Tie Rod Holes Explained

The following description supports the condition of leaking tie rod holes left from foundation forming systems that use 5/8″ reinforcement rods. After constructing the foundation wall, these rods are removed with the wall forming system, leaving holes in the poured concrete wall. Other forming systems that use snap-ties do not apply to this description or product. Snap-Ties are explained at the end of this page.

Poured concrete foundation walls begin with the construction of forms in which to pour the concrete. 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 and about 5 feet high from the basement floor across the entire basement. A second row is aligned vertically underneath and about one foot from the base of the floor. Basements higher than eight feet sometimes will have three rows aligned vertically.

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 concrete is poured, the forms are left a few days for curing. When that is accomplished, the tie-rods are removed allowing the shuttering to be dismantled. When this 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 in diameter. In this forming system, the rods (are not) left in the wall. The only time supporting ties are left in the wall is when (snap-ties) are used.

Examples of tie rods

© 2014, Mr. Sponge Waterproofing, Inc.

After the forms are removed some contractors will apply cement on the outside of the tie-rod holes and spray a tar based coating on the outside, (see below). 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. Many waterproofing 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” with water, rather they use methods or products to bond up the hole that will loosen later due to water.

Tar coating on the outside of a poured cement foundation.

© 2014, Mr. Sponge Waterproofing, Inc.

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 Lime). The tie-rods holes in this case 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, (see below). Thus, the condition thousands of poured basements have.

Picture 140

© 2014, Mr. Sponge Waterproofing, Inc.

When tie-rods holes begin to leak they can flood and destroy finished basements drywall and carpeting. Tie-rod hole leaks have been mistaken as drain tile failure. Due to the amount of water they can turn 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 picture below shows a case of one tie-rod hole leaking, washing in soil from outside and the amount of water resulting from this condition.


© 2014, Mr. Sponge Waterproofing, Inc.

Some tie rod holes become an entrance for ants as they use the hole for a nest. The photo below shows a tie rod hole exposed behind a 2 x 4 stud and as soon as the front cap was removed, the result is seen here.

Picture 14

© 2014, Mr. Sponge Waterproofing, Inc.

Another example to show how much water can come in your basement from tie rod hole leaks. Here, the customer used a rope to wick the water into the storage containers.

Picture 8

© 2014, Mr. Sponge Waterproofing, Inc.

Important note for Homeowners: If you are planning to finish your basement and it has tie rod holes as explained in this website, then you should consider repairing all of them. Leaving the holes unsealed will eventually cause future problems behind the drywall or paneling. Below in a photo showing drywall removal to repair leaking tie rod holes left unsealed when the basement was finished.


© 2014, Mr. Sponge Waterproofing, Inc.

When Not To Use: The TRX® Compressed Swell Plug is not designed to be used when the tie rod hole has a wall crack located through the hole, nor is it designed to be used when the tie rod hole is located within a honeycomb area of concrete; (where excessive aggregate has cured in a given area causing seepage through the aggregate). If the tie-rod hole has been repaired before then it must be drilled out clean with a 5/8″ masonry bit prior to application.
Consumer Note: Some forming contractors use metal forming systems that utilize a flat metal bar instead of a 5/8 rod. This product supports the forms that use the 5/8 tie rod that leaves holes in the poured concrete foundation after construction. This product will not be used for the thin flat metal bars, (snap-ties), that have the ends broken off and still in the wall. See Photo below for Snap-tie identification. Snap-ties also can be in varying forms such as the one below that looks like a flat bar of steel. Others may be shaped like a small square of metal measuring approximately 1/4″ x 1/4″.

Picture 7

© 2014, Mr. Sponge Waterproofing, Inc.

Notice: 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.