Lag Bolt Load Info
Lag Bolt Load Info
(OP)
I'm trying to establish a safe lad bolt (1/2 inch diameter) and (3/8 inch diameter) in a SPF ledger + SPF band joist.
Virginia Tech study is based on Southern Pine ledger + SPF band joist. They say testing shows a 30 OC spacing ( 6 ft joists) with 1/2 inch bolts (using 0.39 in throat).
S Pine has a compressive stress (perp to grain) @ 565 psi. At 30 in OC the deck load would be approx. 375#/ bolt? Would this not cause cracking in the ledger (therefore failure)? They say this 30 in OC is based on a SF = 3.0
Can someone suggest an equation, to come close to this test value for 1/2 inch dia bolts, then for 3/8 inch bolts?
I want to establish a safe load for a SPF ledger + SPF band joist (@ SG = 0.42 - comp perp grain @ 425 psi).
Appreciate your help.
Virginia Tech study is based on Southern Pine ledger + SPF band joist. They say testing shows a 30 OC spacing ( 6 ft joists) with 1/2 inch bolts (using 0.39 in throat).
S Pine has a compressive stress (perp to grain) @ 565 psi. At 30 in OC the deck load would be approx. 375#/ bolt? Would this not cause cracking in the ledger (therefore failure)? They say this 30 in OC is based on a SF = 3.0
Can someone suggest an equation, to come close to this test value for 1/2 inch dia bolts, then for 3/8 inch bolts?
I want to establish a safe load for a SPF ledger + SPF band joist (@ SG = 0.42 - comp perp grain @ 425 psi).
Appreciate your help.





RE: Lag Bolt Load Info
The load on the deck was (40 psf LL + 10 psf DL).
Why is this equation not adequate? It gives a load much less than in tables based on V techs data?
I am grateful for your help here, thanks.
RE: Lag Bolt Load Info
http://www.fpl.fs.fed.us/products/publications/sev...
RE: Lag Bolt Load Info
Yes, that was the yield equation I used to get the 184 pounds / bolt.
Much lower and very conservative compared to V tech data.
Need to find an equation or method that estimates the bolt load near to V tech test data,
Any suggestions, or links?
RE: Lag Bolt Load Info
RE: Lag Bolt Load Info
I was hoping someone on line might be able to explain this.
I did not think it was too complicated to obtain a reasonable solution in this form.
I would be grateful for your help.
Thank you
RE: Lag Bolt Load Info
RE: Lag Bolt Load Info
Try the American Wood Council web site's lag bolt calculator:
http://www.awc.org/calculators/connections/ccstyle...
RE: Lag Bolt Load Info
Here's an example from AWC:
http://www.awc.org/pdf/DA1-LagScrew.pdf
RE: Lag Bolt Load Info
Mike McCann, PE, SE (WA)