Generic wood I joists

[charliealphabravo]

I'm looking at these wood I-joists in a residence and I can't find a manufacturer's stamp anywhere. I had thought that I-joists were only available as engineered components and/or with manufacturing marks.

Does anyone know if these could have been purchased as generic commodity components like dimensional lumber? I don't think they appear as such in Part 9 of the ABC. Location is Alberta.

 

[jayrod12]

Are you wanting to know for your own curiousity, or because you want to check capacity?

 

[charliealphabravo]

I haven't been asked to say anything about them yet. They are remaining from a house fire and seem to be undamaged. If I think there will be a problem incorporating them into the rebuild then I might flag it now.

TIA

 

[txeng91]

I guess it’s possible for anyone to make them. NDS refers to manufacturer data for design values, and without knowing the grade of the lumber used it would be difficult to calculate the exact design capacity. So I’m not sure if they should be reused if the loading conditions are going to change. Also they should have web stiffeners over the support beam.

 

[Ron247]

I have seen "unmarked" joist similar to those in the US but did not know where they come from. I generally find markings very easily but I have also seen a few that were totally unmarked. The web stiffeners noted above are called "squash blocks" here. They may not be present on 1 story houses but are more common to find on 2-story.

I do not know if manufacturers have "seconds" they sell and do not mark. As a carpenter, I used to see below grade plywood that was not marked. It was called "blows". Sometimes the plys were OK, but the sheet was manufactured out of square. Sometimes the plys were not glued together well. This was in the 70s.

 

[NorthCivil]

This seems like a good question for KOOTK, this is his practice area.

I would be inclined to say that the joists have in service history (proven past performance). while you may not be able to determine their make, they have proven their performance, arguably

 

[KootK]

This seems like a good question for KOOTK, this is his practice area.

I can't add much I'm afraid. We're a bunch of cowboys in Alberta. I visited i-joist "plants" in the late 90's that amounted to some dude and his wife squeezing flange and ply together in the back yard by running it between two tires set up as bumpers. And don't even get me started on our impressive variety of open webbed steel joist products... Alberta is where RTU replacement jobs go to die.

 

[Jerehmy]

I visited i-joist "plants" in the late 90's that amounted to some dude and his wife squeezing flange and ply together in the back yard by running it between two tires set up as bumpers.

I love it.

First I'd find out how old the building is. Then I'd measure exact flange sizes, this should give you a good idea of when it was manufactured too. Then I'd call local distributors to see what manufacturer they may have stocked around that time. Kind of weird there's no stamp though. How many joists are we talking? If theres like 100+ could always remove 3-4 and testing to failure for flexure.

Could also find out who built the building and see if they know what joists they used if they're still in business. Probably used the same manufacturer for all their projects.