of the
bulge, however. Is it hydraulic or just shifting dirt? Is the bulge
recent or the sum of creepage over the life of the building? Is there
something making it suddenly worse?
FWIW, I saw a small bulge developing in the basement wall of my cabin
years ago. Mine was hydraulic-based. Based on a PE's engineering
advice, I had the foundation excavated and a french drain system
installed. Problem solved, plus my basement finally dried out. My
neighbor had the same problem, ignored it and had a catastrophic
failure. The back of his cabin drooped when the foundational support
dropped, doing major damage.