Patching_Holes

Patio_Bricks

Asphalt

A.  General Information
        Concrete is one of the most durable building materials. Concrete is normally the first step at the beginning of any building project, so a level surface is always important. Concrete has a wide variety of purposes, and comes in a variety of mixtures to suit. Used correctly, concrete will last just about forever. It's cost effective for almost any situation, can be shaped in almost any form, can be painted or textured to create almost any appearance, and can hold firm almost any object. Concrete work does take a lot of experience, make no mistake about it. But, you can learn the basics easily if you have some trade-sense.

B.  Concrete Problems
        Although concrete seems indestructible, it does need some occasional repair and maintenance. Problems can come from outside forces, improper finishing techniques, or faulty materials. Whatever the cause, you should address concrete problems as soon as you notice them so there won't be further damage that will be impossible to fix. The two general types of concrete problems are structural failure, which is usually caused by outside forces like freezing water, and surface damage, which is usually caused by improper finishing techniques or badly mixed concrete. In cold climates, it's common to have frost heaving, which is when the freeze-thaw cycle forces concrete slabs out of the ground. The best solution is to remove the affected sections, repair the subbase, and pour new sections separated by isolation joints. Sunken concrete is usually caused by erosion of the subbase. Some structures like sidewalks can be raised to repair the subbase and then relaid. A better solution is to have a contractor raise the surface by injecting fresh concrete below it. Isolated cracks are common in concrete. Fill small cracks with concrete caulk or crack-filler, and patch big cracks with a vinyl-reinforced patching product.

C.  Concrete Maintenance & Repairs
        Regular cleaning keeps concrete from deteriorating when exposed to oils and deicing salts. To clean oil stains, dampen sawdust with paint thinner and apply sawdust to the stain. The paint thinner will break apart the stain and the sawdust will absorb the oil. When you're done, sweep up sawdust with a broom and reapply as needed. To paint concrete surfaces, use a waterproof concrete paint made to resist chalking and efflorescence (the dusty film caused by mineral leaching). It's sold in stock colors, but you can order custom colors, too.

        In concrete sidewalks and driveways, use concrete repair caulk to fill the control joints. The caulk keeps water from damaging concrete. To keep aggregate from loosening, apply an exposed-aggregate sealer about three weeks after you pour new concrete. First, wash the surface thoroughly and let it dry. Pour the sealer into a roller tray, making a puddle in the corner. Spread the sealer evenly with a paint roller on an extension pole. To protect concrete that's exposed to traffic or moisture, seal it with a clear concrete sealer, which creates a water-resistant protective layer on the surface. To improve appearance of a concrete wall, you can use a masonry recoating product. They're applied like paint, and look like fresh concrete when dry, but have little waterproofing value.

Patching a small hole
        Start by cutting around the damaged area with a masonry-grinding disc mounted on a drill or a cold chisel and a maul. Bevel the cuts about 15 degrees away from the center of the hole. Chisel out any loose material within the repair area. Using a paintbrush, apply a thin layer of bonding adhesive to the entire patch. Fill the damaged area with a layer of vinyl-reinforced patching compound, adding no more than ¼" to ½" at a time. Wait about 30 minutes between each layer to let compound dry. Continue adding ¼" to ½" layers to the hole until it's filled to a level just above the surface of the surrounding area. Use the trowel to feather the repair area until it's level with the surrounding surface, then let the patching compound cure.

Patching a large hole
        Start by marking lines around the damage. Cut on the lines, using a portable circular saw and a masonry cutting blade. Set the foot of the saw on a thin board to protect it. Bevel the cut away from the damage at a 15 degree angle. Chisel out any remaining concrete in the repair area. Brush a thin layer of bonding adhesive onto the patch. Mix sand-mix concrete with acrylic concrete fortifier. Trowel it into the hole, adding no more than 2" at a time. Let concrete dry between layers. Continue adding concrete until it's just above the level of the surrounding area. Smooth and feather with a screed board and a wood float until it's level with the surrounding surface. Re-create any special finish that was used on the original surface (such as brooming), and let the concrete patch dry.

Patio Bricks
        Freezing and thawing cycles can cause the ground to shift, heaving the bricks in your patio. If this happens, you should remove the displaced bricks and create a level surface underneath. These steps can also be used to fix brick walkways. Remove any bricks that are dislodged or uneven. Add or remove sand as needed so the base is level with the surrounding sand. Smooth the sand with a garden rake. Water the sand thoroughly, then pack it down with a hand tamp. Replace the bricks in the patio, laying them tight against each other. Set the bricks in the sand by tapping them with a rubber mallet. After a few bricks are set, use a long level to check that they are flat and flush with adjoining bricks. If any changes are needed, just add or remove sand, or tap high bricks deeper into sand and keep checking for level as you set bricks. Spread a thin layer of sand over the repair area and work it into the joints between bricks, then sweep up loose sand. Spray the area with water to settle sand in the joints. If needed, spread and pack more sand until all joints are tightly packed.

Asphalt
        Asphalt is usually damaged by heavy wear, repeated impacts, and water penetration. If you find a hole, it's best to attend to it as soon as possible because a single hole can lead to deterioration of the gravel base and then the asphalt itself. To patch a hole in asphalt, start by cleaning the hole. Use a shop vacuum to get all dirt and debris from the area. Flush the hole with a hose fitted with a spray nozzle. Then pour asphalt patching material into the hole, slightly overfilling it. Warm it with a heat gun. Use a trowel to level and smooth the patch. Cram the patching material with a heavy brick or concrete block until it's firmly packed in the hole and level with surrounding surface.

        An easy way to give an old asphalt driveway a fresh, new appearance is an asphalt sealer. Before sealing driveway, inspect the surface carefully and repair any holes. Then, use an asphalt cleaning product to clean it and remove any oil and dirt from the surface. If surface isn't heavily soiled, you can use warm water and a mild detergent. After cleaning, rinse it off with a hose or a power washer. To patch any cracks in the asphalt surface, use a caulk gun and a tube of asphalt patching compound, slightly overfilling the crack. Spread and smooth patching material with a putty knife. To keep patcher from sticking to the scraper, dip the scraper in cold water or mineral spirits. Pour a pool of asphalt sealer onto one corner of driveway. Use a squeegee or a broom to spread it in a thin layer, following manufacturer's instructions, until the whole surface is coated. Don't apply a layer that's too thick because it won't cure properly. Apply more than one coat if you want a heavier layer of sealer. Let sealer cure thoroughly before walking or driving on it. Block the entrance while the driveway is drying out.