Reno - I was thinking no romex because of the moisture factor. Also, not sure what you mean by "build a box". Do you mean create a structure within the structure? Don't think that would work: the triangles of this dome are translucent pieces made specifically for that filtered sunlight effect; don't want to block them in any way. The structure connecting each triangle to the next is 2x4 wood, with the 2" face being the surface I could strap to. Not too concerned about that. Just wondering if sealtight seems like a reasonable way to go and, if so, how to go about strapping with the 1/4" spacing required by 300.6(c). Thanks.