Messages and Online Forum Q&A

Re: Short beam

From: info@builderswebsource.com
Category: Structural
Remote Name: 63.198.181.43
Date: 27 Apr 2001
Time: 07:40 PM

Comments

We would need to know the dimensions of the roof in order to compute the tributary dead load imparted on the new 6' header. In addition, the snow load design parameters for Western Canada vary greatly. For example, in West Vancouver, the snow load can be up to 65 psf at 320-380m elevation. In Whistler, it can be 167 psf. And in Windy Craggy, it can be up to 272 psf. These figures are according to British Columbia Snow Load Tables.

However, assuming your roof is of "ordinary size" and the beam size is 6 feet and the roof tributary length is no more than 15', a 6x12 DF #1 header is sufficient for a total live + dead load of 100 psf. At 200 psf (such as in Whistler), a 6x14 DF #1 or 6x16 DF #2 would be required. At 300 psf (such as in the most snow-bound parts of Western Canada, the beam would need to be at least 6x16. Alternatively, you could use a short section of glulam such as 5-1/8" x 13-1/2". We would also recommend using one 2x6 king on each side of the header as well as a 4x6 post supporting the header secured with steel column-beam saddles. In fact, the king studs in contact with the Trombe wall should be 2x6 pressure-treated and anchored into the wall with lag bolts. This will provide a solid surface to which you can secure the jack studs and header. Use additional metal tie straps to secure the header to the king and jack studs as well as the top plates.

If you're looking to optimize the size of the beam, then you'll need more precise load information, coupled with the BeamChek software available here. Please note, all information provided by Builders Websource is for general reference only. You must consult a licensed structural engineer to assess your particular conditions and compute a design optimized for your project.

Builders Websource

Article Tools

Builders Websource® is a corporate member of ASTM International—a non-profit engineering body dedicated in part to the standardization of building materials specifications, products, systems, and test methods for improved health, safety, and reliability of residential and commercial structures.

Copyright © 1999 - 2008 Builders Websource®, an InBuild™ company. All rights reserved.