CLT stair flight connections?

[Agent666]

Hi all, does anyone have any experience with attaching CLT stair flights to landings? I've been trying to find a idea of how they are typically detailed but it's like it's some state secret that no one letting on about.

I'm talking about the connection at the top of a flight to the main or midheight landing, like shown in this image from Google. Somehow drilling some long screws sideways just doesn't seem that robust, nor does sitting on a cutout ledge/key given the rather thin landings.

Anyone done before and willing to share?

https://engineervsheep.com

 

[ProgrammingPE]

Here's an example connection I found by XLam.

Structural Central

http://www.structuralcentral.com

http://www.youtube.com/channel/UCOj2mXXf3ZbZtgxTc6BtkGg

 

[Agent666]

Thanks ProgrammingPE, I must admit I did find those as one of the only examples I did come across. But they are a bit odd from an engineering perspective and I thought some person from marketing was employed to draw them as they have some clear issues from an engineering standpoint.

Yes they have a support member under, which is not present in the photo I posted, but also given the perp to span laminations are basically useless for flexure or shear, the whole landing and stair support is pretty much sitting on one single parallel lamination, that just doesn't gel with me that that is any way going to be acceptable or work to someone who likes their load paths.....

Both details have all the landing reaction load being carried by a single lamination.... smells fishy to me. Neither would work that well without the beam/support in any case I'd say.

I concluded these details were likely dreamed up by some marketing illustrator or a failed engineer who could only get a job in sales or something (sorry if anyone is in sales), rather than being a serious contender for an engineered connection.... but maybe that's what they do. If they do, I'm officially not impressed.

If anyone has a real-world connection details they have used, which they are willing to share I'd be grateful.

https://engineervsheep.com

 

[ProgrammingPE]

Keep in mind, though, that this is a continuous piece of wood, like decking instead of stringers. 2x12 joists @ 12" o.c. would have the same amount of area for shear as a single lamination that is continuous.

Structural Central

http://www.structuralcentral.com

http://www.youtube.com/channel/UCOj2mXXf3ZbZtgxTc6BtkGg

 

[Brad805]

It would not surprise me to see something like the image below being used. Most CLT is machined on large CNC, so achieving accuracy is not a big deal. We have used those and they are not overly complicated to work with provided you have a team that pays attention.

 

[molibden]

Option with steel elements.

Can be done without steel, just self tapping screws with whole thread. Screws at an angle from both sides of the joint, CLT cut with small step joint for easier assembly.

 

[Agent666]

Thanks, makes sense.... Time to put some numbers on a few options on my end I guess, and see how it pans out.

https://engineervsheep.com

 

[bones206]

Well if that scarf detail was dreamed up by the marketing guy, they went ahead and used it! This is from their website:

 

[Agent666]

Thats some strange bracing, maybe the marketing guy did that too?....

https://engineervsheep.com