Not for points English Art/Literary Poetry & Literature understanding an expression

I am translating an English novel into Hungarian. The writer uses plenty of artistic, creative images in the text. I encountered "floor of the sky" two times:

"The sun below the horizon shot pink arms along the clear floor of the sky. The waiting air was thin and still. Cattle in the next field, statues of petrified flesh, faced the eastern rim of the morning world, and waited. The leaves in the distant trees were motionless."

and later:

"A drop of rain, large and heavy as a penny, splashed my handle bars. Then another, and another. I gaped upward, open-mouthed. A black carpet of cloud unrolled across the floor of the sky, reached for the sun, and the sun lost its heat and was swept under the carpet like golden dust."

Does this expression refer to the imaginary surface of the sky? Is this expression used at all in spoken language?
Thank you for your help