Overhead Poured Floor

landmark

I have a customer with an attatched garage that has the floor puored with storage space below, the floor has cracked in several places and is drooping between 4 and 5 inches with pieces falling off the bottom. I already know the floor needs to be removed, it is beyond repair because some of the rebar has corroded from salt leaking from the cars parked on it during the wintertime.
This would be the first floor of this type for me to tackle, any ideas on where to start? the garage is 24x30.
How would the new floor be poured and does anyone have any ideas on costs to remove and replace this type of floor?
One problem i can see which may be difficult to get around is getting a new floor poured on top of the walls without removing the existing garage structure first. questions or comments to get me thinking of some options?

K2

We did one of those but we did normal framing with an engineered floor system then poured the concrete on the subfloor and the floor framing stayed in place. If your walls are built on top of the poured concrete I think you will have quite a chore. I don't think I'd consider it unless there was a structural engineer involved and a hefty buget.

PipeGuy

BINGO!

6stringmason

A big budget will be needed for sure. Only thing I could think of is spancrete. But you cant place it with garage structure in place already. Good luck!

stacker

i think if it was me i would turn tail and run to my truck as fast as my butt would allow.
but on the other hand you didnt say how big of storage area below there is.is it full size like a basement?if not then maybe a person could cut the slab a couple feet away from the garage walls,leaving that concrete so the garage walls have a place to stay.then a new slab could be poured.properly pinned into the old concrete,the new slab shouldnt go anywhere.if the storage area isnt very big,i would try to talk the customer into filling the area in and pouring over it.completly doing away with it.if the need the space,they could build a small building behind their house with money saved.
good luck.

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skylands

Once you put the project in perspective, it's not that bad. It all depends on the homeowners attachment to the building. Our projects are generally for larger older homes with historic or emotional attachments.

We've raised buildings to replace floor systems both wood and concrete. This type of project requires lifting the building by the ceiling joists. You need to build a cradle with beams that extend past the outer walls by about 4 feet.

Most important feature is "take your time, involve as few people as possible and constantly check the condition of the cradle." Biggest mistake is to raise the building more then an inch or so past your work area.

Do you need an engineer? IMHO yes. Building the cradle for the first time is not something I recommend without professional guidence.
Is it expensive? You have the engineering costs, lumber (lots of it), jack rental, a crew of at least 3 to build the cradle, and 2 days labor to prep. Then after the new floor is installed, you need to reverse the process plus repair the property.

With all the respect in the world, please consider your crews full potential before you tackle this for the first time. However. Since it's just a garage, it may be a great learning tool for a nitch for you. I actually prefer this to new construction.

landmark

Well after a lot of investigation and working with a engineer I have come up with a plan to fix this. The slab is 24x32 and under it is completely open storage. Losing all the area underneath is really not an option due to the back of the house facing a lake and other property lines nearby which will not allow construction of any new structures on the property. Half of the area will be filled and compacted to pour on top of, the other half will have a wood floor constructed with a room above saving half the space underneath and gaining additional living space. The garage will be bumped out 12' to the front for the needed length.
One thing I have noticed on this site when there is a difficult problem presented are the amount of contractors who leave posts saying in one way or another 'turn tail and dont look back'. Are there really this many people who turn away work when it might be difficult? I could not imagine doing this to any of my customers, I particularly enjoy when a project involves a little more thought than the norm and how does anyone learn if they dont try to tackle the unfamiliar things too(with some help from knowledgeable engineers or other professionals). I dont mean this toward any particular people, it was just an observation that i had about many of the posts.