Sleeves, Penetrations, and Embedments

On every build, there are a number of items that must be coordinated to either go through or into the ICF and concrete prior to concrete placement. This becomes an especially important planning exercise that requires coordination with other trades to get the size and exact location in the wall.

Failure to install these penetrations through the walls will result in a costly exercise in cutting holes through the solid wall. There is a long list of important utilities, services, and structural attachments that need to be addressed to be either in or through the ICF block prior to concrete placement, such as main electrical service, water service, sump pump lines, dryer or cooking vents, beam plates, roof and floor connectors, etc.

The main criteria to understand is that the ICF concrete and reinforcement has been designed to meet the load bearing requirements for the walls, floors, and roof plus lateral loads from the backfill and wind. The walls are structural elements, which means you cannot run any service lines vertically in the wall cavity. Any penetrations through the ICF block and the concrete must be installed horizontally, maintaining the structural integrity of the wall assembly and not interfering with the rebar placement.

Forgetting these elements means having to bore/drill or cut the concrete and possibly rebar after the concrete in the walls has been placed. This becomes a costly and labor-intensive issue that may compromise the structural ability of the wall. Every contractor that has experienced this has thrown their hands up in the air said “#&*#…,” understanding that this should have been installed before and figuring out who should pay for the extra work!

Photos courtesy of BuildBlock

Sleeves through the wall are easy to install as the ICF blocks are being assembled or before concrete placement. Once the exact location is known as well as the size of the penetration, mark out the diameter of the sleeve and what it is for on the face of the ICF. Minimize cutting the hole for the sleeve and locate the hole away from any ICF webs or vertical rebar. Some sleeves may be as large as 4 inches in diameter, while others could be much smaller for wiring (all wiring passing through an ICF wall should be in conduit).

A sleeve is typically PVC, metal conduit, or sheet metal, which will remain in place and is large enough in diameter to accommodate the pipe, duct, or wiring to fit inside and through the wall. The sleeve length would be the exact width of the ICF block. The sleeve itself must be strong enough to withstand the concrete drop height during placement. For larger sleeves, temporary wood support inside the sleeve is recommended. During concrete placement, let the concrete flow around the sleeve and avoid directly dropping concrete on the sleeve. Always watch during placement that the sleeve is not displaced or damaged.

In the design of the project, main electrical and plumbing stacks, which are generally 3 inches or more, must be designed to be located on the interior side of the wall or in an interior framed wall, not placed in the concrete cavity. On the interior, electrical wiring, conduit, plus plumbing lines 2 inches or less are cut into the EPS foam after the concrete is set. This is a simple process using a hot-knife, router, or electric chainsaw to route out a 2-inch deep cavity in the 2 5/8-inch EPS, cut through the furring strips where necessary. This provides a cavity in the EPS to insert the wiring or plumbing, which meets code and makes the installation fast and quite easy.

After concrete placement and the service is inserted into the sleeve, the area around the sleeve and around the utility must be sealed to be air and watertight. If the sleeve is below grade, a flexible peel-and-stick membrane is applied around the sleeve. Ensure the edges are sealed with a compatible waterproofing compound. The space on the interior of the sleeve around the utility must be filled with an expansive spray foam insulation and made airtight with an ICF compatible waterproof sealant or caulking. Above-grade penetrations must be addressed in the same manner to be sealed against water and air intrusion.

This task of sealing the penetrations is something that the ICF contractor should handle or inspect to ensure the work is done properly, preventing air or moisture intrusion through the ICF wall assembly.

Similarly, structure embedments or anchors, such as bolts, floor ledger connectors, hurricane straps, and beam attachment plates, must all be coordinated and ready to set in the wall, prior to or during the concrete placement. If necessary for beams, a void form is used to create a beam pocket. Once the concrete has been placed, the void form is removed, providing a structural seat for either wood or steel. Wood beams should not bear directly on the concrete. Provide either a metal or pressure-treated bearing plate or poly protection under the beam to prevent any moisture transfer.

If the ICF contractor is not doing the floor or roof systems, then the ICF contractor must coordinate with the carpentry or steel contractor for the type and exact location of any embedments and have that equipment on the job site prior to concrete placement.

Penetrations must be installed correctly and sealed adequately to prevent air and moisture intrusion. Structural embedments are coordinated and installed as specified. As the ICF contractor, this type of coordination and diligence up-front will save time and money and contribute to a successful project, enabling all the true benefits of building with ICFs.