Frequently Asked Questions: Repairing Foundation Cracks
What is the best repair method for a cracked poured concrete basement wall?
A low pressure concrete crack injection using either epoxy or polyurethane resin is the best method. While there are numerous ways to temporarily patch cracks, to get a permanent repair you must do two things: stop moisture penetration from the outside and eliminate or accommodate any wall movement. Low pressure injections are done from inside the basement. The procedure will fill the crack from front to back and bottom to top thus completely sealing the crack. In addition, when using polyurethane foam, you will fill any void behind the crack.
Why do surface repairs using hydraulic cement, caulks, coatings or patching always fail?
These types of repairs consistently fail within a short amount of time. Expansion and contraction movement of the wall, though minimal, causes these repairs to shadow crack and leak again. Low pressure urethane and epoxy grout injections are permanent repairs since the crack within the wall is completely filled, not just the surface.
How does crack injection work?
A two part liquid resin is allowed to flow under low pressure into the concrete crack in the wall from inside the basement. This resin is introduced into the crack through small ports glued over the crack. The resin travels all the way through the wall to the outside where the concrete wall meets the dirt. The polymer chemically reacts and then solidifies filling the space within the crack. The ports can be easily removed in a day or two.
How long will a crack injection repair last?
Crack injection when properly installed will last the life of the structure.
When should epoxy be used and when should urethane be used?
Both polyurethane and epoxy can be used to stop water. Polyurethane foam has the advantage of expansion allowing for filling potential voids both within and beyond the wall. Expansion also prevents the product from leaking out of the crack before it cures and fills more thoroughly. Repairs that are structural require the use of epoxy.
How can I tell if the crack needs structural repair?
Signs of structural cracks include horizontal cracks, cracks ½” or greater, significantly wider at the top than the bottom, and offset cracks. These are just a few of signs of structural damage. If there is any question of structural problems an engineer or a professional repair contractor should be called.
What if the crack is very small?
It is rare that a crack is so small it cannot be injected with Emecole’s crack injection system. Cracks which are barely visible to the naked eye are good candidates for crack injection.
Why does concrete crack?
Cracks in concrete are primarily due to shrinkage during cure and other construction practices when the house is built. Settling, structural overload and earthquakes are other examples. Almost all basements will eventually develop cracks in a wall.
When do cracks in concrete occur?
Most cracks develop within the first two years after the structure is poured.
Can a crack in concrete grow?
Yes. Freezing, thawing, pressures from expansive soils and changes in moisture contest in surrounding areas are a few of the reasons that cause cracks in concrete to grow or move.
Does a crack in a concrete wall that is not leaking need repair?
Cracks will continue to deteriorate over time due to moisture penetration and soil pressure against the foundation. It is recommended that all cracks be repaired prior to finishing a basement or storing valuable items there.
Will low-pressure injection work on my cracked block foundation wall?
No, blocks are hollow and porous. A local basement waterproofing applicator can recommend alternate methods of repair.
Do you recommend injecting the leaking joint between my poured foundation wall and the concrete slab?
No. The floor cove should not leak unless the drain tile is blocked or the sump pump is not working properly. Occasionally short distances along the cove are injected with urethane to hopefully divert the water back into the drain field. This is assuming that the drain tile is not blocked.
Why would I spend more money for staples when both the other contractor offers the same warranty?
Many contractors use injection by itself for repairing foundation cracks. Another contractor wants to inject and use carbon fiber countersunk staples. Both contractors offer a guarantee on their work. Crack injection became less expensive with the introduction of dual cartridge tube sets, dual dispensing guns, etc. However it also became too easy. Everyone with a pulse began shooting cracks with some kind of sealant.
What is stapling a crack and how important is it
Stapling is the process of installing carbon fiber countersunk staples on the foundation wall across the crack that is being injected with epoxy. The carbon fiber staples are installed with epoxy securing them in place. This reinforcement procedure prevents the foundation crack from ever breaking again, even when the ground freezes and pushes against the wall. It is the preferred choice of repair when structural factors are believed to be cause of a crack. The carbon fiber significantly improves the structural strength of the concrete where it is needed.
I have two vertical cracks in a basement wall and I’ve been told I need a complete drain tile system. Do I have to spend thousands of dollars to keep my basement dry?
Run, don’t walk, to your phone and call a qualified concrete crack injection applicator for an estimate, it you have a poured concrete wall and not a concrete block wall.
Poured wall companies, when they are slow, will pull a guy off a crew and send them out for warranty repairs. Find a contractor today that doesn’t offer a warranty and ask yourself if you think they’ll still in business 2 or 3 years later after the repair fails.
Very few crack repairs fail immediately. It is long-term creep and fatigue of material injected with the movement of foundation that can fail over time. By cross-stitching crack repair with staples this creep is eliminated and improves long-term performance of repair material. Think in terms of 3 roof repair options giving a 10 year, 20 year or 30 year warranty vs. the cost for quality.