i am going to lay a new block paving patio apprx 3 meters by 10 meters. i am going to concrete the edges in first, but my problem is how much bigger do i leave the internal size between edge to edge. ie 10 blocks by 10 blocks = 1000mm x 1000mm. i do not want to have any cuts. the blocks that i am thinking of using are marshalls driveline 50.
i was going to leave maybe 5mm bigger on the 3 meter size and 15mm bigger on the 10 meter size.
i think the blocks are 200mm x100m with spacer lug included.
Thanks Geoff
Tolerance - Block paving
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Tony McC
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Use the 'Floating Edge" method described on the Block Paving Edges page of the main website.
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Tony McC
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It's not possible to give a definitive answer. I'd normally say 24 hours, giving the haunching a chance to harden-off before final compaction, but I oversaw a job in Co. Limerick a couple of weeks back where the floating edge course was laid and haunched in the morning session (9-12 noon), the rest of the path laid during the afternoon (1-4pm) and the lot was compacted around 4.30pm, with no obvious problems. The lads had laid the edge course a little bit on the 'tight' side, so that the edge course blocks were forced back into the haunching by 5-10mm or so for large parts of the path when the body blocks were placed. There was one significant stretch of 10-12m where the edge course was 'wide' and had to be moved back in, if you know what I mean, and so we topped-up the haunching, filling the gap between the morning's haunch and the back of the blocks with a bit of stiff, fresh sand/cement @ 4:1, and that seemed to hold.
I know the path was checked for practical completion yesterday (Monday) and passed as 'acceptable' by the resident engineer, so wackering so soon after haunching doesn't seem to have done any real harm. I should point out, though, that the path was only 1800mm wide, laid using 80mm deep blocks in a longitudinal running bond with a tranverse, 200mm wide soldier edge course. There was a generous 40-50mm of crossfall away from the rear edge course, and said edge course was laid on 100mm of semi-dry 4:1 grit sand/cement, haunched with a ghood 100-150mm of moist mix sand/cement/6mm chips roughly C20 strength (1:2:4).
If you think your project could hold up, give it a go, but if you notice any 'spread' as the plate passes close to the edge course, it's probably best to leave it overnight. I'd be interested to hear how you get on.
I know the path was checked for practical completion yesterday (Monday) and passed as 'acceptable' by the resident engineer, so wackering so soon after haunching doesn't seem to have done any real harm. I should point out, though, that the path was only 1800mm wide, laid using 80mm deep blocks in a longitudinal running bond with a tranverse, 200mm wide soldier edge course. There was a generous 40-50mm of crossfall away from the rear edge course, and said edge course was laid on 100mm of semi-dry 4:1 grit sand/cement, haunched with a ghood 100-150mm of moist mix sand/cement/6mm chips roughly C20 strength (1:2:4).
If you think your project could hold up, give it a go, but if you notice any 'spread' as the plate passes close to the edge course, it's probably best to leave it overnight. I'd be interested to hear how you get on.
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