# Screw jacks and my 2nd story porch. Help



## zoso (Oct 7, 2005)

I have rot at the base of a support for a 2nd story porch, and another above that one.How do I raise the structure, support it and put in a block to replace the rot? Are there better methods?


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## RobertCDF (Aug 18, 2005)

I use 2x4 or 2x6 and make a T post |-- and use a bottle jack.


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## jproffer (Feb 19, 2005)

Mike, what are you talking about? Being on this forum and not the other side, we have to assume he is some sort of contractor, or at very least has some knowledge/skill in the trades. This is not that complicated a job. Jack up one post at a time, cut out the bad one, put in the new one, let it down. It's not that hard, nor is it that dangerous if you use a little common sense, such as:

- Don't remove all posts at once. Even rotton, they're holding SOMETHING...let them do that until you're ready to change them.

- Don't get carried away with the jack. Just enough to get out the old and get in the new, that's it. Ya don't have to raise it 3 ft. off the post. Half an inch is plenty usually.


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## jproffer (Feb 19, 2005)

You should assume that neither of them is going to fly at all....anyone with a brain (with or without trade skill/knowledge) can jack up a porch 1/2" and change a post. We're not talkin' brain surgery here.


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## wasdifferent (Dec 18, 2004)

jproffer said:


> You should assume that neither of them is going to fly at all....anyone with a brain (with or without trade skill/knowledge) can jack up a porch 1/2" and change a post. We're not talkin' brain surgery here.


Sorry, I'm new at this. Do you have any more instructions for me on what to assume? What should I assume about Euler's column formula? What should I assume the porch weighs? What should I assume the length of the column is? What assumptions should I make about how well the porch is attached to the house? Should I assume that there aren't any other rotted structural members?


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## jproffer (Feb 19, 2005)

What I MEANT by my original post was that since he is, in fact, in contractortalk and not diychatroom, we could assume that he is some sort of contractor (which were almost my exact words). SOOOOOOOOOOO....assuming that he IS some sort of contractor, this should be no problem. 

Do I know what happens if he gets a full load on the T frame and it's not plumb? Yes obviously I do as I know you do also. 

Should anyone who gives it about 2 seconds of thought realize this too? They should...maybe they won't, but they should. (see this is where the common sense part comes in)

We're not talking about jacking up a house. It's a porch for God's sake. It don't weigh that much.


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## wasdifferent (Dec 18, 2004)

jproffer said:


> ...maybe they won't...


That's only one of the reasons why they should hire a qualified contractor. There is NO WAY that I would offer advice on this one without a site visit. There are just too many things that could go wrong.


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## jproffer (Feb 19, 2005)

Zoso, screw jacks would be better (safer...less pieces to come apart), but a bottle and a T-frame would work too. 

- Make sure to keep the T-frame in line with the jack (which is to say...as plumb as you can get it.) As was said, if it's off by much it could kick out. 
- Have a helper. It's difficult (to say the least) to hold a brace plumb, operate the jack, watch the top of the post for clearance, etc. by yourself. 
- Put the new post close to it's final resting place before removing the old one. Just a precaution which may be unnecesary, but ya never know. IF the jack would kick out, it would hold the roof enough to get the rig back under it and raise it up again. BTW, it won't come SHOOTING out even if it does kick out. If you were raising your whole house, then yes...a porch roof, no.
- Have everything in place before raising each section, so as to have as little "on the jack" time as possible.
- Any questions come back and ask before the job, not during.

Like I said, common sense. It's not rocket science but think it through. Every detail counts.


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## wasdifferent (Dec 18, 2004)

The total absence of all of the most important information in the original question leads me to ASSUME that zoso should have someone more experienced ON THE SITE. This lead me to SAY that zoso should hire a qualified contractor. If it's an easy job, then it shouldn't cost much. If it is a dangerous or difficult job, then it's worth the money to hire a pro. I hire professional trade contractors every day, they are well worth the money. 

Plumbing the temporary column is not the problem here. No matter how carefully it is plumbed, any flexure in the column what-so-ever will push it out of plumb. That is what Euler's column formula is all about. The column here is a two piece system with a hinge in it, that's not how we design columns. It is unstable by it's very nature. Once the column is out of plumb, it's too late, you have lost control of the situation, and your fate is out of your hands.

Also, one needs to look at the STABILITY OF THE ENTIRE SYSTEM (structure), not just the stability of one piece of falsework. The fact that no one has mentioned this is more than a little disconcerting. 

IMHO, giving someone advice on a job like this without a site visit is poor judgement.


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## RobertCDF (Aug 18, 2005)

Ok lets try to be really safe here. Build the post and put it on the jack and jack it up enough that the post stays but is not yet supporting any real weight. Then nail blocks on both sides of the post and to the beam you are jacking up. Then add 4 braces to the T post and nail them to something sturdy. Then put a 2x12 block on level ground next to the old post. Build another T post just a 1/2" longer then the distance from the beam to the 2x12 block. Then jack the beam up 1/2" add the other T post under the block and add 4 more braces nailed to something sturdy. Then remove old post and replace with new one. Then raise the jack 1/8" to take out other temp T post. Now lower jack and remove jacking T post. Move on to the next post and repeat. Start at the tallest post so you can just cut your T posts shorter. Now I would never go through this much trouble but just to make some people on this forum happy about saftey this should keep just about anything from happening. And by the way I am a professional contractor if you called me I would do exactly what I said in my first response.


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## jproffer (Feb 19, 2005)

> And by the way I am a professional contractor if you called me I would do exactly what I said in my first response.


So am I....and so would I.



> Build the post and put it on the jack and jack it up enough that the post stays but is not yet supporting any real weight. Then nail blocks on both sides of the post and to the beam you are jacking up. Then add 4 braces to the T post and nail them to something sturdy. Then put a 2x12 block on level ground next to the old post. Build another T post just a 1/2" longer then the distance from the beam to the 2x12 block. Then jack the beam up 1/2" add the other T post under the block and add 4 more braces nailed to something sturdy. Then remove old post and replace with new one. Then raise the jack 1/8" to take out other temp T post. Now lower jack and remove jacking T post. Move on to the next post and repeat. Start at the tallest post so you can just cut your T posts shorter. Now I would never go through this much trouble but just to make some people on this forum happy about saftey this should keep just about anything from happening.


Noone I've ever met would go to all that trouble to lift a porch (and you wouldn't either I see)....I know I keep saying this, but others keep acting like it's not true...it's a porch roof, that's ALL. 



Mike, try to forget about just this one thread for a second and try to think more generally about projects, homeowners, Diy'ers and the like. While I may agree that this particular OP may be a DIY'er, a lot of the time, people don't hire such jobs done because contractors get too self righteous to even bother with such a small job. OR, they tell Mr. and Mrs. Small Job, "I'll try to work it in as soon as I can", which means "When all my good paying jobs are done, I'll use you as filler until the next big job starts. I may get all of the posts changed or I may only get to one at a time, but you'll put up with it because I'm the only contractor out of 10 that has even said that I MIGHT get to it sometime." So Mr. and Mrs. Small Job get tired of waiting and come on a board such as this one and ask advice for the best way to get it done. So now, they've been down the "call a professional" road and it's a dead end. Do you think it's better to caution them as much as possible while still giving them the advice they need, or just bull up, say "hire a pro" and thats it? They have already tried to hire someone to no avail. They basically come on here saying "I've tried the pro thing, it didn't work, I'm GOING to do it myself with or without your help" Don't you think we have a responsibility to try to lead them in the right direction AND at the same time, warn against any possible dangers? I tend to think that of these two options:

1) Let them go off blindly into remodeling land and hope for the best

or

2) Let them take the many viewpoints they find on here, including yours, and make an INFORMED decision.

Option 2 is the better of them.


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## RobertCDF (Aug 18, 2005)

I think mike may be mad becuase this person may live in the same town and he wants to give them a $10,000 bid to replace 3 posts. So therefore does not want them to relized that it is an easy job. I bet mike would sugjest 1 crane for each post rig them all up have them hold it in place and replace the posts. BTW I have had posts slip out from under a jack a few times. The reason 1. I had not leveled the ground enough 2. the post was not plumb. But in these few times the jack always tipped while I was jacking. I have NEVER had one move once it was supporting anything.


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## jproffer (Feb 19, 2005)

> BTW I have had posts slip out from under a jack a few times. The reason 1. I had not leveled the ground enough 2. the post was not plumb. But in these few times the jack always tipped while I was jacking. I have NEVER had one move once it was supporting anything.


Ditto. And it wasn't a "projectile" either (at least not the ones that were under the HUGE load of a porch roof:cheesygri ), it just...kinda....fell over, and since I had taken the precautions listed above, that's all that happened. The roof didn't cave in, if you can believe that. I kinda doubt that a porch roof would fall anyway, for several reasons. 

1) There's just not enough weight there.
2) The rafters are tied to the wall of the house
and 3) There are usually 3 or more other posts that are still under it.

OK for the sake of Mike's nerves: Zoso, where do you live? If you're close I'll come by and do it. Two guys is $75/hour and it shouldn't take more than 2 hours, start to finish. I'll throw the first coat of paint on the new posts for nothin', whad'ya say?:thumbsup:


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## PipeGuy (Oct 8, 2004)

pitterpat said:


> This an advice forum...


It's really not. IMO, the fact that you have such a notion is really quite revealing.


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## jproffer (Feb 19, 2005)

I'll agree there Pipe. This is indeed a contractors forum, but in-as-much as he was already here, I figured, what's the harm. (If you check his profile it says he is a fence contractor, btw)


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## PipeGuy (Oct 8, 2004)

jproffer said:


> Being on this forum and not the other side, we have to assume he is some sort of contractor, or at very least has some knowledge/skill...


There's an accident waiting to happen if I ever saw one. Let's all assume that only 'contractors' can get in here and ask questions.
How professional is it to offer 'how to' advice, site unseen, to someone who's posted here all of 10 times. Take the time to at least click your mouse a couple of times JP and look at zoso's history before you start making ASSumptions like that. If you do, I think you'll have a different take on the guy's skill level.

Not only that, the guy plainly noted that he's want to shore up a...



zoso said:


> ...2nd story porch, and another above that one.


I think I smell the video for another Vonage commercial in the making.


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## 6stringmason (May 20, 2005)

woo woo..woo woo woo


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## Cole (Aug 27, 2004)

The most important thing is too use common sense.


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## jproffer (Feb 19, 2005)

Which I believe I said right off the bat:cheesygri 

Thanks Cole...and BTW, I just kinda got rubbed wrong...but if you honestly see reason to close it, then do so. I just don't, that's all.:thumbsup:


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## Cole (Aug 27, 2004)

It stays open as long as all posts retain to helping him out with his questions.


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## Teetorbilt (Feb 12, 2004)

I raised a 40 X 8 ft. porch/roof almost 6" about 2yrs. ago with jackscrews. There was never a time that I considered any phase of the project hazardous except to the structure. It was raised 1/4" twice ea. day which I consider fast, the porch didn't bother me but the roof trusses did.

The 6x6 posts were dadoed to accept 1/2 of the 4X8 header and were through bolted. The screwjacks were placed 4ft. to either side of the post to allow for new foundation work.

I'm an engineer and the project was lightweight, you should consult a local one to appraise your situation.


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## wasdifferent (Dec 18, 2004)

RobertCDF said:


> I think mike may be mad becuase this person may live in the same town and he wants to give them a $10,000 bid to replace 3 posts. So therefore does not want them to relized that it is an easy job. I bet mike would sugjest 1 crane for each post rig them all up have them hold it in place and replace the posts.


Actually Mike wouldn't know how much to bid, or which method he would use, because he hasn't seen the job yet. There are porches, and then there are porches. I'm not ready to make any assumptions yet. 

BTW capitalism is still legal in America, and I expect to get paid a fair amount for my knowledge, my experience, my hard work, and my sound judgement. 




RobertCDF said:


> ...BTW I have had posts slip out from under a jack a few times...





Pipeguy said:


> There's an accident waiting to happen if I ever saw one.





Teetorbuilt said:


> I'm an engineer and the project was lightweight, you should consult a local one to appraise your situation.



Good advice from two wise and conservative men who know that the laws of statics and physics are not determined by a majority vote. I also see a few gray hairs showing through here.

Pipe and Teetor,
Nice to hear from you both. It's 4:00 am and I just got in from a cold weather pour (18F). It's time to hit the sack for a couple of hours. I'll talk to you soon.


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## zoso (Oct 7, 2005)

I'm a decent carpenter, but the engineering aspect is a little over my head. I should probably have my engineer buddy consult. But, this is just one corner post that sits on the foundation, and supports a double-decked porch: three (6)posts and a ledger correspondingly support the porches in total. I thought I'd support the two porches by putting the screw jack under the joists using a 4x4 as a tee, screwjack sitting on concrete. Raise the corner of the structure 4"-6" to level. Then I would carefully saw the rotted section off, and replace that missing piece of the bottom of the post with a block of treated 6x6 without taking the post off. Wait a few months and paint.



i______i_______i - top deck
I______I_______I - 1st deck
I______I_______I - Foundation (right corner post rotten at bottom.)


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## RobertCDF (Aug 18, 2005)

you are liftin 6" you need someone to help you out there. That kind of movement is not good you need to spread that out over a period of time. In that case you cannot use a bottle jack it will lose pressure over time and lower.


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## JustaFramer (Jan 21, 2005)

Where's Might Anvil? Lets make it a party.


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## Teetorbilt (Feb 12, 2004)

Mike, I quit counting the gray ones years ago, it's much quicker to count the dark ones. LOL


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## RobertCDF (Aug 18, 2005)

Mike, I guess you did not read past what you wanted to see I listed the reasons the posts moved AND stated I HAVE NEVER HAD ONE MOVE THAT WAS SUPPORTING A LOAD. sometimes we all get a little hasty and dont level the ground enough or make sure the post is plumb. But I can see that you only read what you want to. I have NO problem with capitalism I do believe we should all get paid a fair wage for our knowledge and the sweat of our brow. But I could probably build him a new deck in the $10,000 dollar range and forget the whole thing. Being that he wants to raise it 6" I do agree that he needs to call someone who does do this alot. I may not have given him the same advice if he had included all the info in the first post.


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## Teetorbilt (Feb 12, 2004)

Robert, you have to understand that the 6" settling (in my case) occured over 20+ years and has affected many other parts of the structure. You can't just lift it in a day or two, my case was pretty extreme and had plenty of exclusions in the contract.


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## wasdifferent (Dec 18, 2004)

RobertCDF said:


> ...Being that he wants to raise it 6" I do agree that he needs to call someone who does do this alot. I may not have given him the same advice if he had included all the info in the first post...


By god, you've got it now. I'm proud of you.:thumbsup:




RobertCDF said:


> ...Mike, I guess you did not read past what you wanted to see I listed the reasons the posts moved...


I read it. It's not _really_ wrong, but it is woefully incomplete. You do not yet have a good understanding of the implications of Euler's work.
Best regards,


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## wasdifferent (Dec 18, 2004)

zoso said:


> ...the engineering aspect is a little over my head...


zoso,
The ability to recognize this is paramount to success in the construction business. You are on the right path. Good luck with your project.
Best wishes,


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## zoso (Oct 7, 2005)

And the key to success is to suround yourself with people who do. Quarter backs don't need to hit hard.


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## ProWallGuy (Oct 17, 2003)

zoso said:


> And the key to success is to suround yourself with people who do. Quarter backs don't need to hit hard.


Profound statement of the day. :thumbsup:


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