6 Floors (upper Floor Of Timber) (1) 3a701n

Types of Upper Floors: Based on materials used for construction: Depending upon the materials used for construction and upon the arrangement of beams, girders etc. for ing the flooring upper floors are classified as: 1. R.C.C. Floors 2. Steel joist and stone or precast floors 3. Jack Arch floors (brick and Girder Cement Concrete Floor) 4. Filler Joists Floors 5. Precast Concrete Floors 6. Timber Floors

6.

Timber floors

• Found in earlier construction • Costly( Except at those locations where local timber is cheaply available) • Fire Poor resistance • Highly vulnerable to termite • Light in weight • Sound insulation Timber floors are basically of three types: A. Single Joist Timber Floors B. Double Joist Timber floors C. Framed or Triple Joist timber Floors

A.

• • • •

Single Joist Timber Floors

Simple type of timber floor Used for short span mainly for residential bldgs. Span up to 4 mt. For lighter load

Single Joist Timber Floors • The end of the joists are nailed, cogged or notched to the wall plates. • If the joists of adjacent room run in the same direction, they may be overlapped and nailed to each other. • Planking consists of wooden boards of 4 cm thick and 10 to 15 cm width, which are fixed to the bridging joists.

B.

Double Joist Floor

• Stronger Floors • Used for span between 3.5 to 7.5

Double joist floor • The bridging joist are ed on intermediate wooden known as binders • Loads of bridging joist are transferred to the binders and through them to the end walls • Because of intermediate s the bridging joist are of smaller sections • Joist are spaced at 30 cm centres

Double Joist Floor • • • •

Spacing of binders is kept at 2 to 3.5. Binders rest on stone or wooden templates. To reduce the depth of floors bridging joist are cogged to the binders. Ends of bridging girders are cut and t with help of fillers provided along the two sides of walls.

C.

Triple or framed joist floor

• Floor is suitable for spans greater then 7.5 mt. • Intermediate known as girders are provided for the binders

• Elements for flooring 1. 2. 3. 4.

Floorboards Bridging joist Binders Girders

Triple or framed joist floor

Triple or framed joist floor • Bridging joist s the floorboards • The binders are staggered and connected to girders to increase the rigidity of the floor to decrease the overall depth of floors • Sometimes girders are replaced by rolled steel joists

Comparison of all three Timber floors: Single Joist Timber Floor

Double Joist Timber Floor

Triple Joist Timber Floor

1

Simple type of timber floor

Stronger Floors

Very Strong Floor

2

Span up to 4 meters

Used for span between 3.5 to 7.5 meters

suitable for spans greater then 7.5 meters.

3

Element 1. Floorboards 2. Bridging joist

Elements 1. Floorboards 2. Bridging joist 3. Binders

Elements 1. Floorboards 2. Bridging joist 3. Binders 4. Girders