To be fair, the internal frame of the upper structure is steel.  
<a href="http:&#x2F;&#x2F;i.imgur.com&#x2F;JLIlRf3.jpg" rel="nofollow">http:&#x2F;&#x2F;i.imgur.com&#x2F;JLIlRf3.jpg</a>
<a href="http:&#x2F;&#x2F;media.details.com&#x2F;photos&#x2F;5637e54e62b3b75f2bb3e531&#x2F;master&#x2F;w_806&#x2F;2-la-mansion.jpg" rel="nofollow">http:&#x2F;&#x2F;media.details.com&#x2F;photos&#x2F;5637e54e62b3b75f2bb3e531&#x2F;mas...</a><p>Isn&#x27;t it a little strange to be comparing plywood with 3&quot; teak? Can you even get sheets of teak that aren&#x27;t a veneer? Wouldn&#x27;t LVLs or glulams be a more apt comparison?