Saturday, August 26, 2006

Homebuilding and Framing Layout

When framing a house it helps to plan ahead for the layout of the framing members. When laying out, how you start will effect every phase of the project and dictate how you finish.

When starting construction on a new home the first layout would be for the floor joists. Before I even put a pencil to the sill plates to mark centers for the joists, I look at the roof plan. I let the type of roof the house has dictate what my layout is going to be.

The simplest layout would be for a home with a gable roof. If this is the case, then the layout of sixteen inch centers for the floor joists would simply start from the corner of the building. On the gable ends of the house, the layout would be started from the center of the building. The reason for this will be explained later.

When the roof is a hip roof, the layout for my first floor joist will be where the first common rafter winds up on the top plate. If the first common rafter is 11'9" to its center then that is where my layout for my joists will start. As with a gable roof, the layout on the end of the building will start from the middle. There is only one common rafter on the end of the house
and it will be in the center of the wall.

Now that you have laid out your floor joists, this will be the layout for all other framing components. After the plywood has been put on the floor joists, the layout for the exterior walls will follow the floor joist layout. Any interior bearing walls will also follow this layout.

After the walls have been framed and raised, the next phase of construction would be ceiling joists (if its a ranch style home) or second floor joists (if its a two story home). The layout for these would fall right on top of the studs in the walls. In the case of the ceiling joists, these would be nailed on the top plate to the side of the studs and the rafters would be nailed to the plate over the studs.

This method of framing is called "stacking". All framing members are stacked on top of each other to transfer the loads to the foundation and footings.

When framing the gable end of a roof, it is also laid out from the center. This puts a stud right under the ridge to give it support. All the walls below it are laid out from center also, so this support reaches all the way to the foundation wall.

Another reason for stacking the framing members is to create a chase or bay for mechanicals to go through. This makes it easier for the plumbers, electricians, and heating and AC trades to do their job. By using this method in a two story home, it creates a 14 1/2" space between framing members from the roof to the basement.

Stacking framing members in this method not only transfers the weight of the building to the foundation, but also makes for a structurely sound building. It also keeps the other trades cutting up of framing members to a minimum.

Plan ahead and keep it simple.

Mike Merisko (C) 2006

www.sawkerfs .com

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