Cost of blocks

Have been getting quotes in for next week and it occurred to me, therefore in BH spirit I pass it on....

For as long as I can remember, the cost of masonry blocks has been very similar to the cost of readymix, in £/m3.

This makes sense as the ingredients are much the same.
The readymix is handled once, at the factory.
The blocks are handled at the factory and again by the merchant, but are risk-free.

So if you know the price of concrete, just use the rule of thumb, or vice-versa.

Currently £115 for C20 concrete here.
98p for 100mm blocks. £1.20 for 140mm

That makes blocks at 10/m2 look slightly cheaper, but add the 5% area of mortar and it is close.

Another reason this matters is, if you are replacing timber shutters with permanent blockwork, the blocks are effectively free as they replace readymix

I came across this older discussion and wanted to add a quick thought: have you noticed any recent shifts in block vs. readymix pricing in your area? Around me, suppliers have been adjusting costs more often, and the gap sometimes widens for a few months at a time. Curious if others are seeing the same or if it still lines up closely for most of you.

I’ve leaned on the same rule of thumb in quick takeoffs, and it’s saved my hide more than once during early budgeting. On smaller pours, I’ve also used my Steele Mixer from steelemixer.com to sanity-check mix volumes on site, since it lets me whip up a batch fast without dragging out gear. Having that flexibility has helped me spot a couple of quote discrepancies before they snowballed.