Floor Leveling Help

[novawestguy]

I need some advice on leveling a floor in the kitchen of a townhouse to prep for laying laminate. The area that needs leveling is where a cantilevered box bay window is attached to the back of the kitchen. It was obviously not installed level to begin with, and the floor angles down about 3/4". The area that needs to be leveled to the main floor is approx 4.5' x 3'.
Do these "self-leveling" compounds really "self level" or do I need to level the area off with like a 2x4 since it doesn't seem like I would have enough time to trowel that much area out before it starts to set.
Can anyone give me an idea of the best type of self leveler to use ?.
I am prepping over the top of existing vinyl flooring, which I was told I did not need to remove.
Any assistance would be greatly appreciated...ask for any more information if needed. Thanx in advance.

[Jimmer]

Hi there, I've used a couple different brands of self leveling compounds and found them to work very well. You want to follow the mix instructions closely and use clean, cool water. I normally use a trowel to assist in the spreading. An option for you is to lay down a screed rail (just a strip of wood) against the far wall and use a straight board to help spread and level. You would have one end of the board sliding across the screed rail and the other end on the floor that is the right height. Make sense? I would personally remove the old vinyl to allow for a better bond.

[HayZee518]

I have used only one product called LEVALASTIC - I don't know if they even make the stuff anymore. It is a portland cement mix with a latex binder. With the consistency of fine sand you mix the two together and spread it around just like a mortar mix. Once it cures, because of the latex binder it flexes without cracking.