Repairing Your Crumbling Concrete Walls

Home Exterior Maintenance: Repairing Your Crumbling Concrete Walls

Cracks in your concrete walls? Notre Dame Castle can help!

If your home’s exterior concrete walls are crumbling or cracked, then it’s not a moment too soon to take action. Cracks in your outdoor cement walls can lead to bigger problems – you don’t want water seeping into your basement walls, creating mould, mildew and rust.

Most houses shift over time, and together with fluctuating and extreme temperatures, this can cause the cement to crack and break down, so it’s a good idea to regularly monitor your home’s exterior walls.

There are many solutions on the market, each designed for specific surfaces, vertical or horizontal as well as different sized cracks and holes. Always follow the cement repair product manufacturer’s recommendations for best results and wear protective equipment to prevent injury or illness.

Weather conditions and outdoor temperatures play a big role in how well the concrete repair material will stick to the surface and cure. Fortunately, most concrete repair products are waterproof.

The key to success is to make sure you prepare the repair site properly before starting to patch up the cracks and crumbling cement.

Tools you will need to repair cracks in walls:

• Concrete repair product (see options below)
• Screwdriver or chisel and hammer
• Putty knife
• Wire brush
• Vacuum cleaner
• Spray bottle
• Container for mixing
• Trowel

Concrete Repair Products

Your best option for filling narrow cracks is a liquid concrete product as it will easily work its way into the crack. If your crack is a bit wider (up to ½”), a patch or concrete product will be best. Concrete mix or quick-setting concrete products are most effective for bigger holes and cracks.

Hydraulic Cement – Long lasting and durable, hydraulic cement is an efficient and cost-effective solution to repair cracks in walls. You will need to work quickly as it can set in a few minutes, expanding to fill the holes and cracks completely. You can purchase either a mix-it-yourself-with-water product or a ready-mixed product, usually a mixture of cement, gravel, and sand. Tip: an advantage of mixing your own is the ability to create the thickness you need.

Quick-Setting Cement – This concrete repair product takes a bit longer to set, usually 10 to 20 minutes. First apply a concrete bonding adhesive to ensure that the repair cement will bond strongly to the wall or other surface.

Make sure you wear work gloves when using quick-setting cement.

Concrete patch comes in vinyl, epoxy or acrylic, is pre-mixed and ready-to-apply, or you can buy the dry powder to mix with water. A great choice for blending in with the concrete colour, this repair product won’t shrink or crack. It is also Volatile Organic Compound (VOC) compliant. Made with polymers and additives, it’s more flexible so it adheres well. Use a putty knife or trowel to smooth the edges around cracks.

Concrete super patch is ideal for repairing vertical or horizontal concrete, brick, masonry and stucco walls. This repair product comes in exact amounts of powder and liquid that you will need to mix together.

Concrete repair caulk comes in a tube so it’s perfect for very thin cracks on vertical or horizontal surfaces; you simply apply with a caulking gun. It comes in a range of colours to match your grout or cement. You can apply it in layers, waiting for each layer to dry thoroughly.

Concrete sealant is a good choice for repairing small cracks on horizontal surfaces. You can add thin layers gradually to build up deeper cracks.

Best product for thin cracks in concrete – Try an epoxy-injection liquid concrete repair system for thinner cracks.

Best product for crumbling concrete edges on steps – Combine quick-setting cement with an acrylic fortifier to easily sculpt the shape you want for your step’s edge.

Interior basement wall cracks – If you find that your interior basement walls are cracked and water is leaking through, you can use a hydraulic cement water stop product. This putty is a great option because it expands gradually to fill the crack snugly.

Method for Cement Repair and Patching

Step #1 - Start with a clean, dry surface
To ensure success, remove any debris or loose concrete from the crack. After digging out any loose concrete and smoothing the surface with a wire brush, you can also vacuum the crack to get rid of dust that could impede the repair process. Another option is to spray water from your garden hose to remove loose grit. Leave enough time for the cracks and crevices to completely dry as any moisture will prevent your repair work from properly sealing.

Step #2 - Dampen the surface
After waiting for the cleaned-out crack to dry thoroughly, you will need to dampen the hole and the surface around it with water from a spray bottle.

Step #3 - Mix the cement with water
Using a putty knife, mix the cement with water in quantities small enough to repair each crack, one at a time, to prevent wasting the cement. It hardens very quickly! Your mixture will be ready to use when it has a thick spreading consistency.

Step #4 - Fill the crack
You will need to work fast to fill the crack with the cement mixture using a putty knife. Smooth it out before it dries and hardens.

Step #5 - Spray with water
Now lightly spray the repair with water five to ten times over the next 24 hours, if directed for the specific product you are using.

Allow 48 hours for your cement repairs to cure.

Fall is a great season to do your exterior wall repairs, but if you have noticed leaking or damp walls, it is best to take care of it right away. Aim to repair your outdoor walls when there is no rain in the forecast and when it is not too hot and humid or in freezing temperatures.

If you have any questions or need more information, feel free to visit Notre Dame Castle for assistance. We would be happy to help you in any way we can.