Click on the thumbnails below to see the parts of a bearing wall, or a floor cross-section.
Framing is one of the most exciting phases of the construction process. During the framing phase you will watch the house take shape. Most people get very excited when the framing is done, thinking that the house is almost built. In reality, the house is only about one-third complete.
The framing must be accurate. If the framing is poor quality, the drywall won't be flat, the floors will squeak, and doors will not close correctly. The job of the general contractor is to make sure the framers follow the plans and the building code.
In traditional platform framing a platform or floor is built on the foundation. The structure is bolted to the foundation with anchor bolts and hold down straps. Walls are placed on top of the floor joists, followed by the roof trusses Traditionally, the floor joists are made of 2x8 - 2x12 boards. However, today the best choice for floor trusses are composite "I" beam joists. They are environmentally friendly using up to 60 percent less wood to make than a solid wood joist and are straighter, stronger and lighter than traditional floor joists.
The subfloor made of 3/4 inch OSB or plywood is attached to the joists with nails and glue to prevent squeaks later on. Using screws instead of nails is highly recommended.. The walls are built of 2x4 studs (2x6 exterior wall are an option). Studs, top and bottom plates, headers trimmers and cripples form the walls (click on graphic above). The interior of the walls will be covered with drywall and the exterior walls with 7/16 inch sheathing (OSB or plywood).
The roof is formed with pre-manufactured trusses or stick-built on-site. Trusses are built off-site. They are delivered to the site and hoisted onto the walls using a crane. Trusses are strong, install quickly, and can be built to almost any roof design. They are engineered to sustain a live load, dead load, wind resistance and snow load (see construction dictionary).
The city inspector will usually request the truss engineering calculation during the framing inspection.
Stick built roofs allow for a little more design flexibility and better use of attic space. Carpenters cut and assemble boards on-site. Material for a stick-built roof is cheaper than trusses, however labor costs a make stick-built roof more expensive.
The time it takes to frame your house will depend on the size, complexity, and weather conditions. Ensure that your contract has a start date and a completion date. If the job is delayed penalties should accrue against the framing contractor. Never pay the contractor until the work is finished! Retain 10 percent of the total bid until after the framing inspection.
The contract price for framing should include labor, fasteners (nails, hold downs etc.) crane rental (to set trusses). Whether the price includes materials depends on the framers and yourself. Often, it is a good idea to purchase the lumber, trusses, exterior doors, and windows yourself. If you provide the materials you won't have to worry about liens from suppliers.
If necessary, hire a carpenter to check the work of the framers. He will be able to spot potential problems that you might miss.
The city will require a framing inspection. The inspector will check that the building codes are followed. Generally, they will find some corrections. Don't count on the city framing inspector checking the quality of work! The framing itself took a few weeks, and the building inspector will probably spend less than one hour on the job. He will look for code issues, not quality issues. Fire blocking is an important issue that he will inspect. Talk with your framing contractor about fire blocking.
Safety and security are two major concerns during the framing process. Keep the site organized and free of hazards. Pick-up loose nails and scraps of wood. If necessary post warning signs and hazard tape to keep people off the site. Lumber has a way of disappearing from building sites. Keep inventory of the materials on site and don't deliver excess material.
Labor Costs- Most framers will price the framing job by the square foot, and difficulty of the design. Steep roofs cost more, as do vaulted ceilings and cut-up designs. Cut-up design are designs that are overly complicated. Stick framed roofs also cost more.
Materials- Take a set of your plans to three lumber yards. Generally they will have estimators that will make a materials list. The list will include the individual quantities and costs. The lumber industry is very competitive so often the service is free. Check on the delivery charges, how fast orders can be filled, and if telephone orders can be made. Ideally, lumber should be delivered the day before the framers start.