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andrewcocke 02-06-2008 08:18 PM

Wanting Tips on Jacking a sagging floor beam

My name is Andrew, and I am I live in a 60 year old house that has sagging floors. The house is aprox 30X25 (small foot print), in the center there is one central girder that all the joist connect to. It is comprised of three 2X10's nailed together.

The house is perfectly level in the center and all around. However the house sags in two locations, by the exterior wall on both ends of the girder.

Starting at the exterior wall, the floor slopes about 1" for every 2 feet for about 5 feet, then tapers off and is level for the remainder of the run, on the other side of the girder, the the is a lesser slope, only enough for the basement door to drag when its open all of the way, perhaps 1/2" per 2 feet. I can only figure this is because there is the girder on the one side of the stair well and two screw jacks on the other.

There are two origional 6X6 post in the center of the beam, these post have rotted on the bottom and you can actually move them slightly, I am left to assume they are serving no real purpose at this time.

Who ever lived here before put up a screw jack between the two 6X6 post, almost in the center of the house. I can only assume that this is the only thing supporting that girder at this time.

So let's recap, starting from the basement wall, walk about 8 feet, there is a rotted 6X6, then about 8 more feet, there is a screw jack, then 8 more feet, there is the other rotted 6X6.

Someone told me that it's best to jack a house gradually, over days, maybe weeks or even months if it's very severe.

I read on this website that these screw jacks are not intended to be permanent, I did not know this, and now that I reconsider, this is what I am thinking about doing and I want to know if it's a good idea:

1) The two screw jacks on the right side of the stairwell: I have placed the level on this part of the floor and it's level, no jacking needed there. So I am thinking about wedging in two 6X6's in their place and then taking those two screw jacks out and using them to "gradually" jack up the girder beam by the rotted 6X6's, once the house is pretty well evened out I will replace the old timbers and put in new ones, then remove the screw jacks.

I'm a little weary about jacking the whole house all in one day and replacing the timbers. This would raise the center of the house about 2" I estimate and that in my opinion would be quite a stress on a house that has gradually sunk to it's present position for 60 years. I'm favoring a more gradual approach, but I will confess I have never done this before and was hoping some of the experts could weigh in.

It's not my goal to completely level the floor like a new house, this may cause problems as the house has been remodeled several times over the years and wall panels, trim, etc have been measured to fit a "crooked house". I just really want to take the edge off, and prevent future sagging. I actually retrimmed my bedroom and put up a new closet door 2 years ago, I look to have to redo some of that because I made all my measurements and cut everything to fit a sloped floor. When the floor is level, I speculate that my trim will be lopsided.


Andrew Cocke

andrewcocke 02-06-2008 08:25 PM

One more thing:

What about cinder blocks stacked instead of timbers? Would they hold up better, I plan on living here probably the rest of my life and would rather not have to deal with this again when I'm 70.

Also, this summer I want to frame up a little room down there, to which I planned one of the walls to run underneath about half of the girder and planned to frame the whole room with 2X6's, I can only assume this would offer additional support over the years.

Kingfisher 02-07-2008 11:15 AM

use two 8-12 ton bottle jacks and a 4x4, one by each 6x6. As you lift the wieght off the 6x6 use wedges to place the loan back on them. Just lift a little at a time over a few months. You may still expect some wall and ceiling cracks though. When you are happy with the level replace the 6x6 with new one cut to the full size and fasten in place.

andrewcocke 02-10-2008 01:05 PM

Thanks for the reply. It's been a gradual process. As it stands, I already have one door that wont close now. I will go a little more, but as I stated, things are so far out of level its not my goal to make it perfect, really I just want to prevent further sagging.

The old timbers have been knocked out now. But don't panic, they weren't being used anyway, and I discovered once I removed them, they weren't even touching to footer anyway. They were actually in a hole in the basement floor about 5". However the whole bottom of the post was just rotten wood. The house was holding the timber up, not the other way around.

This means for the 5 years I have lived here, the whole center of gravity of this home was been resting on one solitary screw jack. Scary.

The good news is the problem is being rectified.

justdon 02-10-2008 02:12 PM

Are you sure they rotted off,,,or termites ate the bottoms off?

I would be tempted to replace those with solid large diameter heavy wall pipe,,,it doesnt rot off,,,with large heavy steel plates both top and bottom.

OR I see NO problem in a house as small as yours with leaving the screw jacks in there,,,you can always give them a turn or two IF needed another day!!

Were there any piers or footings under those 6X6 posts?? Did they sink thru floor just based on weight??IF you decide to go back to wood support,,,suggest a concrete pier so wood is 4-6" ABOVE floor level so moisture cant accumulate OR contribute to a further failure.

If It were "I" doing this,,,I think I would jack slowly to perfect level,,,then repair or redo any needed items,,,because in the long run YOU will be happier and MORE satisfied than with your 'marble' floors.(MY term for them)

What you say are marble floors??? Kids play marbles on their bedroom floor,,,when they take their hand off them the marbles all roll into the closet,,,a self room cleaning effect!!!

Have FUN with the house,whatever you do!!! Resale WILL be higher on a straight house vs a crooked one!!Even YOUR estate sale!! Living there forever sounds like a GREAT plan to ME!!!

andrewcocke 02-10-2008 08:24 PM

Well, my first thought was termites, however in order to get the old post out, I actually cut them about 5" above the floor line so I could beat them out of their hole.

When I looked at this cut from the inside, the timber was actually in good shape. I didn't see any termite evidence in the post even as far as 5" up the. The basement used to leak quite badly until I sealed it up a bit. I can only assume that water got down inside of the hole and rotted it. The timbers don't look as though they were treated, and wood seems soft, like pine, so it wouldn't have taken much to rot. Also, the timber that was near the point of leaking was in much worse shape than the other. It is for this reason I don't favor placing the new post in the old hole, if it ever gets wet again, the water will just seep in the hole and there is no way to dry it out.

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