In this heist (shipped with the Wolfpack DLC), you can use planks to barricade the windows and the vents.

Since the cops (especially the snipers, pretty dangereous in this heist) can blow the barricades on windows in only a few shots, leaving you exposed, does anyone know if there's something useful to make of these planks?
Also, how long will the barricaded vents hold ? Is it more interesting to condamn all the vents rather than the "key" windows (for instance, those in the server room, or the ones covering your way out on the roof, at the end of the heist) ?