More questions regarding laminate flooring

Firstly, thank you all for answering my last post regarding the brands available in laminate flooring and for your recomendations. I have come to my next headache with regards to laying the stuff down. I have to work around a fireplace and there is very little space beneath the marble bit that juts out form the fire place (you can tell that I'm new to this can't you ;)) is an irregular shape. Do I need to have an expension space between the flooring and this bit? If I do, how do I go about doing it? I'm even wondering if the underlay will go under that bit protruding out of the fire place. BTW it's fixed to the floor with concrete I think. No easy way to lift it off.
Thanks in advance.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.