EverbuildOpti-Mix 3 in 1 Render Additive – Waterproofing Agent – Super Concentrated – Easy To Use – Yellow – 1 Litre

It works

Used it many times before and will carry on using it (used for rendering)

So I needed to repair some damage to the render on my gable wall on a very old stone property and this product looked to be ideal to help with the job.The instructions are simple enough... just add the correct dose to 10 litres of water using the measuring cup on top of the bottle, which is effectively one standard bucket full.I used the maximum suggested 40ml for 10 litres and would probably use even less next time. I used the Opti-mix in a 2:2:1 mix (Sharp sand / Fine sand / Cement) for a fairly deep scratch-coat, followed by a 4:1 mix (Fine sand / Cement) a couple of days later for the finishing-coat.I have to say that the Opti-mix makes a real difference to the mix. It makes it creamy and buttery and gives loads of working time to do the job without it drying out or shrinking. It makes the render easy to work with and it adheres well to the wall allowing plenty of time to get a good finish. I also found that it performed equally well with the different sand / cement ratios that I used.Finally, I had some mix left over during both stages of the job and didn’t want to waste it, so I used it to carry out some pointIng on a stone wall and again found it to be really easy to work with.The only slight issue I had was with the product shelf-life, which is two years from the date of manufacturing. In my case, the bottle I received had been made in Feb 2019, which effectively means that I’ve only got 6 months to use it, so you might want to watch out for that.As for the product itself... highly recommended.

Used this for pointing on paving slabs. Usually I'd just a very cheap washing up liquid for a plastisiser, but being liable to be under standing water, I chose to use this.As a plastisiser it's ok, being workable for quite a while without crumbling. I was hoping the waterproofing would be quite obvious, but it doesn't appear to be much more repellent than mortar sans this.It may be less porous and thus less prone to frost, but water seeps through from what I can see.The biggest problem is that it doesn't look like there was a full litre. A colour additive of 1 litre weighed 1.6kg in a bottle of similar design, whereas this was just over 1kg. Picture shows 3/4 full bottle.

Good quality

This is an inferior product and not a salt inhibitor as stated I had to return to 3 jobs to rectify where this stuff failed,even contacted ever build about this and they didn't want to know.Inferior product.

I used this on the back of a large retaining wall and to line inside of planters to protect the face brickwork from the constant damp conditions, it make the render nice and workable and seems to be completely waterproof as there absolutely no wet spots on the face work after wet conditions

As an experiment I made a very small indoor water feature out of cement and then put two layers of this over and around all the water bearing channels and container areas of it. The result - although it remains bare and undecorated (making it pretty is on my todo list) is very good. No leakage or seepage.Now going to use the remainder of this on an old concrete runnel which takes water away from our garage gutters to the drain. It has cracks which I am sure leak into the ground underneath so this should sort things out!