As for engraving constructed floors and walls, it's not possible. At all. If you want engraved above-ground constructions, I recommend looking into cast obsidian.
Aaaaye, lad, take a seat, and I'll tell you a story of how it used to be in the olden days.
Back in the Age of Myths, back when I was just a wee li'l lad not much older than yourself, you could engrave on constructed walls. 'Tis the truth! Even to the very tippy top of a Diorite Tower that rose until ye could touch the sky itself, it would be fuller than a female cat is of kittens.
Aye, everyone loved seeing the engravings, but there was discontent. The Engravers would march down the halls, heads held high, and all the womendwarves would twitter amongst themselves about his latest engraving of himself engraving an engraving, and they'd waggle their beards at him most suggestively.
And this would infuriate the Masons to no end, for no one ever much bothered to notice *their* work. No, it was all, "Another group of migrants, I need 100 doors by tomorrow," or, "No, no, no! These statues are only exceptional quality! I demand masterpieces! Dump them in the magma and do it RIGHT!"
And so the Masons saw the Engravers come by the walls they had lovingly constructed, and make a few chisels, and then go to party in the +Statue Garden+ while the masons had to work the weekend *again*, and they grew Jealous.
So it came to pass that, one day, the Engravers found that a wall blocked their access to the fort -- a wall that wasn't there yesterday was there now. It wasn't until some days later that their disappearance was noted, and the Masons had to be called in to deconstruct the mysteriously created wall.
From then on, it was war.
The Engravers covered the dining room with vermin that the Masons detested. The Masons would come by and deconstruct the Engraver's masterpieces. The Engravers would make depictions of the Masons making plaintive gestures to one-armed goblins constantly passing out from pain.
Finally, one day, while one of the Engravers was flirting with a particularly well endowed (in the beard department) womansdwarf, that there was a cave in! A slab of rock, exactly square, 5' x 5', fell from the ceiling and smote the Engraver flat.
There was no Justice to be dispensed to the Masons, for they had not struck the Engraver...but the Engraver was well-liked and had many acquiantances, and soon many of the Mason's masterpieces had been found smashed, and the Masons took their tools, and...
And, well, once the reclamation party had arrived, and pieced together what had happened, a truce was arranged between the Masons and the Stoneworkers, so that neither would be stepping on the other's toes. And that's the way it's been ever since.