Understanding Roof Truss Reaction Bearing Size

The two lines denotes the direction of the plate.

Understanding roof truss reaction bearing size.

We know the basics of equilibrium of bodies. Just remember the acronym. In some cases the size or shape of wood trusses is such that some field assembly is required. Per 2018 ibc international building code sec.

Learn truss analysis methods with examples. O shear plate required on all notched bearing for ledger details with reactions over 500lbs x dol as shown below program applies shear plate automatically if end vertical analyzed as top chord. The minimum bearing size is 1 1 2 inches. Truss a pre built component that functions as a structural support member.

4 7 12 would be the dimension 4 7 12 16 or 4 7 3 4. The answer is a convention of the truss producing industry. The examples of these are the sides of. The first thing to consider with bearing sizes is the minimum required by the building codes.

Table 9 1 in span tables for joists and rafters figure 5 gives a required compression value of 237 psi for a span of 16 feet and bearing length of 1 5 inches. Roof floor truss manual 7 31 08 10 43 am page 11. Mitek engineering software calculates minimum bearing size based on default bearing material and compares it with bearing size input by the truss designer. 2308 7 3 1 when a ceiling joist is supported directly by the top wall plate wood the minimum bearing size required is a 1 1 2 inches.

Member above a top chord bearing must be labeled as a block and the vertical next to it must be a top chord. We will now discuss the trusses that are used in making stable load bearing structures. When the 4x4 block length is extended this is referred to as mid chord bearing. This stands for f eet i nches s ixteenths.

The truss chord member bearing on the support. Cojinetes de truss ubicaciones de cojinetes de soporte anchos requeridos de los cojinetes nota. So for example a dimension string that reads. Analysis of truss by the methods of joints and by the methods of section is explained in the article.

Truss to truss connection details i e hangers maximum reaction force and direction b. Intermediate bearing floor truss supported by steel or wood beam special engineering required. Bearing supporting the truss. 12 truss height the height of the truss from the top of the bearing to the top of the top chord trusses with multiple levels of top chord will have multiple truss height dimensions feet inches sixteenths 13 plate size orientation and type plate size in inches.

A truss employs one or more triangles in its construction. Minimum heel height with leg down 12 requires two joints. The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value. At mitek it is our opinion that this includes wood trusses.