Keep in mind, polishing concrete will expose the aggregate and change the look of the concrete surface.Īnother option for smoothing a rough concrete surface is to apply a skim coat. This won’t smooth the surface to the glass like finish that the wet polisher will but it will give the concrete a nice honed finish. This means they don’t require such a high RPM and can be used on a regular palm sander. These are not diamond in resin like the wet polishing pads, they are electroplated diamond discs. They start with a fairly aggressive 60 grit and go up to 200 grit. Wet polishing can be messy so some people opt for a dryer option, like our Diamond-Discs. You can continue to polish higher but keep in mind that some stains and sealers won’t adhere to highly polished concrete. Usually you will go up to at least 200 grit. You would begin with the lowest grit necessary and work your way up. The first and most common method is to grind and polish using a wet polisher and diamond polishing pads (and possibly a diamond cup wheel, depending on the severity of the imperfections). There are several ways to repair rough/uneven surfaces.
SKIM COAT CONCRETE COUNTERTOPS HOW TO
We’ve talked about the problems, now let’s talk about how to fix them. Your options are more limited in this situation. If you happen to miss a spot, you will probably need to repair. It’s important to be mindful about this and fill in any low areas while the concrete is still very wet. Sometimes, when you vibrate the edges and the air starts escaping, the concrete can get lower in spots creating an uneven surface. This is done to push the concrete along your run and to ensure the concrete is level. When you initially pour a concrete countertop, one of your first steps is to screed. Possibly the most difficult surface to fix is high/low spots.
This is a liquid lubricant that is sprayed onto the concrete and/or the trowel itself in order to allow the trowel to glide smoothly over the surface and lessen the chance of imperfections. To help avoid this we recommend a product called Trowel Slick.
It’s understandable that having to use pressure can result in some trowel marks, especially for beginners. If the concrete is still too wet and the trowel slides and smooths the top easily without using pressure, it’s not yet time to trowel. It shouldn’t be easy to slide the trowel around, some pressure is needed to smooth out the surface of the concrete. The correct time to use the steel trowel is when the concrete is fairly set up. Trowel marks are also a fairly common issue with pour in place countertops. If you see this happening when you begin to sand, sand off the entire cream layer until you reveal the rough, gritty surface underneath. It can happen after a few weeks or even several months after being sealed however, it will eventually come up and need to be fixed. If this cream layer isn’t removed and the concrete is sealed, you will notice that the sealer will chip or peel very easily. When the concrete cures, it usually looks very smooth and attractive however once you start sanding, that soft, dusty “cream layer” easily sands away and you’re left with a gritty, rough surface. The trowel closes off the pores of the concrete so when this is done while there is still too much moisture in the concrete, the moisture gets trapped inside so it’s not able to evaporate properly. This happens when the concrete is troweled too early with the steel trowel. The most common reason people get a rough surface is due to laitance. It can usually be fixed and you have options as to how you want to go about it. Whether it be laitance, trowel marks, high spots, etc., there is no reason to panic. Many things can contribute to a rough surface on your concrete countertop. Let’s face it, our first attempt at troweling may not always be the smoothest. This image above shows a countertop that was steel troweled too early and left a soft dusty layer known as laitance.
DIY Concrete Countertops: How to Fix a Rough or Imperfect Surface
0 kommentar(er)
