Part2_floor_framing

Construction Technology
include component="page" page="toolbar_tcj2O" editable="1" Housing Unit: Part 1 | Part 2 | Part 3 | Part 4
 * HOUSING UNIT (TCJ2O)**
 * Part 2: FLOOR FRAMING**
 * Framing** - there are three main types of framing used in Ontario, they are Balloon, Post and Beam, and Platform. The most common being Platform because of it's saving of time, ease of construction and safety aspects. After the sill plate and beams have been installed the framing may commence. First a joist is toe nailed to the sill plate all the way around the perimeter of the building. This joist is known as a "Header Joist" on the edge of which all joist and floor openings may be laid out. All floor joists must be placed with the crown up (this means edge curve up), as over time and with any furnishings as a load the joist will straighten rather then curve more. All joists are placed at 12", 16", or 24" **O.C.** This meaning “on center” or from the center of one joist to the center of the next joist. The reason for using 12, 16, or 24 inch centers is because they will all divide evenly into 4 and 8 feet. This is the standard size of the flooring plywood to be installed on top of the joists.

The most important step in building a floor is to double check your outside dimensions with your plans and also check for squareness. This can be done using a long tape measure and the cross corner method. When you measure the two cross corners of any square or rectangle they will always be equal if your floor is square. **Check your models using this method.**

The most common material used today for floor joists is spruce. The size used could be anywhere from a 2 x 6, 8, 10, or 12. The size is determined in the Building Code. Charts are given with the span and load put on the joist determining its size species. Today you are also given the choice of many new products which will span further or use recycled materials.

Prior to installing the flooring "Bridging" is placed to spread the load put on one joist over a larger area. Three types are cross, solid and ribbon.

We have two main types of flooring - plywood and aspenite. Aspenite is made from wood chips mixed with a glue and pressed into sheathing. Both plywood and aspenite are tongue and groove on the long edges. Two recent methods of installing the flooring are to glue as well as screw it in place both will lessen floor squeaking.

** Model House Instructions ** 1. ** Header /Rim Joist: ** (2) 1/4 " x 3/4" x 10", and (2) 1/4 " x 3/4" x 5- 1/2" pine 2. ** Joist: ** (9) 1/4 " x 3/4" x 5- 1/2" pine 3.  ** Sub-Floor: ** (1) 1/8” Masonite
 * Bill of Materials and Cutting Plan for Floor Joist & Sub-floor **

Begin by measuring the outside of the square created by the sill plate. Do this by measuring your diagonals It should be six by ten inches if built to plan. If not adjust your Header lengths.
 * Layout **

1. Layout the Header Joist at one inch intervals along each. This will represent your joist spacing remember in a full scale floor this would be either 12, 16, or 24 inch spacing. 2. Using the hot glue gun put a dab on the edge of the headers and a fix them to the sill plates. 3. Next put a dab on the end of each joist and place it between the two long header joists on your space markings. See diagram below.

4. Using 1/8" masonite, turn your model upside down and placing it in a corner next, trace the outline of the floor on the plywood. Cut the corner above the post in a wavy pattern this will show a cut away model and reveal the joists beneath the flooring.  Name:
 * FLOOR FRAMING **

The following questions deal with framing methods and materials. The answers may be found on page 165 "Intro. to Wood & Construction" **Do not write in this workbook.**

1) Give three advantages to "Platform Framing".

2) Two types of girders are...

3) The joist that holds all the regular joists in place is called what ?

4) Why are the floor joists spaced 400 mm (16 ") apart ?

5) The term "O.C." means, what ?

6) Where are floor joists doubled ?

7) Just as important is that the crown be placed _.

8) Three types of bridging are...

9) Plywood flooring is laid at right angles to the joists and the long edges are tongue and _ . ...click on the following link for the ANSWERS