Roof truss termite damage repair

I am looking for a little advice on a section of damaged roof truss resulting from termites in the house from sometime unknown in the past. I have a home built in the late 70's with what I believe is a "howe girder" truss system that spans the 30 foot width of the house, which to my current knowledge lands on NO load bearing walls...this is strange I know and someone tell me if that makes no sense, but I have seen several variations of the same house in the neighborhood with WIDE open spaces and no walls in huge sections of the house.

Anyways, I have found two small sections of termite damage where the wood in the truss is brittle to the point where I can grab it and it will crack in my hand. It's no completely destroyed, but it can't be doing much in terms of support. My question is about repairing this. The largest section is probably 4 feet long that is damaged. I know I can't just cut out a section and replace it, because that may mess with the structural integrity. Can I add a sister 2x4 to that large of a span?

Here are two photos of the structure in question:

The first photo there is the damaged piece, you can sort of see the crack in the center of it, but the whole piece is brittle. The second photo shows the left side of the house and the structure of the truss. The bottom 2x4s meet at the middle of the house with a brace and are supported by the piece above.

Any advice on how I can repair this would be great. Or if I need to abandon my fun and ask an expert...thanks!!

 

Hi Zack and welcome to the forum,
I'm far from an expert but I'll make some comments, since I can't sleep.
First, how did the termites get way out there to the middle of that truss. We don't know where you are, but my east coast termites build tunnels either through the wood or mud tunnels over it. I'm suspecting that whatever brand of bugs you have, have done a lot more damage than just what you are seeing. They might eat their way out there, but I doubt they decided that section of wood was better than the rest.

Once you determine the extent of the damage and hopefully it is minimal, then you can address the how to issue.

There is also the slim chance that the section in question was damaged before it was built into a truss. Perhaps it has been that way from the start?

Just some thoughts,
Bud

 

You would need a structural engineer to look at, and give you the best advice on the proper repair of this damage.

If you want a non-structural engineer's opinion, I would say you could cut out the damage, (assuming it is so bad that it is like paper, and would crush) put a new piece in, then put longer pieces (say 8' longer) on either side and bolt them together every 12" or so with 1/2" x 5 1/2" bolts and washers. But like I said, you should get someone qualified to look at this before you do anything.

I'm still trying to figure out why the drywall and ductwork is under the truss. Its also making me wonder if this is not termite damage at all (are there actually tunnels?) Or if this is moisture damage from the air conditioning duct being in contact with the wood.

Not strange, at all.. that's why trusses were invented and it's how they work. All interior walls are non-load bearing... only exterior walls are load bearing, unless the truss is designed in such a way that it has a load point and needs a load bearing wall. This is also why you shouldn't mess with it if you don't know what you are doing.

 

Thanks for the thoughts. A little more info from me:
- The house is in arizona, I recently moved in. We know from the previous owners that there were termites in the past. But yes, I agree it doesn't make sense that just the middle of the truss is damaged...I will have to try to examine it a little more.
- The ductwork underneath is because the house has a soffit section that the ducts run through where the ceiling is lower in the middle section of the house. I had automatically suspected termites, since the previous owners treated for them, but maybe it does have something to do with the ac duct.

I'm leaning towards hiring a professional, I'm just cheap and feel like this is going to be straightforward to fix. I'm just uneasy because it is structural.
I'm curious about xsleeper's idea. I think this would work logically, or even if I did the longer support board first, then cut the section out, replaced it, and button it in, so that at no point there is completely nothing there. I just don't know if this is acceptable, so again I will likely hire a professional at least for the advice.

Thanks again for the thoughts.