I’m joining treated pine sleepers to hold back woodchips, using galvanised T joiner steel sleeper pegs (MaximMetals). Should the side of the joiner with bolt heads used to attach to the sleepers be facing the ‘visible’ (good or out) side, or should that side be facing the woodchips? Or, doesn’t it matter?! In the picture here, I’ve tentatively placed the joiner facing the woodchips
Welcome to the Bunnings Workshop community. It's fabulous to have you join us, and thank you for sharing your question about the proper orientation of the T sleeper peg.
The forces generated on the sleepers usually comes from the soil inside the garden. This force multiplied over time is what causes the sleepers to move and tip over. To keep the sleepers in line a Sleeper Peg is usually attached to prevent the sleeper from moving. In this instance, the "T" is suppose to be on the other side. The reason for this is the wings of the "T" actually hold the sleepers back and keep them straight. If you were to install it in its current configuration the sleepers will continue to lean out. If you have any other questions, please don't hesitate to post them.
If you need further assistance, please let us know.