Should I DIY repair a rotted out back porch support column?

[Megatron]

My wife and I recently purchased a 2 flat multi-family building in a shortsale less than 2 months ago. We are slowly fixing up and making repairs with the help of my Dad and uncles. The previous owner hired a guy to look after it but you know how it goes. We found out that one of the support columns for the enclosed back porch is far more rotten than we thought. It was caused by a broken gutter down sprout that have been leaking water in all last winter. I already had a porch guy come by to take a look and he said he could rebuild the whole deck/porch inside along with stairs and replacing the bottom rotting part of the support column and bring some of the minor things up to code. He said the enclosing walls are good and can be kept. The smaller 2x6s along the wall and next to the rotting column seems to be in okay shape. (I tried to stick a screwdriver into the wood and it seems to be solid). There's probably about 2-3 feet of rotting on the bottom of the column so currently the weight is all on the wall and the 2x6s on the wall. The whole project will cost around $7500. I plan on getting more estimates but I wanted to ask you guys first since this has been my Oracle the last 2 years. My Dad who has a rental building of his own and has some experiences in construction when he was younger thinks that we can DIY this. Basically just jack up porch and cut out that bottom part and replace with a dry / pressure treated column. However, he has not done this kind of thing and it seems like a helleva project for first time home owners. We have the money for a contractor to do this but part of me think it's a good learning experience. Also part of me fears that I might be way over my head. I was also looking at jacks at home depot yesterday and seeing what the cost would be. Any advice would be awesome. thanks MMMs.

[Javelin]

I just completed the exact same project for about $1000. It sounds like you have it right.

I had to pull the old siding in the area. Rip out everything inside down to the studs. Run a 4x6 along all the joists and jacked it up to level with 20 ton jacks. sawzall the old 6x6 post. install a galvanized post base. Jack everything up another 1/4". Install the new post and nail in some steel straps. Reinstall the siding.

[Megatron]

It sounds like you have it right.

haha, right about which part? that I'm way over my head or right that I should hire a contractor? How many jacks did you use for that process?

Looks like you did a great job.

I'm worry that the whole damn thing might collapse any moment.
I mean structurally, the main corner column is basically gone since last winter, it looks like the bunch of the 2x4s have been holding it up. Here's a zoom out picture of the porch. it's 2 stories.

Here are some more photos

[Javelin]

Ok I looked at your pictures more closely. I would pull the siding in that area and replace the rotten portion of the 6x6 from the outside. DONT mess with the 2x's that are basically holding everything up.

The jacks would be used to bring everything back to level. From the picture it looks like that corner is sagging down a little.

I used 5 screw jacks and left one in the wall because I was afraid to remove it. You won't need that many... Maybe 3? Definitely get the tall ones. I made the mistake of using the shorties.

I'll warn you that my project took the entire summer. It's a beast of a job, but tearing out rotten wood is very cathartic. I had 2 layers of tongue and groove planks to rip out of the interior followed by about 30 garbage bags full of crumpled newspapers from 1937. Does using newspaper as insulation make you a mustachian?

Yours shouldn't take that long. $7500 seems a little high depending on where you live, but a contractor might need to hire an engineer, get permits, blah blah. I skipped all that garbage.

[Megatron]

We are in Chicago. that 7500 includes putting in new decks (first and second floor) and all the stairs inside. He said some of the stuff are not up to code. It includes adding 3 more columns in there for support and repairing the new columns. Thanks for the info. I'll go get more estimates and go from there and with the winter coming, I want to get this fix asap. Not sure if it can withstand another Chicago winter.