Hurricane Ties/Clips

[Coder]

The AHJ (You) are the one who "approves" the connector. This could be nails if they will meet your uplift requirements.Clips and straps are not the only option check out Simpsons SDWC. 400 to 600 pund uplift depending on the wood species. They work great, contractors doing exposed wood projects really like them.

http://www.strongtie.com/products/connectors/SDWC.asp

Good point. I did not remember those screws from Simpson. I'll have to keep those in mind

 

[Francis Vineyard]

Don't remember who came out with the screw first; Timberlok or Simpson, but one of them answered back the first with a guide to achieve the correct critical drill angle. Found it; http://www.strongtie.com/ftp/fliers/F-SDWC12.pdf

Not sure about Mr. Inspector's question, but,Looking at the 2012 IRC it looks to me like "hurricane clips" are not required until you exceed a 200 lb. uplift force as detemined in Table R802.11. Table R802.11 determins the uplift force by Exposure Category, Roof Pitch and Roof Span. Looks like it is not a cookie cutter answer and in Category B, unless you go to 24" o.c. with your rafters or trusses and have a pretty good roof span, you are allowed to go with the toe nailing (fastener schedule) in Table R602.3(1)

I haven't adopted the 2012 code yet but we are reviewing it for adoptioned at the 1st of the year.

If anyone has already adopted the 2012 IRC an read this differently, I woud appreciate being corrected before I start enforcing this section.

Thanks

Yes it appears the 2012 removed the across the board mandate for across the board and added tables to help calculate when and the amount of uplift force required of the connection.

May the experts feel free to correct and elaborate.

Francis

 

[DRP]

Alright guy's, I have beaten myself up with this one but I think I have it figured out. According to the 2009 IRC section 802.10.5 Truss to wall connection; Trusses shallbe connected to wall plates by the use of approved connectorshaving a resistance to uplift of not less than 175 pounds and shall be installed in accordance with the manufacturer's specifications.(period) Therefore, I am concluding that clips/straps with 175 lbs of uplift resistance are required at each truss as a connector no matter what and a toenail(fastener)is not a connector.

A nail is a dowel type connector, there is an adjustment factor for toenail configuration. The awc.org connections calc gives the same output as the tables in the NDS for typical generic connectors... nails, screws, lags, smooth dowels, etc. Manufacturers provide tables for proprietary connectors such as the Simpson line. Do not be fooled into thinking a proprietary connector is required "no matter what". We were using lag screws in exposed beamwork long before the Simpson and Fastenals came on the scene, the new ones are certainly easier to use as are most proprietary connectors. They are not the only way though. Secondly, you might need more than 175 lbs of resistance, that was a minimum.

 

[GBrackins]

Secondly, you might need more than 175 lbs of resistance, that was a minimum.

so true Don. it's not uncommon in my area to have over 500 lbs uplift at the truss-to-wall connection. of course I'm in a 110 mph wind zone.

 

[brudgers]

so true Don. it's not uncommon in my area to have over 500 lbs uplift at the truss-to-wall connection. of course I'm in a 110 mph wind zone.

A 500 lb uplift connection can still be toenailed using NDS. Clips aren't magic.

 

[Coder]

A nail is a dowel type connector, there is an adjustment factor for toenail configuration. The awc.org connections calc gives the same output as the tables in the NDS for typical generic connectors... nails, screws, lags, smooth dowels, etc. Manufacturers provide tables for proprietary connectors such as the Simpson line. Do not be fooled into thinking a proprietary connector is required "no matter what". We were using lag screws in exposed beamwork long before the Simpson and Fastenals came on the scene, the new ones are certainly easier to use as are most proprietary connectors. They are not the only way though. Secondly, you might need more than 175 lbs of resistance, that was a minimum.

I am pretty sure that the contractor is going to use something that has the uplift resistance already defined by the manufacturer. Much easier to go buy a box of hurricane ties and install them/ get me off his back and be done with it. Otherwise, he can provide documentation that 2 16D toenails provides the min uplift requirements. Is there such info available at awc.org? Thanks

 

[DRP]

No doubt about it, "engineered" building components have better backup behind them than traditional methods, kind of funny when you think about it. I do use hurricane clips here in a typical dimensional lumber or truss roof, just pointing out that it is not the only way. The code lanuage in the structural chapters reads something like "or according to AF&PA's NDS". This calculator uses the formulas from the NDS.

http://www.awc.org/calculators/connections/ccstyle.asp

Continuing with the engineered products superior support, truss drawings will give the max reactions the connections need to resist. But again not the only way.

 

[brudgers]

I am pretty sure that the contractor is going to use something that has the uplift resistance already defined by the manufacturer. Much easier to go buy a box of hurricane ties and install them/ get me off his back and be done with it. Otherwise, he can provide documentation that 2 16D toenails provides the min uplift requirements. Is there such info available at awc.org? Thanks

When someone is using hurricane clips, do you check to see if they are using 10d x 1.5" when required?

 

[jar546]

When someone is using hurricane clips, do you check to see if they are using 10d x 1.5" when required?

We ask and want to see the box, but often we don't have to because it is obvious that they used roofing nails which is a common occurrence for some reason.

 

[brudgers]

The old timers told me that when Florida first started requiring trusses to be strapped, plumbing hangers were often used.

 

[Keystone]

To pick up on brudgers comment, when I was in the field we cut the metal lumber banding and used that as sole and top plate protection with roofing nails to hold in place, BOCA/CABO days.

 

[jar546]

Testing 123

Sent from my iPad using Tapatalk HD

 

[DRP]

JAR, were you testing to see if keystone knew his mike was on?

We liked the heavy banding that engineered items came strapped in.

 

[jar546]

No, we had an issue with the forum tonight. The anti spam program I installed got carried away and no one could post for a few hours. It is fixed now.

 

[Coder]

No, we had an issue with the forum tonight. The anti spam program I installed got carried away and no one could post for a few hours. It is fixed now.

Thanks for looking into that. Phew now I can relax. You too sir.

 

[peach]

An approved connection can be nails. IRC does put everything in 90 mph (with special wind zones), we need to be looking for something. Hurricane clips are great since they are engineered for this purpose - you still need to make sure they are installed correctly. Truss plans always give you the uplift (code still requires the connection to withstand 175 pounds of uplift even if the truss shops show 90). Rafters need to be calculated and that should be done at plan review.