The Brew Cabin

Should I compact the blocks before scattering with kiln dried sand? Or should I brush the sand in first?

I tried a trial section (to see how much they would compact down with the vibrating plate) and found many of the blocks just wobbled

Somewhat related to this, at the edge of the driveway up against the house I have blocks bedded in mortar. I put a slope to the mortar (about 45deg). The thickness of the bedding sand for the adjacent blocks is therefore variable and is zero actually at the edge. Is this correct and will it make the edge blocks harder to compact?

We have always found that we get best results if the jointing sand is brushed in first. I know some manufacturers state in their literature that blocks should be compacted first then sanded, but what the hell do they know? ;)

If the blocks are compacted 'dry', some joints tighten up and some widen, whereas, if sand is scattered over the surface, it seems to even out joint width, minimise skewing of individual blocks, keep cut blocks in place and, most importantly, ensures the sand is properly rattled into the joints so that those nasty empty joints that appear after a couple of weeks or so after completion are fewer, meaning less maintenance at the 6-week check-up.

I'm not sure why you;ve laid the edge blocks like that - I'd have laid them on a full concrete bed and hammered them down to level there and then, so that the body blocks acn be laid on a full sand bed. As I've never experienced blocks laid in that manner, I can't be sure how they'll respond to final compaction, but my guess is that they'll 'dip' at the sand end while staying more-or-less put at the mortar end.

I'd be interested to hear what happens!

Thanks,

I was showing my ignorance and treated the blocks bedded in mortar at the side as needing haunching. I now realsie that they are there mainly to provide a level against which to screed.

Thanks

jonathan