Written by Sherrill Dean Teaster and Keith Potts | ©2016, Mr. Sponge Waterproofing, Inc, All Rights Reserved | No unauthorized duplication of this article without written permission.
Written May 4th, 2016
A Scientific solution for a common basement rod hole leak
The common tie rod hole problem has been an issue for homeowners during the last 5 decades that have resulted in flooded basements, lost items and costly repairs. The tie rod hole problem has never been fully understood and explained. These leaks have often been incorrectly diagnosed as a failed foundation drain tile systems, or an unexplained leak source that results in high repair costs. Not fully understanding a tie rod hole leak is a common cause in homeowners paying for unnecessary and mis-diagnosed repairs. This article is written to help homeowners understand what a tie rod hole is and how to make proper repairs. In this article, we will introduce the latest scientifically designed water activated swell plug specifically designed to solve this condition.
The conventional forming system of concrete walls utilizing tie rods
The following description supports understanding the condition of leaking tie rod holes left from foundation forming systems that use 5/8 (15.88 millimeters) reinforcement rods. Tie rod holes are also commonly referred to as pinhole leaks, rod pocket leaks, and tie backer hole leaks in other regions of the United States. After the foundation wall is poured and cured, the supporting tie rods are removed along with the wall forming system, thus leaving the 5/8” holes in the poured concrete wall. Some newer forming systems use snap ties instead of tie rods to hold the forms together. This snap tie forming method does not apply to this article. Conventional forming systems are made of wood forms while newer forming systems are made from aluminum or steel forms.
Poured concrete foundation walls begin with the construction of forms in which to pour the cement. These forms are erected from blueprint specifications to construct the foundation layout. For many years, these forms, or “shuttering”, have been constructed from wood that is held together by steel tie rods. These tie rods are situated approximately every eighteen inches (0.46 meters) and about five feet (1.52 meters) high from the basement floor across the entire basement. A second row is aligned vertically underneath and about one foot (0.30 meters) from the base of the floor. Basements higher than eight feet (2.44 meters) sometimes will have three rows aligned vertically. These forming systems will often utilize double tie rods at the corners of the foundation.
How a basement tie rod hole is formed
When a foundation contractor erects the forms in place, the tie rods are fastened and support the shuttering which holds the weight and the form of the foundation wall. Once the cement is poured, these forms are left a few days for curing. When that step is accomplished, the tie rods are removed allowing the shuttering to be dismantled. When this step is completed, you are left with a poured concrete foundation. The walls now have holes where the tie rods were that are approximately 5/8 inches (15.88 millimeters) in diameter. In this type of conventional forming system, the tie rods ”(are not)” left in the wall. The only time supporting wall forming ties are left in the wall is when a contractor uses a wall forming system that utilizes (snap ties). The photograph below shows the conventional wall forming method using wood forms and 5/8 inch (15.88 millimeters) forming tie rods.
New construction of a poured cement foundation
Close up new construction showing tie rod hole arrangement
Why tie rods leak after construction
After the wood forms are removed some contractors will apply hydraulic cement on the outside of the tie rod holes and/or spray a tar-based coating. Some contractors will use a spray foam insulation. These sealants will eventually break down and water will begin to re-enter the holes. Since pouring of foundations began, there have been varying attempts and methods to stop these leaks. Some methods will work for a few years while other methods fail quickly, such as cork and hydraulic cement. Some waterproofing contractors have applied a polyurethane caulk and cork method for a quick fix, but years later the leak still returns.
The leak returns because these conventional methods do not utilize a sealing system that reacts or co-exists with water. The introduced solution in this article is not affected by the following listed conditions that cause conventional bonding materials to fail. These common conventional sealing methods or products currently used bond up the tie rod hole that will loosen later due to:
- Delamination of the product/surface area. Delamination is a deformation of the concrete surface. When it is caused by moisture, this deformation is known as warping. Delamination is actual separation of the surface mortar from underlying concrete. It is hard to detect until it dislodges from the surface.
- Post materials left on the concrete surface such as release agents (calcium stearates) can inhibit long term bonding of sealants. Further, conventional forming systems such as described here consisting of course wood like plywood or dimensional lumber require a more reactive type of release agent, and typically requires a heavier material application rate of eight hundred to one thousand square feet per gallon or twenty to twenty five square meters per liter.
- Neglecting to seal. In most cases, the entire tie rod hole is left hollow with only the ends covered in porous hydraulic cement. This will be explained further in this article.
- Therefore, in cases of foundations formed with conventional course wood or dimensional wood forming (shuttering), more release agent will be left on the surfaces of the walls that will inhibit long term product seal with concrete surfaces as well as cases of deformation of the surface that allow bonding/sealing materials to dislodge, and finally, neglecting to seal.
The photograph below shows the soil side of a foundation wall after a conventional waterproofing material has been applied. As mentioned above in case (3), hydraulic cement has been applied over the open tie rod hole, then a spray coating of tar-based material is added.
The soil side of the foundation wall during construction
Revealing the tie rod hole from inside
In most regions of the United States the interior surface of the poured foundation wall is also coated with the same trowel applied hydraulic cement to fill in the (end) of the tie rod hole, then it may be sprayed over with a white stucco type finish. Older homes material may be a mixture of Structo-lite and Autoclaved Lime. New products on the market being used today by contractors are similar to EmeKote 100 Basement Wall Coating. Some builders will not apply this coating which makes it easier to see the location of the tie rod holes. In this case where the white coating is sprayed on, they are harder to see until they begin to leak. The removal of the trowel applied hydraulic cement on the inside covering the tie rod hole reveals the open tie rod hole going all the way to the outside of the basement wall where the opposite end is covered with a hydraulic cement cap. The photograph below shows the resulting condition thousands of poured basements have. In most cases, this is the only applied sealant at the time of construction.
Removal of the hydraulic cement reveals an open tie rod hole
Tie rod hole leaks can cause a lot of water damage in basements
When tie rod holes begin to leak they can flood and destroy a finished basements drywall and carpeting. Tie rod hole leaks have commonly been mistaken as drain tile failure. Due to the amount of water that can enter a basement it is understandable how this can happen. In some cases the leak is hard to detect since the water coming from the tie rod hole will dry on the wall only leaving the evidence of a puddle on the floor with no traceable point of origin. The photograph below shows how (one) tie rod hole leaking can wash in soil from the exterior making it easy to trace. If you multiply two rows of tie rod locations every eighteen inches (0.46 meters), you can see why this problem is not only the most common basement leak, but also understand how big and potentially costly this problem is.
The damage from (one) leaking tie rod hole
The multitude of tie rod holes
Tie rod holes are often doubled at the ends of the wall just prior to the corner form
Amount of water entry from tie rod holes
Unsealed tie rod holes are entrance for termites, ants and other insects
Most tie rod holes become an entrance for insects as they use the hole and old cork repair material for a nest as well as being a direct entrance from the outside soil. The photograph below shows a tie rod hole that was exposed behind a 2 x 4 stud. The removal of the front hydraulic cement cap resulted in ants entering the tie rod hole.
The revealed path of insects, the basement tie rod hole
Repairing tie rod holes before finishing a basement
If a home owner is planning to finish their basement and it has tie rod holes, they should consider repairing all of them before the installation of the final wall covering. Leaving the holes unsealed will eventually cause future problems behind the drywall or paneling. Below is a photograph showing extensive drywall removal to repair leaking tie rod holes left unsealed when the basement was finished without proper repair methodology for tie rod holes.
Tie rod hole damage after a basement is finished
Snap ties and conventional tie rod holes
As this article has explained in depth, the conventional tie rod leak is from the forming systems used since the early 1950’s where hand made wood shuttering forms are held together by 5/8 diameter (15.88 millimeters) steel rods.
Newer forming systems incorporate a snap tie metal type holding device that is not removed when the forms are dismantled. Rather, they are snapped off and left embedded in the poured concrete wall. In this case, tie rod holes do not exist. When a snap-tie leaks, high-pressure injection of water-activated polyurethane is the latest proven method of repair. The photograph below shows what a snap tie looks like.
What a snap tie looks like
How to successfully repair tie rod leaks
The most advanced repair method for stopping water is the use of compressed swell plugs which contain polyurethanes that are water-activated. The TRX Compressed Swell Plug is the only product of its kind, this patented plug has been used for in-field repairs since 1996. The TRX was made available to the public in 2011.
Water-activated materials can co-exist in wet environments longer and more effective than conventional bonding materials such as hydraulic cement products, epoxies, or caulking. Exposure to moisture will activate the polyurethane body and fully expand over a three week period causing additional sealing pressure beyond the initial compressed seal gained from tightening. This repair methodology requires the use of proper eye protection until repair is complete.
The TRX Compressed Swell Plug
Time Elapsed Action of the TRX Reaction To Water
Locating the tie rod holes for repair
Most homes will have tie rod reinforcement holes every eighteen inches (0.46 meters) across the wall. Eight-foot high walls (2.44 meters) have two rows approximately one foot (0.30 meters) from the floor and the upper row is approximately five feet (1.52 meters) from the floor. Ten-foot (3.05 meters) high walls will have three rows with the first row approximately three feet (0.91 meters) high from the floor and three feet (0.91 meters) higher for each of the remaining two rows. Normally the upper and lower rows align vertically with each other. It is recommended observing the entire wall from a distance of five feet (0.13 meters) away after the location of the first tie rod hole leak. Viewing the wall in this method will help see the others as they may appear as a small extrusion or irregularity in the surface of the concrete.
Opening the tie rod hole for repair
Properly expose the existing 5/8 inch (15.88 millimeters) diameter tie rod hole to a depth of three inches (76.20 millimeters). Use a standard hammer by rapping on the area until the 5/8 inch (15.88 millimeters) hole is fully exposed and the edges of the hole are hammered away to a beveled edge. In most cases the front of the tie rod hole will have a ¼ inch (6.35 millimeters) to 1/2” inch (12.70 millimeters) cosmetic covering of concrete. Take a standard screwdriver, dowel rod, or a tie rod bar to finish exposing the hole to a three inch (76.20 millimeters) depth. If necessary, the area may need to be drilled out using a 5/8 inch (15.88 millimeters) masonry bit. If the tie rod hole has been repaired before, it will be necessary to drill the hole out using a 5/8 inch (15.88 millimeters) masonry bit. After properly exposing the tie rod hole, remove any debris in the tie rod hole by flushing out with clean water or vacuuming.
Sealing the tie rod hole
Insert the blue end of the compressed swell plug into the exposed tie rod hole and hand tighten by turning the coupler end. Once snug, lightly tap the end of the coupler with a hammer until the coupler is flush with the wall. Finish tightening to a snug fit with a 3/8 inch (9.53 millimeter) socket or a 3/8 inch (9.53 millimeter) nut driver. Do not over tighten as it may cause the compressed swell plug to spin or fail. The repair can be left as is or covered with a suitable hydraulic cement or comparable masonry product that can be found at home improvement stores.
Sealing with the new TRX Compressed Swell Plug
When not to use
The TRX® Compressed Swell Plug is not designed to be used when the tie rod reinforcement hole has a wall crack located through the hole, nor is it designed to be used when the tie rod reinforcement hole is located within a honeycomb area of concrete (where excessive aggregate has cured in a given area causing see page through the aggregate). The TRX® Compressed Swell Plug cannot be used on Snap ties. Snap ties are small metal bars in the concrete wall that have been broken off. Sometimes this forming method is used instead of conventional 5/8” reinforcement rods.
When not to use in a honeycomb area
TRX Official Website
Save on expensive repairs by “doing it yourself”. Leaking tie rods are the most common leak in poured basement walls.
Video of repair technique using a TRX Compressed Swell Plug
One Minute Sell Ad Video for TRX Compressed Swell Plug
©2016, Mr. Sponge Waterproofing, Inc, All Rights Reserved
No unauthorized duplication of this article without written permission.
The TRX Compressed Swell Plug is not designed to be used when the tie rod reinforcement hole has a wall crack located through it, nor is it designed to be used when the tie rod reinforcement hole is located within a honeycomb area of concrete (where excessive aggregate has cured in a given area causing seepage through the aggregate). The TRX Compressed Swell Plug cannot be used on snap ties. Snap ties are small metal bars in the concrete wall that have been broken off. Sometimes this forming method is used instead of conventional 5/8 inch (15.88 millimeters) reinforcement rods.
This condition of rod holes in foundation walls is not the fault of the foundation contractor. The holes are created from the forming system. When they leak, it is the result of waterproofing sealants failing years after being initially applied during construction. In our opinion, foundation contractors make every attempt to seal the rod holes with their current sealing techniques in accordance to state regulations of dampproofing or waterproofing. Unfortunately, over the years these sealants do break down and result in leaking rod holes.