poecilotheria molting

[Spiderman24]

What are ways you can tell they are ready to "POP"? The only thing I've ever heard to go by is dull color and reason I'm asking is because I've got an eight inch p.ornata that has abounded her hide to go "out back" and build a giant dome of web and substrate. Could this be stress related? My house has been quite noisy this past week and lots of people coming in and checking the ladies and gentlemen (I had to laugh just typing that) out? Or is this molting time? Most of my pokies I just come across half way through a molt and that's out in the open or on there already made webs. I've only ever witnessed from the start.my new p.Miranda and she basically just climbed to the inside top of her hide and dropped then about two hours later I had a molted t. Any input would be big help
Thanks guys