Sheathing

To put (something such as a knife or sword) into a sheath.

To encase (something) with a protective covering.

Of an animal: to draw back or retract (a body part) into the body, such as claws into a paw.

To thrust (a sharp object like a sword, a claw, or a tusk) into something.

Something that wraps around or surrounds something, as a sheath encases its blade.

"When the sheathing was on it suddenly looked like a real house: you could see where the outer walls would be even if they still needed the siding and trim added."