The biggest move for the Houston Texans following their last preseason game regarding their roster was to sign tackle Ryan Harris to replace the recently injured Rashad Butler. Butler was forced onto injured reserve after being knocked out of the Texans' final preseason match against the Vikings.
There might be another tackle added to the roster in some capacity, according to Battle Red Blog. Currently, their practice squad roster has several different positions filled, but no offensive tackles. They have one spot remaining, which will more than likely go to a tackle:
I would guess they will go offensive line shopping, as the Texans usually carry an offensive lineman on the practice squad. I would be mildly surprised if they did not add a young, developmental tackle as the final member of the practice squad.