How can I replace laminate with polished concrete flooring?

Question

I'd like to investigate whether I can replace my first-level flooring - currently faux-wood laminate - with polished concrete. What do I need to know?

• Is it even practical to put down polished concrete as 'old work'? How much margin around the edging is needed? i.e. Will I need to pull off the baseboards (or can I get away with just pulling up the trim over the hardwood edge), will kitchen cabinets need to be removed/replaced, etc.?
• What are all the steps involved? Which, if any, are better done by a professional?
• How to deal with the subfloor, and if the current subfloor is not suited, can it be modified to support concrete? I'm not yet 100% sure if there's a slab underneath.
• Any other big questions I'm not asking?

Answer 1

The main problem you will have is thickness, thin concrete tends to crack. Your laminate flooring is all of 1/2 inches thick most likely, so the maximum your concrete floor could be is that much, and that's not enough. Other problems are:

• unless you are pouring on slab the flexing of your floor will cause the concrete to crack
• unless you are pouring on slab the concrete will drop between the floorboards
• unless you are pouring on slab the floor will probably not be designed to take the weight and could lead to structural problems
• Creating polished concrete requires special materials and repeated sanding with ever finer diamond wheels, equipment which would be very expensive even to rent, presuming you can rent it

I'm not saying it's impossible, if you're on slab you might be ok, but if it were me I'd be considering a cool looking tile rather than polished concrete.

Answer 2

Concrete floors are typically installed as part of the overall construction process. The slab is taken care of enough to be the actual floor, then the house built on top of it.

If your house is on top of a slab, you'd basically see if you can rip out the floor completely to expose the slab, and perhaps float a new layer of concrete on top to bring it up to the level of your old floor. You'd have to empty your room completely to do this, of course, and possibly have to redo the walls as well.

You may want to consider concrete tiles instead. It'd be a more practical retrofit.