bridging two trusses for skylites

[wjvsr]

Hello. I'm Bill. I have modified queen style trusses spanning 36ft to outer bearing walls, 2ft o/c, constructed of 2x4 members.These trusses also cross over a 2x6 bearing wall between the garage and kitchen that is 2ft off the center king post to the peak in that area. I want to install (two) 2ft wide skylites over the center of the kitchen. The location of the trusses there would have them off center. I was considering beefing up the two trusses on either side by adding 2x8's from the lower outer wall all the way up to the king post and also incorperating that middle bearing wall in some way. Then after modifiing them, build doubled headers to connect these two trusses across on both ends, then recconect the two that I cut a section out of to allow for the opening of the skylites. Also I would put a new doubled center cord across ( just on top ) for framing the skylites at the roof. Having said all that, I do understand that there are load points that trusses are designed for and I do not want to do any thing to jeapordise the structures integrity. I did build this house 18 yrs ago, however am not sure what the best course of action is here. Any helpfull ideas or comments would be apprieciated. Thanks!

[XSleeper]

Your best bet is to have a structural engineer approve and sign off on any truss modifications. That's what you pay them for... to figure out if/how modifications can be made, and then they have the responsibility if such modifications fail. I highly doubt that this is the kind of advice you can get for free / sight unseen.

[chandler]

To further Brant's comments, stapled to your trusses were the explicit instructions to NOT CUT the trusses at any point. With that said, a structural engineer would have to put himself out there for approval. I know it isn't what you wanted to hear, but it is the best advice we can give.

[BridgeMan45]

And speaking as a licensed P.E., I know I wouldn't so much as suggest adding a staple to any truss, without the (written) blessing and approval from the truss manufacturer. Too much to lose, with only a few $$$ to gain.

[chandler]

We just installed a prefab spiral staircase in a basement for a client, and it required us to cut the bottom chord of a 24" truss. It called for us to beef up the truss with double 9 1/2" LVL sitting on vertical structure to the floor. Luckily it was only a 6' opening with walls on either end and it was overkill, but you can't blame any failure on the part of the engineer. Install the LVL, do it right, hold your breath and cut the chord. Aaah, no movement. Good feeling.