Glulam Beam Connections for 1.5 Story House
Hi All,
I am designing a house I’m hopping to get going this year. Its main envelope is a 36’x96′ rectangle running east-west with a cross gable in the center section going north-south, both roof pitches being 8/12. The center encloses a combined great room that includes the living room, kitchen, and dining room with a vaulted ceiling. The upper 1/2 story consists of a partial loft in the center and bonus rooms on the ends. I plan on using 14″ TJIs for the rafters and have sized glulam beams to holds them up for the 30psf snow load of my area. Below are some rough drawings. There is a 3D model here: https://grabcad.com/library/draft-house-framing-1. Click on the “Load in 3D viewer”. You don’t need to download anything, just click the screen and move to rotate the model in the web browser.
Some questions I am seeking advice on.
1. I have the 51′ load bearing ridge beam that runs north-south continuous, the main roof’s drop beam is directly under it running perpendicular which supports the north-south ridge beam and the main east-west ridge board. The idea is this would keep things simple and strong with minimum brackets/connections. That being said I’m assuming it would still need some connections for uplift. Is there a better way of doing this? Note that I am trying to avoid a post under this apex for the sake of the floor plan hence its offset as shown, and the drop beams along the main roof line require two different sizes as far as loading goes.
2. Regarding the apex where the two main roof lines meet I am having trouble finding any off the shelf hardware for the connections. The closest thing I have found are the GLS/HGLS hangers from Simpson but they appear to be custom order parts. I presume I also need something to prevent uplift of the north-south ridge beam? Are there some other brackets or connection methods I should consider, or new design altogether? I’m hoping to use off the shelf parts as much as possible.
3. The north-south roof line has a 12′ overhang to shade the south windows in the summer. I used Forte software to size glulam beams from Weyerhaeuser and it limits overhangs of glulam beams to 7′. Thus I am planning for an exposed beam truss 5′ from the exterior wall. I’m coming up blank for a good design for the connection points where the eves of this overhang meet the 4/12 pitch roof and its wall where the truss and load bearing sub-facia would need to transfer their loads to the ground. Any ideas?
4. For the beam truss discussed above in #3 I am hoping to fabricate on site as I have not found any local suppliers for this yet. Any off the shelf connections to consider to make this happen?
5. My jurisdiction uses IRC-2012 and I have meet the inspector and he seems very reasonable. I have an engineering background but obviously not related to architecture however I feel comfortable sizing everything and making any necessary load calcs. Any ideas to keep this from needing the plans for this stamped welcomed. At this point I’m not willing to loose the vaulted ceiling. If need be I’ll finish the design and hire someone to fine tune and stamp the plans.
Thanks,
Adam
Replies
Your local Simpson dealer is your friend. They have a huge catalog and can usually find what you want.
Your local Simpson dealer is
I spent an hour poring through their 388p catalog as well as the one from USP. Like I mentioned GLS/HGLS hangers they sell look like they could work but they appear to be custom order parts. I'm really looking to use off the shelf parts and what is the best practice way of doing this. I'm going to stop by my local lumber yard to day and see what they can recommend.
You can only use off the shelf parts that exist. If they don't and Simpson will make them for you jump in the air and kick your feet! Otherwise you'll have to have a local engineer do them for you, seal the plans and submit them with your permit app. I've done it both ways and ther Simpson route is far cheaper and probably faster.