Roger Cicala of LensRentals has posted a partial teardown of the Tamron 15-30mm f/2.8 Di VC USD lens.
His takeaway? Tamron's latest wide-angle zoom is well built but isn't nearly as modular as most of Canon's newest lenses; fixing one at home is not necessarily recommended because of the complex nature of the lens's construction.
Check out the LensRentals Blog for the well-illustrated (and equally entertaining) partial teardown.
B&H carries the Tamron SP 15-30mm f/2.8 Di VC USD Lens (review).