For Class 1 uprisings, many types of retail stores will provide adequate shelter. those with roll-down gates, solid or otherwise, can stop up to ten zombies for several days. If the siege lasts any longer or if more zombies arrive, the situation may change dramatically. Enough rotting fists, enough heaving forms smashing against the gate will eventually break it down. Always have an alternate escape route planned, so that if the barricade is breached, you can quickly move on. If you can't formulate a solid Plan B, do not consider this place a refuge. Stores without gates should not be considered. Their display windows will do nothing more than advertise you to the zombies.