I know variations of this question have been discussed here and over at TBN, but never really got consensus on my particular situation so I'll throw it out here.

I have an existing 32x26 shop building with a dirt/gravel floor. The building has been up for about 40 years and has been used to store tractors etc for most of that time (point being the floor is pretty well compacted I would think).

The foundation is cinder-block, and I assume, but am not positive, that it extends all the way down to the frost line and most likely has footers in place.

I want to pour a cement floor into this building by fall (I am in New England), and here is what I am thinking I should do:


Use 2x6 (or 2x8) boards laid on edge(and secured) in front of the doorways to hold in the pour. (i.e. a form). I was hoping I could use the existing cinder-block walls as the rest of the "form"...any reasons I can't pour right up against the wall? or do I need to put in a form and remove it later so that I have an expansion joint between the existing wall and floor around the whole outside perimeter?

Also, I'd like to pour directly onto the existing floor without excavating down...I was thinking 4-6 inches thick with proper amounts of wiremesh in place...raising the floor this way would solve two problems: first make it less work [img]/forums/images/icons/smile.gif[/img] and two, it would leave the finish grade high enough to prevent water from running in the front; keeping all my tools nice and dry.

Is there any need to "subdivide" the floor? i.e. leave expansion joints thru the middle? I am hoping not, so that I end up with a smooth 32x26 slab w/no obstructions...

Lastly, I have done small amounts of cemet work myself, but his would be the largest pour by far...how much skill is required to end up with a nice smooth finished surface?...I'll only get one try to get it right and don't want a real irregular surface when I am done..

ANy other suggestions?

Thanks all in advance for the help.