MCRP 12-10B.1, page 208

(7) Begin improving a hasty position immediately after occupation. (8) Use construction material that is readily available in the built-up area for prepared positions. (9) Remember that positions that provide cover at ground level may not provide cover on higher floors. f. In attacking a built-up area, recoilless weapon and ATGM crews may be hampered in choosing firing positions by the backblast of their weapons. They may not have enough time to knock out walls in buildings and clear backblast areas. They should select positions that allow the backblast to escape, such as corner windows where the round fired goes out one window and the backblast escapes from another. The corner of a building can be improved with sandbags to create a firing position (Figure A-59). Figure A-59. Corner Firing Position g. The rifle squad is often reinforced with attached antitank weapons during an attack on and in defense of a built-up area. Therefore, the rifle squad leader should be able to choose good firing positions for the antitank weapons under his/her control. h. Various principles for employing antitank weapons have universal applications, such as making maximum use of available cover, trying to achieve mutual support, and allowing for the backblast when positioning recoilless weapons, TOWs, Dragons, and AT4s. Military Operations on Urbanized Terrain A - 47