Joined: Feb. 2018
||Posted: 26 May 2018,17:18
Never had to go back to a job once in over 10 years as a sole trader, except to adjust a patio where a conservatory had since been built or to to do additional works for a happy customer. That was until my local builders yard switched suppliers and sent out EcoCem instead of their usual brand of ordinary portland cement.
Pretty much every mix I've made for a good few years now (bar mortar for facing bricks) I've added at least a dash of Ever Build 503 Premium SBR to the water, buy it in 25l containers and always have it to hand. Magic stuff, I used it originally for making slurry mixes for welding on step treads and copings, but found it just too tempting not to share the love in haunching mixes, beds and jointing mixes.
Thing is, Oct/Nov last year, I used EcoCem + this premium SBR on 2 jobs within weeks of each other, and on both, the concrete and mortar has gone to powdery shit. In one instance, a 5:1 mortar mix went a very odd orange/yellow colour, powdery and crumbled to dust. Never seen anything like it - it's like someone added an icky buff dye and the temperature dropped to minus 30 like 5 minutes after my trowel left it. In another, three sections of 2:3:1 concrete (20mm limestone, zone 2, ecocem), of these 1 is perfectly fine and as rock-hard as you'd expect, the other 2 (both installed same day) are a little discoloured, crumbly and take little effort to turn back to sand and stone under the sole of my boot. Given the timing of the job after others, it seems likely the good section was where I used up the last of the proper cement I had over from the previous job.
So yeah, mightily pissed off.
Not sure what this stuff is made from, but quickly skimmed a page saying it was some sort of reconstituted waste product that gets bagged up and passed off as cement. WTF?! It might well take 25% less carbon to produce, but if it's not a direct swap-out for OPC, it shouldn't be offered as such. And in fairness, nowhere on the packaging did it claim to from what I remember, but the builders yard shipped it out as such, so that point is moot.
So just saying beware if this stuff lands on your site. Whatever the eff EcoCem is, it ain't OPC (more like PoC!) and I'll not be going anywhere near it in future. If it ballses up so spectacularly with SBR added, who knows what myriad other additives, stabilisers, plasticisers etc. will do when brought into contact with this stuff. My advice is, if you're not using it straight, don't assume it'll act as if it were OPC. Actually, it's just steer well clear full stop and use the same, trusted and tested OPC you always have that you know is good.
Ironically, it might well be that using it straight would have produced the expected results, and if I hadn't poured expensive SBR into the mix it'd have been fine, but whatevs, that's no effing consolation when you've grafted and have to go back do repeat work for no fault of your own.
End of rant.
Kevin W. Dempsey kwdConstruction http://www.kwdc.co.uk