Another possibility is to put the lifting gas into gas bags and put these in turn into an air-filled envelope. This is only useful in smaller airships. Of course the gas bags must be partially flat, and the envelope must be pressurised, usually by blowers.
And all this airship stuff always involves some TLC, seven days a week, 365 days a year. One of my former colleagues used to explain it like this: "Airships are like horses. You can put an airplane or a car in the back of a shed and ignore it for a couple weeks or even months, and it will in be almost in the same shape as when you put it in. But an airship or a horse... not so!"
I'm having some Beck's right now.