How do pros waterproof concrete?
Professionals waterproof concrete by cleaning and repairing the surface, then applying specialized sealers or waterproof coatings. These products penetrate or coat the concrete to block moisture and stains. In some cases, cracks and joints are sealed with epoxy or polyurethane, and drainage improvements may be made to prevent water buildup and extend the concrete’s lifespan.
During your contractor’s visit, they'll likely start with a thorough inspection of the area, like your basement or foundation, to identify the source of the water problem. They’ll look for cracks or signs of water damage, and even take a look at the overall drainage around your property.
Once they understand the issue, they'll often suggest a waterproofing method, which could involve sealing the concrete, repairing cracks, or installing a drainage system. Finally, they should provide you with a detailed plan and a cost estimate for the project.
What are some signs that my concrete needs to be waterproofed?
You'll know it's time to get your concrete waterproofed when you see:
Water stains or puddles. If you notice damp spots, active leaks, or standing water on concrete floors or walls, too much moisture is getting in.
A white, chalky substance. This powdery residue, called efflorescence, is left behind when water seeps through concrete and then evaporates, leaving mineral deposits.
Damp or musty smells. A persistent earthy or moldy odor in your basement or garage often means hidden moisture and mildew growth.
Peeling paint or warped flooring. When moisture pushes through concrete, it can cause paint to bubble and peel or make flooring materials warp and lift.
What questions should I ask concrete waterproofing contractors?
Before hiring a contractor to waterproof concrete, here are some questions to ask:
Are you licensed, bonded, and insured for this type of work?
Can you provide references from recent, similar projects?
What waterproofing method and materials do you recommend for my situation, and why?
What is the estimated timeline for the project?
Will you provide a detailed written estimate that outlines all my costs?
Do you offer a warranty on your workmanship and the materials?
How will you protect my other property during the project, and what does cleanup involve?
What is the best sealer to use on concrete?
Because unsealed concrete is porous, it readily absorbs liquids, leading to unsightly stains and freeze-and-thaw cycle damage. For this reason, it’s important to seal concrete that will see spills or outdoor weather.
The best option for garage floors and other high-traffic areas is epoxy, which forms a hard and extremely durable surface on top of concrete. Epoxy, acrylic, and polishes are often used on indoor floors, while acrylic-resin sealers and reactive penetrating sealers are used on outdoor surfaces to repel water and salt. Locate a concrete contractor in your area to help find the best solution.
How will waterproofing contractors estimate the cost of my project?
Contractors will likely consider several things when estimating the cost of your project:
The size of the area. For example, a small concrete patio will cost less to waterproof than a large basement foundation.
The methods used. For example, applying a simple sealant is often less expensive than installing an exterior membrane or a full interior drainage system.
Your concrete’s condition. If there are major cracks or damage, the contractor will need to fix them before they can start waterproofing, which will add to the project’s cost.
How easy the area is to access. A project that requires excavation or work in a cramped crawl space may cost more because of the extra labor involved.
Labor rates. Rates for laber differ depending on where you live. A more complex job that takes more time or specialized skills will also increase the final price.
How should I prepare for concrete waterproofing?
Before concrete waterproofing begins, it's a good idea to take these measures:
Step 1: Clear the work area. The contractor will need unobstructed access to the foundation walls, basement, or concrete slab. Move any furniture, storage boxes, and personal items several feet away from the areas being treated.
Step 2: Make a clear path. There should be an easy-to-navigate route from the entrance to the work zone. This helps the team carry their equipment in safely.
Step 3: Address any standing water. If it's safe to do so, remove any minor standing water with a mop or wet vac. For significant flooding, let your pro know ahead of time so they can bring the right pumping equipment.
Step 4: Remove pets and children. A work site can have tools, materials, and chemicals. For everyone's safety, it's best to keep children and pets in another part of the house during the appointment.