Cracks form in concrete surfaces due to several factors, most common of which are the freezing and thawing of water as the seasons change, and wear and tear. The parts of the home that are usually affected by these are the patio, the driveway, and the basement.
If cracks appear in the basement, it is particularly important to determine if it is caused by the freezing and thawing of water as it can cause seepage and flooding when the crack gets large enough.
STEP 1: Assess the Crack
Before attempting any repair, a careful assessment of the crack should be made. To assess the risk that the crack poses, look at the size, the length, and width of the crack, the depth if possible, and look at the immediate area around the crack for signs of water damage or other structural defects.
For smaller cracks such as hairline cracks up to cracks around half an inch wide, DIY repairs are advisable. However, for larger or deeper cracks and cracks that are likely to affect the integrity of the structure, calling a professional is still the best course of action to ensure the safety of the building and its inhabitants.
STEP 2: Determine which method is best to use
Aside from being a good indicator of the level of risk to the structure, the size of the crack also determines what DIY repair method is best.
For small cracks with widths up to a quarter of an inch, using concrete sealants are advised. The most commonly used types of sealants are epoxy or urethane systems, acrylic resins, silicates, siliconates, and silanes.
Epoxy and acrylic resins have many similar qualities. They are generally affordable and easy to use, which makes them the top choice for minor repairs around the home. However, between the two, epoxy is known to be more durable and more water resistant while acrylic resins are more decorative.
Silanes, silicates, and siliconates are generally more expensive materials to use for repairs. The applicability of these sealants is typically based on the porosity or permeability of the cracked surface. Of the three, silicates are best to use for cracked basement floors. Aside from sealing and repairing the damaged floor, silicates help concrete appear more polished and finished. Siliconates can also be used on basement floors because of its general compatibility with concrete.
For cracks that are more than a quarter of an inch wide but not more than half an inch, a particular sealant known as a pre-mixed mortar is best to use.
For cracks larger than half an inch, store-bought concrete mix is best to use.
STEP 3: Clean the crack
Before starting with the repairs the cracked surface must first be cleaned to allow the sealant used to adhere to the concrete surface.
First, brush away and remove any dirt or concrete pieces in the cracked area. To make sure that no loose debris is still in the crack, use a pressurized garden hose to rinse away unwanted materials. Scrub the area with detergent if needed. Make sure that the cracked surface dries out before applying the sealant.
STEP 4: Repair
For smaller cracks, apply the sealant directly onto the cracked surface and use a metal scraper to smoothen and fill the crack. Make sure that the crack is fully filled. If any empty spaces remain after the sealant has dried, apply more sealant and repeat the process as needed.
For larger cracks that use pre-mix cement, mix the cement according to the instructions provided by the manufacturer. Fill the crack with the cement, and wait about an hour before scraping off any excess materials to smoothen out the surface.
STEP 5: It’s a waiting game
Wait for the sealant or the cement mix to dry. The amount of time it takes for the material to dry will depend on the amount and type of material used. The typical drying time spans anywhere from 24 hours up to 72 hours or 3 days.
STEP 6: Enjoy your crack free basement
After the repair, maintenance and monitoring are recommended to prevent more cracks from developing in the future.