Truss Attachment

What is the best method for attaching roof trusses to the top plate; hurricane ties or structural screws such as TimberLock? Thanks

 

Check your local bldg code. I've always seen them toe nailed and then the hurricane ties were added .... to meet code.

 

That depends on where you are located an your local codes. Even within my state NC the code varies by location. Where I am 180 miles inland from the coast we are required to have hurricane straps in addition to nailing the truss to the top plate. 20 years ago they only required every other truss to have hurricane brackets but now they are needed on each one. And, don't forget to ask your inspectors what brackets specifically they will accept. Mine will accept several different types.

 

What the local building requires is a minimum. Nothing wrong with screwing and adding a hurricane bracket at each top plate and truss interface. Cost and labor is minimal.

 

The Timberlok screws are limited as to their holding power. All you have to do is download the specs and compare. That's readily available online. Hurricane anchors have superior shear strength... and even they differ depending on which type you use. All depends on the wind load the roof needs to be rated for.

 

Thanks to all who replied. I started this post because my building supplier recommended screwing in from below the top plates and into the truss as being better than using hurricane straps. The Canada building code only requires toe nailing (Sec. 9.23.3.4, Table 9.23.3.4). My own feeling is that further attachment with a structural screw from below the top plate is a good thing but to get maximum effectiveness the screw would need to be centered in the top chord which may not always happen. For this reason I would prefer hurricane ties, particularly the diamond plate over the flat twisted type. I did want to see what others think without being biased by my own thoughts. Unfortunately I may not have been clear enough in my original question but I do appreciate your comments. Thanks again.

 

Timberloks are installed through the double top plate and into the bottom of the truss. They can always be reinforced with any kind of Hurricane anchor.

https://www.fastenmaster.com/videos/...ide-video.html

 

As mentioned in my previous post, while I prefer diamond plate hurricane ties, the cost of any type of hurricane ties and structural screws is far greater than heavy duty structural screws such as TimberLoc. Where the building code may only require toe nailing I think it is prudent to provide additional fastening. I would point out the recent tornadoes in Ontario, Canada which have prompted calls to make hurricane ties mandatory. Depending on local conditions some other form of supplementary attachment may be satisfactory.

I will point out that the design of my building has no overhang on any side of the roof. The building is all steel clad and the siding on the gable ends is one piece from the base to the roof and on the sides, from the base up to the heel of the truss providing structural integrity between the walls and the trusses. This type of construction is typical in our area and I believe this is the way many pole barns all over the country are constructed.

I also pointed out that I was concerned about the effectiveness of screwing through the top plates if you didn't hit the center of the bottom chord. Thank you Xsleeper for pointing me to the dandy jig that FastenMaster offers. Again, thanks to everyone who has participated in this thread and contributed to a better understanding of the issue for me.

 

Further to my last post, I found a document, 'Truss to Top Plate' pertaining to this subject @: https://www.fastenmaster.com/product...ood-screw.html