How to prepare concrete for an overlay or resurface.

When the surface of concrete is severely damaged, and there is no small repair that can remedy the problem. Deciding to resurface the concrete is the most inexpensive and affective way to achieve your desired results. I recommend using an experienced contractor for the installation. Many overlay products have been introduced over the last ten years. Many have failed in durability. Some times the product is to blame. Most of the time, overlays fail do to the installation. Some product companies require contractors to be trained and certified in order to do buisness. Ask your contractor if he is certified to install overlay products. This will save you in the long run for overlays are very sensitive and yield a low margin of error. There are resurfacing products at you local HD and hardware store. The results will be rough, but you will save money. This article will cover basic preparations required to prepare a concrete surface to be resurfaced. This will be the outdoor application. By following these steps, you eliminate 60% of the margin of error. You will also ensure a good bond and longer life.

Instructions

Difficulty: Moderately Easy

Things You’ll Need:

• 3700 psi pressure washer
• floor buffing machine
• wide broom
• muriatic acid
• ammonia
• chemical gloves
• eye protection

1. Start by wear eye protection and pressure washing the entire slab. Keep the tip close to the ground in order to blast out any loose sand and grit. Also, pressure wash close enough to remove the top, thin layer of concrete.
2. Wear chemical resistant gloves and eye protection. Dilute muriatic acid 2:1. Thats 2 gallons of water to every gallon of acid.(1 gallon of acid mix will yield about 10 square feet) Pour small amounts and spread around with a broom. Make sure you cover the entire slab evenly with acid mix. The concrete will start to fizz. (like peroxide on a wound) Let the concrete fizz for about 15 minutes. Do not let the acid dry on the slab.
3. With the water hose, flood all the acid off the slab. The water will dilute the acid making it less potent and harmless.
4. If there are any holes larger or deeper than half inch, you should fill them in will some mortar and let it dry. If there are no major repairs or anything that will bother you looking at it, proceed to next step.
5. With the floor buffer, Use 60 grit screens to sand any loose stones, bumps or small peaks that will interfere in the resurface. The acid treated concrete will be softer, making it easy to sand.
6. Wear gloves and eye protection. Dilute ammonia 4:1. Thats 4 gallons of water to 1 gallon of ammonia. Pour and spread it all over the slab. This will neutralize the pH of the concrete. Be sure to scrub the concrete dust that tends to stick to the surface as it drys. Keep the slab wet.
7. Use the water hose to rinse away the ammonia and dust mix. It is vital to scrub away any dust or debris off the slab. In a resurface, a grain of sand is enough to complicate the installation. Rinse slab until it is 99.5% dust free.

Tips & Warnings

• All overlays should be prepared in the same way to ensure a good bond.
• Using a certified installer is recommended.
• All overlays are applied differently.
• Keep surface clear until overlay is applied.
• Read all labels on chemicals to take precaution.