The attic above my garage was modified poorly for attic storage. I’m looking to redo the Joists in order to properly store above my garage. The Current Joists are 21 feet long and are only 2x8s. Would 2x12s spaced 12″ apart with 3 or for blocks between joists be adequate? There is not currently any beam to support this load. I would be sheathing this space with 3/4″ plywood. I have no experience with home building or construction, just a DIY guy. I live in central California if that makes any difference. thank you all in advance.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Old masonry may look tough, but the wrong mortar can destroy it—here's how to choose the right mix for lasting repairs.
Featured Video
Highlights
Fine Homebuilding Magazine
Fine Home Building
Follow
-
Fine Homebuilding
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial Now -
GBA Prime
Get instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
- Home Group
- Antique Trader
- Arts & Crafts Homes
- Bank Note Reporter
- Cabin Life
- Cuisine at Home
- Fine Gardening
- Fine Woodworking
- Green Building Advisor
- Garden Gate
- Horticulture
- Keep Craft Alive
- Log Home Living
- Military Trader/Vehicles
- Numismatic News
- Numismaster
- Old Cars Weekly
- Old House Journal
- Period Homes
- Popular Woodworking
- Script
- ShopNotes
- Sports Collectors Digest
- Threads
- Timber Home Living
- Traditional Building
- Woodsmith
- World Coin News
- Writer's Digest
Replies
It’s not a straight forward answer unfortunately and you will need to refer to your local code authority, but for general guidelines follow table R502.3.1 of the IRC (can Google it) as this is the base line standard for building code. It will all depend upon your use, species of lumber, spacing and etc.
Whiplash it looks like you will need to support your joist at mid span from below with a built up/ engineered beam.
A good lumber yard should be able to have a joist manufacturer run the calculations for you.
Got it, I'll see if I can find someone to inspect and advise me on where to run the beam. thank you all for the advice.