yep sounded like pipes were in way, and as far as thickness heavier is always better, who cares its cheap and extra thickness shouldnt matter.
and yeah i had this problem at home sale time, the home inspector went nuts, required jack posts, but just on floor, not on a footer.
what a waste in my case the joist hadnt sagged, and 50 years was a long test...
I realized something nice, which is that I can probably sister the joist, with a 2x10 behind it. The plumbing would have to be gotten out of the way first but I'm almost sure the plumber can redo it so it's not in the way of a sister.
I talked to a home inspector and he said that while attaching angles would work, it would look amateurish and might be an issue for a home buyer. I think he has a point - you want something that not only works, but *looks* like it works, and sistering the joist would definitely look like it's been fixed.
Yes, a jack post sounds much better than brutally trying to reshape my weak, ailing joist with a 2x4 and a hammer :)
thanks for the help, Laura
I realized something nice, which is that I can probably sister the joist, with a 2x10 behind it. The plumbing would have to be gotten out of the way first but I'm almost sure the plumber can redo it so it's not in the way of a sister.
I talked to a home inspector and he said that while attaching angles would work, it would look amateurish and might be an issue for a home buyer. I think he has a point - you want something that not only works, but *looks* like it works, and sistering the joist would definitely look like it's been fixed.
Yes, a jack post sounds much better than brutally trying to reshape my weak, ailing joist with a 2x4 and a hammer :)
thanks for the help, Laura
Lowe's has a "steel adjustable building column" that they tell me will work for jacking a joist up a small distance. See
Does it actually work as a jack? It has a small rod through it at the top that turns a screw to raise and lower the top plate (not shown in the picture). But that may not have enough leverage to actually jack up a joist.
Is this what you're talking about?
Also, should I attach plywood plates to the top and bottom for safety? It would be resting either on my concrete garage floor or on some paving stones that are on the floor. The metal plates it comes with are about
4-6" square. Does one need to use a plumb bob or something to make sure it's vertical?thanks Laura
However, the sister wouldn't extend the full 15' length of the joist. It would go about 2 feet - or whatever - past the cut part of the joist, and the other end would rest on the sill plate. Does this seem like a strong enough fix?
Laura
Uh, no, not plywood plates. Big honkin' steel plates. If you must use wood, use real wood at least a couple inches thick and a couple feet long on the bottom. On the top, you want something that will keep the post in position. And no, that dinky little handle on the Lowes post will not provide enough leverage to do anything. What those are, are adjustable posts, not jacks, meant to be left in place once the offending beam is jacked into place and set back down on them. Try local rental place, and see if they have proper jacks available on a weekly or monthly basis at a decent price. Once the floor is all lined up, you can figure out how to add structure to keep it that way. A common method is to add a small beam between two of those adjustable posts, buried in adjoining walls, or at least out of the way. Beam can be steel, or a tripled 2x8 or whatever. But it is a lot more elegant if you can figure a way to do it within the floor system itself, by sistering joists or adding box sections or whatever.
Note that any permanent posts you add should have footings under them, if there are other loads being carried down to them by the house above.
What you have is a very common problem, and the cures are usually hillbilly at best. Framers always cringe when they see a plumber carry in a sawzall. Stuff like this should be addressed in the design phase- if they know a bathroom is going above, make sure there is a path for the pipes. Either make tub centerline land on a joist bay, or header off an opening below the wet wall.
Oh, do you mean like I said in the first reply in this thread? Who woulda thunk it? ;)
There are more serious problems with the bolted on angles solution than the appearance, but your home inspector is right. It will look like a kludged repair. A major problem with the bolted angle repair is that it concentrates all of the load at the few attachment points at the very bottom of the joist. Joists tend to unzip along the grain in that situation. Such repairs also creep more over time and they bounce more than a sistered joist. These are very bad things in a tiled bathroom.
There are many issues with repairing a seriously compromised joist in a bathroom, but first and foremost is making the place structurally sound. If it's necessary to sister the joists on either side of the compromised joist and install a header to pick up the load from the compromised joist (which would be cut back to allow the plumbing to run where necessary), it's a lot more work, but then that's what you do. I suggested a simple sistered repair on just the compromised joist as I don't know anything more about your bathroom layout, loads, plans for tile/stone, whatever.
Yep. Either way works. If you build temp shoring out of wood, just use a plate at top and bottom, install opposing 2x4s at an angle so they're touching at the point where you want to jack up, and their bottoms are spread a foot and a half apart, then alternately bang the bottoms together along the plate. Just hit each enough to loosen the other one, then switch to the loose one until it's jacked up where you need it.
R
That is EXACTLY what I was recommending. They DO work - very well in fact.
I would put a 1 foot square of 1 inch plywood on the floor to spread the load a bit, and either eyeball it in reference to 2 known plumb surfaces or true it wirh my level. Depending what the top of the jackpost has, I might put a plywood or 2X4 block under the joist - with cleats to hold it centered under the joist and to hold the jackpost centered under the joist, if there was any question about the post possibly slipping off the joist.
I'd sister about 6 feet. Less chance of the joint between the damaged and sister joints failing over the longer distance, and it will look "substantial" to anyone checking in the future. For the small extra cost of lumber and nails/screws involved.
That's what I meant too. I don't know why so many webpages don't call things what people call them. I coudn't figure out what Home Depot calls them, even though I know they sell them too.
**One example is the cube tap. Actually I don't know what people call them either, the small things one plugs into an electrical outlet, then plugs three thrings into it.How long is it? I dont' see that in the picture, and I thought one is supposed to provide his own jack handle or other 18" or 2 foot heavy steel rod to turn it with. Maybe grease the threads first if they're not greased???
This is your first post in the thread. She was only trying to lift up her bathroom floor and hold up her bathtub. Do you really think she needs steel plates?
Tripled 2x8's!!!. This is only to supplement** one notched joist. It's not going to hold up other joists.
**Temnporarily I think it was so she can take the stress off the joist and lifte it 1/4" iirc until she can sisters in a steel plate or one on both sides.Now footings you want!! YOu must not have read the thread. :)
I thought she was saying there is no room to go 6 feet, only 2.
In that case, or in any case, the holes should be drilled so they are smaller than the screws, OR, iiuc bolts may be used with shallow threads. I presume there are drills not a bit bigger than the size of the bolts, because leeway there is what gets magnified if the sister is only 2 feet long.
BTW, since you first posted OP, I've tried engraving water, but it all just rushes back together again. Is there a trick to it?
The OP is not jacking up a load bearing wall, and if the adjustable post has a 1" 10tpi thread like the 4 in my basement they WILL do a lot of lifting. If they are 10tpi, they will lift 1/10 inch per turn of the screw. If you use a 1 foot long handle to turn the screw, you get a theoretical mechanical advantage of 753 to one, so 50 lbs of force(50 ft lbs) would lift 37,650 lbs without taking friction into account. With well lubricated threads you are looking at something close to FIFTEEN TONS lifting force at 50 ft lbs of torque. Using a 2 foot long bar to turn the screw, it is VERY easy to input 50 ft lbs of torque. The posts are rated for about 12000 lb at full height.(which is less than 25 ft lbs of input force, by my calculations.
My numbers may be off - but even if I am optiminstic by 100%, the capability of the post to handle the job is NOT in question.
I've used them for a lot worse jacking issues than what is presented here - with excellent results.
As for the plywood - all you are doing is spreading (at full rated load of, let's say 12000 lbs) a load of (on 8" square plate) 187 lb per sqare inch over 1 square foot (assuming a 12" square peice of 1" plywood) for a resulting load on the garage floor of 85 lb per square inch. I don't have the numbers as far as the compressive strength of plywood at hand - but 1 inch fir ply is easily up to the task - don't know if I'd trust it on loose or copacted soil - but definitely on concrete.
My suspicion is well under 2 tons of lifting force would be more than adequate for the job at hand. Childs play with that "adjustable post".
On the same page that you linked us to are items called "steel floor jacks", so there is obviously a difference between a "steel adjustable building column" and a "steel floor jack".
re: "That's what I meant too. I don't know why so many webpages don't call things what people call them."
Maybe because there's a difference between an "adjustable building column" and a "jack post"?
I've used the "adjustable column" to slowly bring a floor back to level at my brother's older home. Raised it about an inch over 6 months - and that was under a wall in a 2 1/2 story roughly 90 year old brick house. Same problem - someone had cut a floor joist and it sagged. These were "adjustable columns" - not jack posts. The jack post is a heavier device and is usually used to get a beam up to where it belongs to put either fixed posts or a block wall under it - I've used them jacking up a barn too. A bit too heavy for the "adjustable post" to even act as a post -
My point was more about what they are called vs. what one might use them for.
When mm said "I don't know why so many webpages don't call things what people call them." I assumed (yep, there's that word!) that he meant that "so many webpages" were calling 'jack posts' 'adjustable columns' as if they were the same thing.
My response was that they are calling them by different names because they are different items.
I'm glad to hear that. I called the manufacturer and they told me the adjustable column would work for jack>> I realized something nice, which is that I can probably sister the joist,
That's why it's useful to talk things over, it gets you to re-think things. I can extend a sister past the cut easily about 27". Past that I start running into stuff that would make it very difficult, like the toilet drain pipe and pipe hangers. I think I'll attach angle on the front side of the joist, too. And yes I can drill pilot holes that are slightly too small for the screws, so the screws are really tight.
Laura
I have one ot the other holding up a ceiling I-beam in my basement.
I think there's another I-beam only 10 or 11 feet farther back (in my
22x36 townhouse, but it's sheet-rocked in. At the foot of the basement stairs, there might be another post or column beneath it, but it's boxed in and I'm not sure.
FWIW I meant various things. It seems it's not even this thing, which it seems are two different things, but ... well, if it ever did my memory no longer recalls things on this basis, but I know I've seen a bunch of things labeled in the store or in a catalog or webpage with terms on one I know uses. The cube tap is the only thing that comes close.
I talked to my plumber this morning and he said yes, they can change the plumbing so there would only be a single pipe penetration through the joist for the bathtub drain pipe. (his assistant plumber thought they couldn't). So, I can also strengthen the joist with a metal plate bolted onto it.
Someone told me there's standard hardware, metal plates to strengthen joists. Could someone point me to it? I want something that would please a building inspector ...
I'm also planning to sister the cut area with a 2x10 on the back. The plumber said they can also do the drain plumbing so the sister wouldn't have to be cut.
So it should be good and strong that way :)
Laura
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