Replacing Foundation on Shed/Cottage

[2MuchDIY]

We recently bought a brick home built in 1962. It came with the nicest "shed" I have ever seen in the backyard. It's approximately 25x25 and has stairs inside up to the second floor loft. The shed currently has no utilities or sheetrock, but has 4 windows on each floor and some insulation. It's approximately 30 years old and was built by the only other owner of the house who was a carpenter.

Our plan is to turn this shed into a 1 bedroom cottage to rent out for extra income. The problem is that the foundation is a series of 6x6 pressure treated posts presumably on concrete footings and most of them are rotting. I believe the cause of the rot is a combination of the lack of gutters so that the roof water falls directly down to right next to the posts as well as the slight grade of the small yard towards the shed. I realize that these issues will need to be addressed.

The current "crawl space" is VERY tight. On the lowest side it is only an inch or two from the ground and the highest side is a little over a foot. Since I need to run plumbing, I would like to lift the shed when replacing the foundation and have a proper sized crawl space.

Should I replace the posts with new 6x6's and then put up skirting of some type for aesthetics? Or should I use a block foundation? What are the pros and cons of each?

Is lifting this building something I can do with some friends and jacks, or do I need to hire a house moving company?

What other aspects should I be considering? Any guess at the ball-park cost of replacing the foundation?

Thanks in advance for your knowledge and help!

 

[bud16415]

The building you have around here is commonly called pole barn construction and they are often called 40 year buildings referring to post life. The strength of the building comes from the posts and I would be afraid to cut them all off and lift the building to put a new foundation under it. I’m sure it could be done but it might cost as much as the building is worth to do. Around here most people extend the life by adding in new posts one at a time or splicing them just adding the lower part. Doing that you should be good for another 40 years.

Most don’t have a crawl space though its common to build such a building and then pour the floor inside it. Some people set the poles and set the lower skirt around and then pour the floor. Yours sounds like it has a wood floor. If you could post a few photos I’m sure you will get quite a few replies on what is the best way to go.

How have you determined all the poles are bad?

on edit
On another note you should check if you haven’t yet as to local codes and if what you have planned for the building is allowed in your community. We allow this type of building as a garage / shed or an agricultural use building and some townships will allow you to live in one many wont. Don’t spend a lot of money before you know for sure.

 

[oldognewtrick]

First off to House Repair Talk!

What part of the country are you in? What type of soil conditions do you have? Are you planning on permitting this project? Will codes allow for rental property? What condition is the floor joists and sill plate in? How are you planning to make the services to the unit if you are in a freeze zone?

Providing pictures is always helpful when asking for advise.

 

[JoeD]

25x25 would not classify as shed here. That is garage or second building. The work you are describing would require a building permit.
I would go with concrete posts set into the ground. The depth depends on your location.