I'm trying to wire my basement ,but I have a few problems here we go
1)my main breaker box has no more space for breaker,even the ones that I have now are the split small ones
2)the breaker panel is outside the house
The questions are
1)since there is no more space in panel can I run a line from the main 100 amp breaker or I need to run it from a different breaker?
2)do I need to run the wire in a water tight conduit outside and inside the house?
3)im only going to be using 35 amps in the basement ,so if I borrow the amps from the main breaker is this going to cause the breaker to pop?
Please give some ideas
Should I hire an electrician to run the power to the subpanel for me ,I can get it done from there
Thanks a lot

Yes to calling an electrician. However, from your description of your SEP (main panel) you are already maxed out.

Maybe it is time for you to consider going to 200 Amp service, The SEP panel will just about double the amount of breakers you can safely install.

However, I will defer to several of the licensed electricians on this board. Hopefully TK Russell, the moderator can make better suggestions then I have.