concretefloorlevelingprimerslab
We have a slab foundation on our place. The previous owners put down carpet with pad and there's a fair amount of glue and pad residue on the concrete, as well as some paint overspray. We'll need to level the floor and roll on a liquid moisture barrier before putting down flooring. Two questions:
Do I need to grind off every bit of glue and stuff before putting on concrete leveler primer?
Thanks!
Type of flooring dictates how "perfect" it needs to be, carpet being the least work. Vinyl is flexible so just no real drastic changes.
Below are the basic steps to fixing uneven concrete floors.
Use a straight edge and mark high and low spots. (Really exaggerated case in this image)
Or if you like gadgets, Bosch has a new laser out that lets you easily mark the uneven parts.
You use a grinder (with dust mask and safety goggles) for high spots. You can rent a large floor grinder or get on your hands and knees.
and SLC (self-leveling compound) in low spots. For SLC just follow the manufacturer's instructions. If the floor is really bad you may want to pour the stuff over the whole thing.
If you don't have gutters and the grading around your house isn't sloped away, I'd start there. It's relatively cheap to do and will eliminate most problems. It's also nice, if you have a door at the bottom of a roof edge, to not enter under a waterfall.
Once you've done that (or if it's not possible to fix the grading) and the foundation is still wicking water, then an exterior water proofing system and french drain makes sense. This involves a painted on sealer, a free draining membrane that's attached to the wall (this gives a direct path for any moisture that reaches the wall to run directly down to the drainage pipe), and a perforated drainage pipe running around the perimeter of the foundation that drains well away from the house. If a system like this isn't installed during initial construction, it's often left to a last resort because of the expense and labor of removing any landscaping and soil that is against the foundation.
Best Answer
Assuming this is a floating vinyl floor (as originally posted), you need to scrape away the high spots, lay down an underlayment that has vapour barrier with foam and optionally felt to provide a smoothing cushion.
For planks, there's no need to prime or scrape bare.
As for flatness and smoothness, the manufacturer will specify it, but usually anything less than 1/16in is not a problem, and some bowing and bending over several multiples of the plank length or its width is tolerated quite well.
If you are flattening with self-leveling cement, for whatever reason, you have to scrape the concrete bare, entirely.
As for a concrete or cement primer, read the label on the self-leveling cement: some don't need primer and they are more expensive. Others require primer which you can add-in or roll-on to your surface.
Which one you choose depends a bit on how thick the layer will be: anything over 1/4 (very roughly) and it's more economical to roll it on first, otherwise you're just mixing very expensive cement.