Floor Truss to Mudsill Connection

[bozobozo]

Are there any specific requirements out there for connecting floor trusses (3 1/2" x 16") to the mudsill? Ditto for where the floor truss crosses intermediate bearing walls. House will be located in Bethel Township, Lebanon County, PA.

 

[steveray]

If there were, (and I am sure there are) they should be spelled out on the truss drawings....

 

[bozobozo]

The flooring truss plans just say "provide mechanical connection (by others) of truss to bearing plate at joint(s) ..."

To me the is wide open, a nail is a mechanical fastener.

 

[pwood]

get a copy of the truss manufacturers installation guide when in doubt.

 

[steveray]

Sounds like partial engineering to me.....the braced wall panels need to transfer their forces to the foundation (usually through the floor system and box) and sill connection...ask who the "others" are and make them prove it!...

 

[Papio Bldg Dept]

I agree with Steve. If the truss manuf.'s engineer isn't providing the connection details, then building's structural engineer needs to.

 

[bozobozo]

I have gone back to the Truss Manufacturer and asked. If they do not I will have my engineer make the call (each time I ask him a question, I see $$$$ flying out the window)

 

[Architect1281]

When you use trusses or Pre-engineered lumber and increase span and therefore endpoint load reactions you go beyond prescriptive load path and attachement schedules and enter into the world of WFCM so math skills are then required. and if the math gets hard enough the professional documentation could be necessary.

 

[ICE]

Engineers need to eat too.

 

[Jeff H. Whitley]

By code (IBC/RBC) the truss manufacturer is REQUIRED to calc all Truss to Truss Connections. Truss to plate on the other hand is NOT required, not yet any way. Part of the rub is, if it's spelled out on the sealed drawings then that EXACT connection has to be used, eliminating your options. Therefore most truss suppliers provide that information separately on documents which have not been sealed. Invariably, if it's speced out on the seals it’s not what the contractor/home owner wanted to use for this particular job.

Calculating truss hardware is easy.

Roof Truss:

You have to use two bits of information found on the truss engineering drawings. Both should be found near the "Bearing" information block.

1- The Reaction

2- The uplift ( proceeded by a negative number)

Floor Truss:

Same procedure except you don't need the uplift values since there are no wind load calculations on a floor. Item “T”

Next Choose your hardware supplier:

Simpson Strong Tie ( ITW/Alpine they are not gonna buy from their competition)

USP (used with most MiTek engineered trusses, they own the company now)

The manuals are available on line and give you a graphic for the correct application, be careful here. You don’t want to choose hardware that is hanging in mid air with nothing in which to nail into.

For your Floor Truss with a single plate:

● Choose the correct application in the hardware catalog. (Attaching member, concrete or wood)

● Verify both the truss and the member being attached to is the correct application.

● Under the 160% (SPF) column choose a reaction/uplift that is equal or greater than the respective values on the truss engineering drawing.

● Check the chart for the correct size and qty of nails, being sure when you install, be sure to fill every hole.