Thread: brick sill

You probably have too much water in your mortar mix. You need only enough to promote the chemical reaction - much stiffer than peanut butter.

In very heavy stone construction, masons often use lead setting buttons to hold the joint size consistent. You might try collecting some pebbles, or some bullets, of two uniform sizes. The smaller ones near the bottom edge, and the larger ones inboard, to establish slope.

Cheers,
Joe

Probably too wet a mud, but you may also be overworking the bricks.

Once a brick's in place, don't keep fiddling with it to get it right. Get it "near enough" and move on. Once you've finished the sill you can come back and use your hammer and a short spirit level to gently line them all up properly with a tap or two. The mud should've gone off enough that it won't affect neighbouring bricks unless you - again - try overworking them.

If tapping one shifts another, go have a quick coffee or wash your tools... and come back when the mud's a bit stiffer. But don't wait too long!

And... yeah. Many an Aussie window sill has small lumps of gravel propping up the back edge of the bricks.