Lecture Notes: Building Structures - Platform Framing

Introduction

• Buildings can have various structural materials.
• Understanding materials and their assembly processes is crucial for evaluating projects.

Platform Framing Overview

• Most Popular Method: Used primarily in residential construction, adaptable for multi-level and single-story structures.
• Concept: Based on a "building block" concept — one block stacked on top of another.

Components of Platform Framing

Base/Platform

• Rim Joist: Forms the exterior envelope.
• Support System:
  • Girder Beam: Main supporting beam.
  • Intermediate Joists: Supported by the girder beam and perimeter foundation wall.
• Decking:
  • Made from 4x8 plywood sheets.
  • Thickness varies (1/2" to 3/4") depending on joist spacing (16" or 24" on center).

Support Walls

• Comprised of:
  • Bottom Plate and Top Plate: Define horizontal extents.
  • Studs: Fastened with nails, provide vertical support.
• Load-bearing Walls:
  • Horizontal bridging between studs for additional support.
  • Walls are framed, lifted into place, and temporarily supported.

Wall Assembly

• Walls are built in segments to manage weight and ease of installation.
• Second Top Plate: Overlaps segments to tie them together.

Multi-Story Structures

• Process is repeated for each level until reaching the roof.
• Roof framing will be covered later.

Sheathing

• Walls can be sheathed while framing or after placement.
• Pros and cons exist for each method.

Summary

• The lecture covered the basic setup of platform framing—base, support walls, and the building block concept.
• Discussed the adaptability of this method in various building types.

Note: Consider the advantages and disadvantages of sheathing methods independently.