Jack and Corner Jack Connections HVHZ

[Antnyt23]

Been trying to get ahold of the building department to get some clarification on sections R4409.8 (FBC 2321.7) for the connections of wood trusses to wood trusses in HVHZ's but have not had much luck.

was curious how others handle it if they have worked in the area. The main section I am looking at I have pasted below:

2321.6 Anchorage to wood.

2321.6.1
Anchorage designed to resist uplift forces, securing wood to wood, [highlight #FCE94F]shall be steel straps nailed to each member[/highlight] and shall be designed to resist uplift forces set forth by the design professional. Straps shall be approved under the criteria set by the certification agency. All anchors and relative nails shall be galvanized.

2321.6.2
[highlight #FCE94F]As an alternate to using straps described in this section, the building official may approve other anchorage submitted by a Florida-registered architect or a Florida registered professional engineer[/highlight], proficient in structural design, provided that the information set forth in Section 2321.7, Items 1, 2 and 3 submitted in connection with such anchors and such anchors and the proposed assembly otherwise comply with the requirements of this code.

2321.7 Testing of anchoring.
Anchoring required by Sections 2321.5 and 2321.6 shall be tested under the following criteria:

1. Concrete to wood straps: Minimum design uplift load 700 pounds (3114 N), with four 16d nails with upper end bent over truss chord and nailed. Nails shall be clinched. Anchors shall have devices to hook into upper tie beam steel and embedded a minimum of 4 inches (102 mm) in concrete.

[highlight #FCE94F] 2. Wood to wood straps: Minimum design uplift 700 pounds (3114 N) with four 16d nails in each member.[/highlight]

3. Other anchors: Minimum design uplift 700 pounds (3114 N).

4. The criteria stated in Section 2321.7, Items 1, 2 and 3 above, are minimum requirements for product approval for the certification agency. Anchor design and uplift forces shall be submitted to the certification agency for approval together with sufficient documentation and test data to verify performance. A product approval shall be maintained at the job site for the inspector to compare with the uplift force requirements of the design professional as shown on approved plans.


So my question is (based on what I highlighted above) Strapping is required as a minimum unless another connection is shown to be able to resist the uplift.

this would pretty much rule out Toenailing corner jacks due to strength based on a lower DOL <1.6 for wind in some of these areas.

Now I have heard previously that strapping is not adequate for that hangers are required in Miami-Dade. I am curious if there is a code reference I am missing that requires strictly hangers in lieu of strapping?

Also just in general if anyone has worked in this area in a similar situation how have you handled jacks and corner jack connections.

 

[southard2]

OK I'm in Florida like you. I've never really even read the residential building code. But when I first read 2321.6.1 above my take was that they are talking about a roof clip like a Simpson A34 or A35. I don't see how a strap could make the type of connection you are talking about.

Section 2321.6.2 basically means you can engineer the connection and that is pretty straight forward. In the general notes on my projects I delegate out all truss to truss connections to the truss design engineer. The engineer of record however has to design the truss to wall connections since those connections involve out of plane and in plane wind shear loads.

2321.7 Testing of anchoring..... Well as for this section I would not worry about it as you are going to need to use a Florida Approved Product anyways (like Simpson or Hughes) and they will have already met this criteria or another acceptable criteria that the state allows.



John Southard, M.S., P.E.

https://www.pdhlibrary.com/

 

[Ron]

Agree with Southard2 (btw John....where have you been?)

They are talking about something like the Simpson H/TSP strap, or similar. That's a one-side strap. They also have a double side strap that wraps over the truss chord. The style will somewhat depend on your truss bearing point on the wall.

In 2321.6.2 they are talking about something called a "local product approval". This process increases your liability. If you can use a manufactured product from Simpson or Hughes that already has Florida Product Approval, do it!