Crack Repair FAQ’s
Q: How can I tell if the crack needs structural repair?
A: If you think you have structural issues, call us at The Foundation Expert immediately! (877) 344-1155.
Signs of structural cracks include horizontal cracks, cracks 1”or greater, significantly wider at the top than the bottom, and offset cracks. These are just a few signs of structural damage. If there is any question of structural problems, we’ll know when we have inspected; and if so, call the engineer on duty to develop an Engineer’s Report, necessary for anything ‘Structural’, to pull the appropriate permits, to have an engineer’s stamp of approval, which will be critical if you ever need to sell your home. Don’t make a mistake by going with a company which does not understand the difference between structural and non-structural foundation problems. You don’t get any ‘do-overs’ with your foundation. Rely on engineering, not contracting in this case, The Foundation Expert – Licensed Structural Inspection to evaluate your situation.
Q: When do cracks in concrete occur?
A: Some, right away, some within 7-28 days of when your house was built. Many poured concrete cracks develop within the first two years after the foundation walls are poured. Block can take much longer – twenty, thirty, fifty years? Longer.
Q: Can a crack in concrete grow?
A:Yes. Freezing, thawing, pressures from expansive soils and seasonal and daily changes in moisture content within the soil surrounding your home; just a few of the reasons that cause cracks in concrete to grow or move.
Q: Does a crack in a concrete wall that is not leaking need repair? I am going to finish my basement and am concerned about ruining my renovation; ruining my material possessions, carpet, furniture, boxes, musical instruments, clothes, etc.
A: Cracks will continue to deteriorate over time due to continued settling, poor drainage and hydrostatic pressure, moisture penetration, and soil pressure against walls. It is recommended that all cracks be repaired prior to finishing a basement or storing valuable items there.
Q: How does crack injection work?
A:Sometimes a completed two-part application in one tube, or a two part liquid resin through a double barrel tube gun, which is then pumped to flow, under low pressure, into the crack in the wall from inside the basement through ports. This resin, or epoxy, or polyurethane 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 or hydrophilic reacts chemically with the water, and then solidifies filling the space within the crack. The ports can be easily removed by hacksaw or other tool.
Q: How long will a crack injection repair last?
A:It depends on who does the injection. When we do crack injection, it is done properly and should last at least 10 years, but we double proof our crack repairs with Miradrain drain board run up on either side and directed either under the floor into something existing there, or we might have to install a sump pump or more. The repair might last longer, depending on the
extent of the solution. Some companies have “life of the structure” guarantees or warranties – who are they
kidding? The structure might last 100 years, while companies come and go. There are no “guarantees”, just warranties, which are different, and that is the truth. I’ve been testing, inspecting, and building foundations in Baltimore, Maryland, District of Columbia, and Northern Virginia since 1973 and aside from commercial projects (like the Pyramids – not my project, either), nothing is lasting more than 200 years in this country.
That is what we are encountering on occasion, something 200 years old, but more homes that are 1/5 that, around 40-50 years old, before it starts to fall apart. Without maintenance continued along the way. But in the poorer parts of town, where maintenance costs were too much, those residences are truly crumbling after 100 years; newer homes in sub-divisions built like Tinker Toys, around 60 which gives them about 25 more years. Life of Structure sometimes means life of the corporate structure which doesn’t seem to last very long with most ‘waterproofers.’ Please be aware. I am also seeing homes with foundations which are failing after 40 years.
We at The Foundation Expert are not perfect (although we sometimes think we are). We think that our system is practically fail safe. I don’t predict or warrant against earth shaking conditions. But you do get a warranty. Depending on the type of crack, and the solution you agree to, will determine our warranty. The Foundation Expert will give you a free labor and materials warranty from 5-10 years to our Lifetime Warranty, which is “as long as you own the home or transfer to next owner with warranty period”. The length is determined by how extensive the solution. How old your place is. We do have permanent solutions, which can last forever, some solutions will cost you much more, some are more complex than an interior injection.
Q: When fixing a crack, what is the difference between an epoxy application and a polyurethane application? Can you be more specific – when would you apply one or the other?
A:The answer is not as simple as the question. Either material may achieve the desired result with some cracks, and with others, it is definitely one or the other. Some companies doing the application may simply choose the material they have the most experience with. If a specific crack needs to be repaired only to prevent water seepage, or water is actively seeping through the crack, we usually will apply polyurethane hydrophilic foam; whatever we feel is the best choice. Here is a breakdown of when we might use epoxy or polyurethane:
Epoxy is available in a wide range of viscosity, from ultra-thin to paste-like, which can accommodate cracks of different widths. If we determine that we are going to use epoxy (we prefer Polyurethane when this fix will work), we will use whatever viscosity is necessary to inject a given crack at pressures less than 40 psi. The width of the crack will determine the viscosity. A wider crack
requires thicker material.
The main advantage to using epoxy is the amazing compressive strength, which at 12,000 psi or greater exceeds that of most concrete. This is why epoxy is sometimes the better choice for repairing structural cracks. However, epoxy can cure very slowly, usually taking hours to harden and cure. This can be advantageous since it allows time for the epoxy to flow into even the smallest crevices.
On the flip-side, if the backfill outside the wall has separated from the foundation, creating a void, the epoxy may flow out of the backside (outside) of the crack before it has properly cured or hardened. This can happen as a result of settlement, poor compaction during construction, materials thrown into the backfill instead of soils, and erosion do to the water. This may be why the crack is leaking water in the first place – it is the path of least resistance! Also, epoxy might fail in a wet application, although we always ‘torch’ the bare wall with butane torches.
These elastomeric, fast-setting foams are effective alternatives for applications involving only crack sealing (waterproofing) and not structural repair. If we have a concern about material leaking out the back of a crack, if we determine during our material testing and application process that epoxy is indeed flowing out the back, we then turn to polyurethane foams.
Because of their elastomeric nature, they are able to accommodate slight concrete movement so the seal stays intact. They also begin to harden and foam within minutes of injection. This reduces the chances of the material flowing out of an injected crack while still in liquid form, and even if some does leak out, the foam will fill the void. Although they do not add any compressive strength, you usually do not need any.
Q: What is the best repair method for a cracked poured concrete basement wall?
A:Go outside and dig down, way down to foundation footing. Then seal the outside. Then go inside, and inject a low pressure epoxy or polyurethane – whichever we think is the best method, the best application based on what we see when we arrive, not diagnosed on the phone. 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 urethane foam, you will fill any void behind the crack.
Q: Why do surface repairs using hydraulic cement, caulks, coatings, or patching always fail?
A: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 the cracks movement 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.
Q: What if the crack is very small?
A:Not so small you’re not reading this question. It is rare that a crack is so small it cannot be injected with a crack injection system. Cracks, which are barely visible to the naked eye, are good candidates for crack injection. Again, visual confirmation.
Q: Why does concrete crack?
A:See Causes and Solutions. Cracks in concrete are a result of shrinkage during cure and other construction practices when the house is built. Settling, structural overload, soil shrinkage and expansion / swelling, hydrostatic pressure due to poor drainage, and other factors. Almost all concrete poured basement walls will eventually develop cracks.
Q: What is “stapling” a crack and how important is it?
A: Stapling is the process of installing carbon fiber with or without Kevlar™ reinforcements on the wall across the crack that is being injected with epoxy or polyurethane. In my opinion, the jury is out. I can’t see these staples holding the forces of any crack, if the water wants in. The carbon fiber strips and / or staples are installed with epoxy securing them in place. This reinforcement procedure again in theory, and so far in practice, but we’re talking years here, not decades. I measure geologically for every 20 years. Soil naturally compacts in 20 years to a pan hard surface, in sufferable to or with water to building, and completely differenct from when the construction took place. Staples may prevent 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 because of a crack that may or may not be structural. It’s all conjecture unless a physical inspection is performed. The carbon fiber or carbon fiber with Kevlar may significantly improve the structural strength of the concrete where it is needed. Iron beams work.
Q: 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 $10,000+ – ten thousand dollars to keep my basement dry?
A: Maybe. Maybe not. We can’t possibly know how much until we visibly see how much needs to be repaired by our observations and calculations. We don’t estimate – we quote exact prices and conditions. If all you have is a crack (poured concrete), and no seepage at the cove (where the floor meets the wall) then probably not. At least, not spend $10,000. However, if the crack was caused by hydrostatic pressure (not an easy determination), then a drainage system may be the solution, along with proper crack repair. Only a qualified inspection will allow us to make a determination for sure. Call The Foundation
Expert at (877) 344-1155 for a qualified concrete crack repair consultation and possible inspection.
Q: Will a low-pressure injection work on my cracked block foundation wall?
A: No, blocks are hollow and porous. We can recommend alternate methods of repair. Block walls that leak are serious. Moisture soaking through is serious, but if you have a crack in a block wall, and water is coming through, you may have a serious issue. Call us.
Q: Do you recommend injecting the leaking joint between my poured wall and the concrete slab?
A:No. You need a sub-floor, drain tile system if the floor cove is leaking or seeping water. If you already have a drainpipe system installed by the original builder or another waterproofing company, and it is seeping in that area, then the drain tile is clogged, or blocked, or the sump pump is not working properly. Regardless of your situation, The Foundation Expert can properly diagnose and prescribe a cost effective solution to your problem.sam@theFoundationExpert.com or (877) 344-1155