No cold joints are allowed in foundation walls. The foundation will retain backfill and must be constructed to full height. ICF Foundation – A below-grade foundation or basement wall could be six, seven, or more courses high, with an above-grade wood frame structure bearing on top of the ICF wall. The top of the wall is connected, either with anchor bolts or metal straps cast into the concrete. The wall is laterally supported at the bottom by footing dowels and by the floor system bearing on the ICF concrete core at the top. Build this wall to full height and place concrete monolithically to the full height. ICF Crawl Space – A crawl space is typically a two- to three-course short wall assembly, which may have minimum backfill pressure. The backfill may be slightly uneven on the wall being laterally supported at the top by a slab or floor assembly. These small walls are typically poured as continuous monolithic walls from bottom to top. ICF Frost Wall – Frost walls are a few courses of ICF block in the ground with backfill on both sides. This is a basic overview of the “‘how to” for each: In all applications, and in all ICF core sizes, the bottom of the ICF wall is connected and laterally supported at the footing or slab with reinforcement dowels. The type and size of ICF structures relates to the sequencing of the installation. In the review of the installation sequencing, it is very important to understand the technical principles and applications of lateral supports and cold joints. Similar principles apply, but it is recommended that an engineer design the detailing and location for these. Note that in some larger projects, due to time allocation versus volume of concrete to be placed, a vertical cold joint may be required. Cold joints are commonly installed in above-grade walls between the concrete placement per floor level. Cold joints create a rough horizontal seam in the wall that must be installed with rebar dowels to structurally tie the two layers of the concrete wall together through the joint. Cold joints are NOT allowed in below-grade foundation walls that will be retaining backfill. Cold joints are allowed in the construction of above-grade concrete walls but must be designed with overlapping rebar dowels and located at an appropriate spot in the wall assembly. This creates a cold joint or a physical seam in the wall. Walls not only support the vertical or point loads of the building but are subjected to a continuous live load, laterally/horizontally, which may cause walls to move or shear from soil pressure, wind pressure, or earthquakes.Ĭold Joints – Cold joints are horizontal when the placement of concrete is interrupted or delayed, allowing the first level of concrete to set (harden) before the next level is placed. Lateral Support – These walls are basically designed to be laterally supported at the top and bottom, meaning that the walls are physically connected to a footing, slab, floor, or roof system, preventing and securing the walls from moving inward or outwards from any lateral pressure. For ICF applications, there are two major technical/structural terms that every installer must be cognizant of and follow - lateral support and cold joint. Naturally, the build sequence applies to the size of the building and some major structural principles, but generally, ICF construction sequencing is similar to conventional construction: footings, foundation walls, main floor and main floor exterior walls, second floor and exterior walls, roof. For a new ICF installer there is considerable information from the ICF manufacturers about how to lay the blocks, but one of the main questions being asked on social media is about the construction sequencing or phasing - how many courses to install and when to place concrete.
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