BuildBlock Prescriptive Engineering

BuildBlock provides a variety of engineering information for the United States & Canada to make building with BuildBlock ICF products simple and straightforward.

The BuildBlock Engineering Manual extends prescriptive and safe room engineering for greater wall heights above and below grade as well as making it easier to design FEMA 361 compliant safe rooms. The BuildBlock ICF Products & Safe Room Engineering Manual increases the scope of prescriptive engineering for BuildBlock ICF products. This document is intended to be used in conjunction with the PCA 100 Prescriptive Design of Exterior Concrete Walls for One- and Two-Family Dwellings when determining reinforcement for residential walls and as a reference for commercial engineering.

  • Below grade wall include 12ft heights for all products and 14ft in certain applications.
  • Maximum above grade wall heights are engineered to 14ft for all products and 20ft in certain applications, reducing the need for site specific engineering.
  • Easy to read lintel design tables are based on opening sizes and provide clear reinforcement requirements.
  • FEMA 361 & ICC 500-2014 compliant prescriptive design for safe rooms with spans up to 22ft, wall lengths up to 44ft, and wall heights up to 20ft.
  • Rebar conversion tables to convert between single and double bar applications.
  • The IRC, the PCA 100, the Prescriptive Method, and ACI-318 are recommended companions to this engineering manual.

BuildBlock Engineering Manuals

BuildBlock Flat Wall & Safe Room Engineering Manual
BuildBlock Pool Engineering Manual
BuildDeck Design, Engineering & Installation Manual
3 documents

US Department of Housing and Urban Development
Prescriptive Method for Insulating Concrete Forms in Residential Construction, Second Edition
(January 2002, 214 p.)

U.S. HUD Prescriptive Method for Insulating Concrete Forms in Residential Construction, Second Edition

This document has been replaced by the BuildBlock Flat Wall Engineering Manual: Above & Below Grade ICF Walls, Rebar Reinforcement, and Safe Room Design. But the engineering is still valid for use and reference.

Insulating Concrete Forms (ICFs) represent a category of building product that is receiving greater attention among builders. ICFs are hollow blocks, planks, or panels that can be constructed of rigid foam plastic insulation, a composite of cement and foam insulation, a composite of cement and wood chips, or other suitable insulation material that has the ability to act as forms for cast-in-place concrete walls. The forms typically remain in place after the concrete has cured, providing well-insulated construction. ICFs continue to gain popularity because they are competitive with light-frame construction and offer a strong, durable, and energy-efficient wall system for housing.

The first edition of the Prescriptive Method for Insulating Concrete Forms in Residential Construction represented the outcome of an initial effort to fulfill the need for prescriptive construction requirements and to improve the overall affordability of homes constructed with insulating concrete forms. The first edition also served as the source document for building code provisions in the International Residential Code (IRC).

The second edition expands on the first edition by adding provisions for Seismic Design Categories C and D (Seismic Zones 3 and 4). Wall construction requirements utilizing Grade 60 reinforcing steel and concrete mixes with selected compressive strengths are included. In addition, tables throughout the document have been simplified as a result of additional evaluation and user input.

Prescriptive Method for Insulating Concrete Forms In Residential

The Prescriptive Engineering Method

For the code-approved installation method of ICFs and engineering tables, download this document for free from the HUD website at: or below.

Prescriptive Method for ICF 2nd Edition
Prescriptive Method for ICF 2nd Edition Appendix
2 documents

BuildBlock Engineering Tables