Floor Joists Cont.

4/13/10

3rd type of Floor joist: Engineered

• Engineered, human made, Glue Lams, Wood I beams == All mean about the same thing.

• These are terms that refer to wood I beams that have been engineered to carry a structural load.

• Pros: cheap, light, easy to place electrical and mechanicals later in the build.

• Cons: no reputation, has only bee around for less than 15 years.

Engineered Joists Cont.• They are greener: If designed for your house.– Let me explain: You can buy these type joists from a

big box store and cut to fit the result still works but not green.

– If working with a aritect or lumber company: you build greener only using what you need.

– Hayward's system– Different System Engineered floor systems– How to build a post WWII house– Leed Home Builders– Open joists

How to connect the joists to the girder.

• About 3 standard ways are most common– Setting the joist right on top of the girder– Using a ledger on a girder• Not to common• Lots of work

– Using a Joist Hanger

Joist Hangers

• About 15-20 years ago more and more constructions began using engineered support systems to connect parts of a house that where traditionally just nailed or a fixture was constructed. Now metal products that have been engineered are available to use. The joist hanger is one great example of this.

Bridging

• Bridging is installed in rows between floor joists at intervals not exceeding 8 feet.

• Purpose is to distribute concentrated load on the floor over a wider area.

• Bridging also prevents the side to side movement of a joist.

• Bridging can be wood or metal

Solid wood bridging

• Solid wood bridging is typically the same size as the joists and is installed in an offset fashion to permit end nailing.

Wood cross Bridging

• Should be at least 1”x3” nominal lumber

• It is placed in double rows that cross each other.

Framing an opening in a floor system

Insulating floor joists and Joist Pockets

• New Green Way• Another view• Old fashion Fiberglass

Assignment• Thinking about your foundation that you have

already drawn out. Using a piece of white paper draw out the perimeter of your foundation and lay out where the girder would be and where each floor joist would be placed do not forget stairway opening or other important parts of the floor joist system

• On the back side of the paper in at least 2 paragraphs explain your design and also what type of girder and floor joists you plan on using, and explain why.