Truss diagonal bracing

[23vc]

Hi
I've got trusses to put up for my extension, the ceiling span is 7m and the roof width is 3m. According to the truss plans I need the do a "X" diagonal bracing each side of the roof, so the diagonal braces need to cross over each other. I'm trying to understand the detail for intersecting them, I've seen stuff about using a 600mm splice plate to join them but can't seem to find anyone who stocks such a thing. If anyone's ever done this and got any pointers it'd be much appreciated as always!

 

[tony1851]

Just use something like 100 x 25; they will obviously bend a little where they overlap, but as long as each brace is securely nailed to the trusses, it will be OK.

 

[23vc]

Really?! Yeah the bracing is 100x25ish.
That sounds almost too good to be true, but I'm not complaining!

 

[^woody^]

You don't splice the bracing, you lap the timber over two trusses - ie put the one timber next to the other not on top of it.

Two nails per truss fixing

https://www.trada.co.uk/publication...uopitched-trussed-rafter-roofs-for-dwellings/

It is normally a W pattern, not an X, so no over laps.

 

[23vc]

Thanks woody, yeah I wanted to do a W pattern but because the roof span is twice the width, the diagonals would be nowhere near 45 degrees. So I think I need to go with Xs. But if as Tony says I can just cross em over bending one across the other then it's not a problem

 

[^woody^]

You dont do any X's!

 

[23vc]

So if I do what I've sketched (badly) below, that's what I'd like to do, but it's my understanding that it's not valid as they're at nowhere near 45 degrees as it's such a narrow roof. They're at more like 22.5 degrees if you see what I mean

 

[^woody^]

Where are you getting 45° from?
You brace from one corner to one corner under the top chord (rafter) and from center to corner on the bottom chord (tie), and then across the trusses at 90° at each junction of the chords and braces (ie whereever there is a nail plate)

 

[23vc]

From the doc you linked to above

Top left corner of screenshot = says 45degrees
Pic in bottom right corner = mines a 'narrow fronted roof '

Tempted to just do as you say, but definitely suggests otherwise in the doc

 

[chappers]

where the two braces intersect, just split one of them into two and then put a splice in over the intersection making sure it covers at least three trusses including the one its bridging

 

[23vc]

Thanks can the splice be another of the same bracing wood or does it need to be steel or something?

 

[John D v2.0]

Same wood is fine