Hello,
I have a bit of a conundrum. Some mortar has fallen from brickwork behind a wood burner so needs replacing as it puffs out smoke when the burner is lit. The problem is that the hole is in fairly crumbly brickwork, behind a deep lintel (so access is extremely limited and difficult to illuminate) and - worst of all - can only be filled from underneath. I tried expanding foam but you need to hold the can upside down so I ended up trying to apply by hand - the result was no success and sticky hands for a week! Next, tried a standard off-the-shelf mortar mix; mixed different amounts of water in small batches and, of course, wet the brickwork first but there was absolutely no adhesion so mix fell out, regardless of the mix consistency. Could someone please offer any advice as to possible products that can defy gravity? While not directly in contact with the heat from the fire I suspect it would need to withstand a certain amount of heat. The gap, by the way, is gash shaped, probably max depth 4", width 2". Thanks in anticipation...