Platform Floor Assembly
After the foundation is completed and the concrete or mortar has properly set up, assembly of the floor system can begin.
Framing of the floor and sills is usually done before the foundation is laid. This is because the floor frame helps the foundation withstand the pressure placed on it by the soil.
This section gives an overview of the procedures and method used for laying out and constructing a basic platform floor assembly.
When building any floor system, always coordinate your work with the work of people from other trades to ensure the framing is properly done to accommodate ductwork, piping, wiring, etc.
The construction of platform floor assembly is normally done in the sequence shown below:
Check the foundation for squareness.
Lay out and install the sills plates.
Build and/or install the girder and support.
Lay out the sills and girder for the floor joist.
Lay out the joist location for partitions and floor openings.
Cut and attach the joist header to the sills.
Install the joist.
Frame the opening in the floor.
Install the bridging.
Install the subflooring.
Installing Joists for Projection and Cantilevered Floors
Porches, decks, and other projections from a building present some special floor framing situation.
Projections overhang from the foundation wall and are suspended without any vertical support posts.
When constructing a projection, it makes a difference whether the joist runs parallel or perpendicular to the common joists. The projection must be framed with cantilevered joists.
This means that you have to double up common joists, and then tie the cantilevered joists into these double joists.