QA

Question: How To Frame A Floor On Posts

What are the two common footing problems with Piers?

Sagging, sloping, and buckling floors are common issues with pier and beam foundations. The type of repair for pier and beam foundations depends on what exactly the problem is. Repairing a pier and beam foundation may require replacing rotten wood or installing new beams and joists or even re-shimming the foundation.

Where is the rim joist located?

Rim joists are located at the top of your basement walls. They usually look like wooden squares going around the perimeter of your basement. The main purpose of a rim joist is to support the weight of the floor resting on the joists.

What do floor joists sit on?

At the foundation level, floor joists rest directly on a sill that is treated with preservative so that contact with the foundation will not promote termites or rot. Their exact construction and connection with the wall studs depend on the method of framing that is utilized.

What size lumber is used for floor joists?

There are several different sizes and types of floor joists. The most common sizes are 2×8, 2×10, and 2×12.

How do you nail floor joists to sill plate?

Start an 8-penny nail as a toenail, 1 inch from the end of the joist and 1 inch from the bottom of the joist. Drive the toenail into the sill plate at a 45-degree angle, but do not drive it fully at this time or you will move the joist off of the layout mark.

Do you install subfloor before framing?

If you use a product like DriCore for the subfloor, they even explicitly recommend you frame on top of their subfloor product. They do, however, recommend you screw the framing through the subfloor into the concrete with something like 3″ Tapcons spaced every 4 ft through the bottom sill of the framing.

Do I need a subfloor over concrete?

If you don’t plan to use the space, there is no need for a subfloor or floor covering. Concrete or tile-over-concrete are acceptable floors for uninhabited basements. But to install any kind of floor covering—engineered wood, laminate, carpeting—basement subflooring is highly required.

How do you install floor joists on a concrete slab?

Install it flat on the slab surface, with the outside edge aligned against the side wall or the edge of the floor line. Secure each length to the slab with concrete nails spaced approximately 32 inches apart and 8 to 12 inches from each end. These will be the end “sill plates” that support the ends of the floor joists.

What raised foundation?

A raised foundation is the physical structure of the footings and walls or piers that support the home to create the crawl space.

Is it cheaper to build on a slab or piers?

Concrete slabs can be constructed very easily and are cheaper than pier and beam foundations. However, you should know that repairing and maintaining a concrete slab can be more expensive in the long run than taking care of a pier and beam foundation.

How far apart should foundation piers be?

While 8 to 10 feet apart is a sufficient distance for foundation piers to support most structures that would sit atop a post and pier foundation, if the building is particularly tall or made of heavier materials such as brick or metal, it’s not uncommon to place the foundation piers even closer together.

Is post and pier a permanent foundation?

Post and pier homes, manufactured homes, modular homes, and mobile homes are just a few homes supported by piers. Furthermore, piers can be made from stacking concrete blocks. So, often you will find piers considered a permanent foundation.

What is the purpose of rim joist?

In the framing of a deck or floor system, a rim joist is attached perpendicular to the joists, and provides lateral support for the ends of the joists while capping off the end of the floor or deck system.

Why is a rim joist necessary?

The main job of a rim joist, also called a band joist, is to provide lateral support for the joists, to prevent the joists from leaning under the weight of the load-bearing walls resting on them.

Is rim joist necessary?

Yes, if your framing a house or a deck you’ll need a rim joist. They create the edge of your floor framing and close off the open edges. For example, if your framing a 10×10 deck off the back of your house, you’ll probably be using 2×8 or 2×10 joists spaced 16 inches on center.

Does Sistering floor joists work?

Sistering joists means beefing them up with additional material. Doing so strengthens weak joists and can help straighten sagging joists. Framing lumber is the typical choice for sistering material, but engineered lumber products actually add more stiffness than dimensional lumber.

What is nailed to the top of the floor frame?

The subfloor, also known as rough flooring, is nailed to the top of the floor frame. It strengthens the entire floor unit and serves as a base for the finish floor. The walls of the building are laid out, framed, and raised into place on top of the subfloor. Panel products, such as plywood, are used for subflooring.

How long can floor joists be without support?

With 16” spacing, a floor joist can span up to 14′ as long as it is not cantilevered and terminates with support on either end. If the joists are 24” apart, then one 2×10 joist can span up to 11′ 5”. These lengths are for SYP lumber.

Are 2×6 OK for floor joists?

2 Answers. 2×6 joists at the span that you are talking about (16′ and 18′) are not strong enough to support a floor as a living space. With a span like that the timber size that you sister in would have to be at least 2×10’s.

Can 2×4 be used for floor joist?

It should be OK, but I’d go closer than 16″ OC. 2x4s are cheap. another option might be to put plywood below the joist as well as above. This would make the plywood the stressed member and the 2x4s would be acting more like the webbing of an I beam.

Do floor joists need cross bracing?

For a new home, you’ll want to install cross braces during the construction of the floor frame, to avoid the aforementioned floor problem in futures. Basically, cross-bracing your floor joists makes your wood frame floor system stiffer, consequently preventing twisting, deflection, squeaking, sagging, and bouncing.

Can you build your own floor trusses?

Do not build a floor truss without understanding how to build it to fit your specific needs. Floor trusses are custom built to meet specific construction needs. One of the most common support systems for floors in houses and commercial buildings is the open-web truss system.

What is the typical size of floor joists?

Typical Floor Joist Size In Residential Construction Floor joists range from 2×8 to 2×12. It is less common to see joists that are 2×6, even though they are included in joist span tables. Older homes are more likely to use 2×6 for joist framing.