The wheel housing opening shall allow for easy tire removal and service. The wheel housing shall be attached to the floor sheets in such a manner as to prevent dust, water, or fumes from entering the body. The inside height of the wheel housing above the floor line may not exceed 10 inches. The wheel housing shall provide clearance for the installation and use of tire chains on single and dual, if so equipped, power driving wheels. No part of a raised wheel housing may extend into the emergency door opening.