We are removing up to 0.75 in. (19 mm) of the existing scaled concrete on a fire-damaged concrete wall. The architect has asked if shotcrete is applicable for a vertical 0.75 in. (19 mm) application. Also, the walls are circular and the working distance from the wall is no more than 36 in. (0.9 m). Is this enough room to apply shotcrete?

Yes, shotcrete can be applied in a 36 in. (0.9 m) area. Keep in mind, however, that it’s difficult to get as nice a gunning pattern as you would like when you are that close to the receiving surface. When you cannot back off from the wall, there is a tendency for a more irregular gunning surface, which would require more cutting and screeding to get an aesthetically pleasing result.