Thanks for using Avvo. I am an Avvo Staff Moderator. To read more about our moderation team, follow the link below. Our current question volume may increase the response times of our loyal Avvo lawyer-answerers. My goal is to give you some preliminary information and guidance regarding your legal situation while you wait for an attorney in your area to respond.
I borrowed this answer from another Avvo contributor John Donald Sullivan (see link below).
"Washington does not have a commercial landlord tenant act. Landlord and tenant rights and responsibilities are generally found by reading the lease or, if the lease is silent, incomplete or unclear, by looking at the common law."
If you would like a definitive answer to your particular question, I have also provided a link to a local attorney referral service. They can put you in touch with a commercial lease specialist who will usually charge a nominal fee for a 30 minute consultation.