Hi all, I'm after some advice. I am an experienced DIY'er and have a keen eye for a good finish but I'm clearly not that experienced as I seem to have royally missed a trick with this. I have recently installed 50m2 Karndean (2 months ago) in one area of my house that was solid concrete about 25 years old. I applied Larsen SLC 1550 3mm self levelling compound, let it cure and then laid karndean on top. It looks fantastic. I am also now doing another room and I laid 15mm of the SLC again at the weekend on top of old concrete. My problem is that I have potentially been an absolute idiot as I failed to read the preparation part of the product and went straight to the installation section. I only read it after I mentioned to a friend what I had done and he asked if I primed the concrete first. So what I'm after knowing, is it absolutely necessary to prime old concrete first before self levelling or is that just belt braces? The old concrete was rough and I cleaned off any contaminants before I started. Am I likely to run into problems with this later down the line and if so how long can it take to shows issues? If I have to I will take up the latest 15mm section I did. It's not ideal but I will do it if that's how it should be done but the area I have laid karndean on is finished so I guess I just have to hope that will be ok? I guess what I'm hoping for is for someone to tell me I have been an idiot but it should still be ok! How long would it take to find out if the SLC worked and was keyed to the original concrete. any signs to look out for? Really appreciate any advice if possible.