The conventional forming system of concrete walls utilizing tie rods.
The following description supports the understanding of 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 constructing the foundation wall, these tie rods are removed with the wall forming system, leaving holes in the poured concrete wall. Some newer forming systems that use snap ties instead of tie rods to hold their forms together do not apply to this article.
Poured concrete foundation walls begin with the construction of forms in which to pour the cement. For many years, these forms called shuttering have been constructed from wood that is held together by steel rods called tie rods, tie backs, or tie reinforcement rods. These 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.
How a tie rod hole is formed.
Once the forms are 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).
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 spray a tar based coating. After a few years this coating will break down and water will begin to enter the holes. Over the years since pouring of foundations began, there have been varying attempts and methods to stop these leaks. Some work for a few years while others fail quickly. Repair contractors have applied a polyurethane caulk and cork method for a quick fix, but years later the leak returns. The leak returns because these methods do not utilize a sealing system that reacts or co-exists with water. Instead, they use methods or products to bond up the hole that will loosen later due to delamination of the product/surface area.
Revealing the tie rod hole from inside.
The inside of the wall is also coated with a trowel applied hydraulic cement to fill in the tie rod hole, then in some cases sprayed over with a white stucco type finish more commonly called structo-lite; a mixture of (Structo-lite and autoclaved Lime). 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. Removal of the trowel applied hydraulic cement reveals an open tie rod hole going all the way to the outside of the basement wall. A simple removal of the trowel applied hydraulic cement reveals a hole going through to the soil side where the exterior hydraulic cement has been applied in the same fashion.
Tie rod leaks can cause a lot of water damage in basements.
When tie rods holes begin to leak they can flood and destroy finished basements drywall and carpeting. Tie rod hole leaks have commonly been mistaken as drain tile failure. Due to the amount of water they can allow in 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 leaving a puddle on the floor with no traceable evidence of where it came from originally. The photograph below shows a case of one tie rod hole leaking, washing in soil from outside making it easy to trace. The amount of water resulting from this condition is commonly mistaken for drain tile failure.
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 outside soil.
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.
(This article comes from trxplug.com editor released)