Replies

1. 
   woodguy99 | Mar 17, 2005 12:39am | #1

   Hammer, first off, welcome to the board. 

   Now, to try to answer your question.  BTW, a lally is specifically a concrete-filled steel column.  A jackpost is a jackpost, doesn't support as much weight, and is indicative of an afterthought or quick fix.  A 4x4 beam is also pretty small to be doing much good.  Someone probably felt like the floor trusses had too much bounce or deflection after the floor was built, and threw in the 4x4 to take out some bounce, maybe just before the sale.  There is most likely no proper footing under the jackposts.  An 8x8 doesn't count as a proper footer.

   Ideally you should dig out proper footers, something like 30" square x 8 or 12" deep, set real concrete-filled lallies on the footers, build a new beam out of more substantial material, and secure the top of the lally with lally plates, pieces of steel designed for the purpose.  For very heavy loads Springfield manufacturing makes some heavy-duty plates.

   There may be some serious weight and logistics issues going on here; what is your experience level and your committment to doing it right?

    

   Mike

2. 
   DanH | Mar 17, 2005 12:57am | #2

   You've got basically two concerns:

   1) Can the structure above and below the post stand up to the force of the post?

   2) Is the post in any danger of disconnecting itself from the structure (due, eg, to a beam twisting sideways, etc)?

   There's nothing wrong with the post being on a piece of (treated) wood at the bottom to spread the load slightly and provide a little "give", but if the post is exerting a lot of force (I'm guessing more than about 1000 lb, if on a concrete basement floor) then it needs to have a proper footing cut into the floor. (Obviously, in a dirt crawlspace you need a proper footer regardless.)

   And, at the top, any "spreader" the post is bearing on to transfer the force across multiple joists, etc, needs to be similarly strong enough. Generally a 4x4 isn't going to hack it for more than a few hundred pounds of fource. Even if it is strong enough to not snap, it will bow over time. And, aside from that, it needs to be sufficiently anchored to assure it won't roll if one edge crumbles, etc.

   Needless to say, the post should be attached (with nails/screws/etc) to the structure at the top, and preferably at the bottom.

   
   

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   Edited 3/16/2005 5:59 pm ET by DanH

1. 
   RenaissanceRestorations | Mar 17, 2005 01:22am | #3

   Last time I replaced 12 wooden tree trunk style posts in an 1880's house, I used 24x24x12 concrete footings for each post. Used 4" cement filled lolly columns, with 1/4" base plate, spot welded to the base of the post. The top of the post was fastened to the carrying beam with a custom made "U" saddle to straddle the beam, and was likewise welded. I've was told by the assistant building inspector in that town that I went "overboard", but it's better that way IMHO.Renaissance RestorationsAntique & Victorian Home Restoration Serviceshttp://www.renaissancerestorations.com

1. 
   hammerheadxx | Mar 17, 2005 04:35am | #4

   Thanks for the input.

   Havent purchased yet, wanted to know what I was looking at.  Basically the foundation is on rock, the 8x8 timber is laying on bedrock/dirt.  NO footing.  There is little or no bounce in the floor above.  The 4x4 is slightly bowed.

   Looked like a Jackleg job to me.  For a few more bucks and a couple hours it could have been done right.  Wonder what it would cost to have someone come fix the "repair".

   I see a lot of this kind of stuff here.  Not too worried about the structural integrity, more worried about it meeting codes or getting hammered by an inspector when I go to sell.