A special hand tool for laying concrete blocks. The device includes a mini-hopper sized to hold the correct amount of mortar, a sluiceway, dimensioned to fill the normal joint space between blocks, an optional divider to accommodate both 4 inch and 8 inch nominal blocks, and a vibrator. The device has a handle that can also contain batteries for the vibrator. A mason can scoop up mortar while the tool is vibrating. When full, the vibrator can be stopped and the tool positioned to face the end of a block already set in a wall while the next block to be laid can be put in place on its mortar bed and pushed to the other face of the tool. The vibrator can then be re-started, and the tool vertically withdrawn leaving the mortar that was in the tool between the two block ends. The same tool can also be used to butter horizontal joints by running the vibrator only sufficiently to apply the correct amount of mortar. Alternatively, a second similar tool sized equal to the length of a block, containing exactly the right amount of mortar for a horizontal joint, can be used.