Originally posted by westcoaststyle
FYI, it's called 'decking'. 
You should talk to a machine shop that deals with a lot of Hondas. They should know how much would be safe.
Personally, that seems like a jerry-rig way to raise compression. Once you do that, you can never go back without replacing the head. Why not just get new pistons? That way you still have the ability to change things in the future.
Also realize that when you raise compression, you're putting more stress on the internals and the head gasket. You should upgrade these parts if you plan to raise it as much as you're talking.
JMO. 
im a senior in high school and i take a machine tool class for 3 hours a day...my dad is a machinist so i have grown up with it and i know a little about it...i also rebuild cylinder heads in my spare time but there is not a lot of imports around so i mainly work on V-8's..i have decked several blocks and heads but im still not really familiar with 4 cylinders...thats why i wasn't sure about the clearance...i also recently bought another accord with an engine with considerably less miles so i always have a back up motor....i'm going to order a thicker gasket so i thought since it won't cost me anything to "deck" the head myself it will make up for the thicker gasket.