[seth]

I am ordering Pre-Fabricated Truss for my Patio roof from a Truss manufacturer. Size is 32X20 feet per design below. They are using 2X4, 24 OC total of 11 trusses. Are there any thing I should look for in terms of design/Specification or how the trusses are made? I find the Truss is a much cheaper way to install compared to the stick frame. Appreciate input from anyone who has knowledge of roof trusses. Thanks

 

[Thurman]

The drawing you are showing there looks like a modified "Howe" type truss to me. There are other similar truss designs such as "Fink" or "Pratt", and probably some new ones out there I have not seen yet. As far as what you should be looking at in the design or specs of an Engineered Truss-they are indeed Engineered Trusses designed for your special application. Their specs are correct. Without being disrespectful, how could you second guess them? IF your supplier is a trusted Engineered Truss designer/builder, then trust them. I have used these type trusses often and have had not problem with them. They are not only more "cost efficient" (not cheap) but easier to put in place and work with. Trust in truss, seth. Thanks, David

 

[Gary in WA]

Are you enclosing the gables? If so, order two stressed gables, if there is no wall or beam under them. Or are the gables sitting on a wall or beam, then order two studded, wall supported gables. Your plan you submitted to the Building Department will show the attachment to the walls/beams. Also the diagonals bracing required to keep your roof from racking in the wind. Follow your plans to keep anyone and visitors safe. If you will have overhangs at the gable ends, you may want to let the manu. know so they can beef up the gable's top chord for your notching of the lookouts. Be safe, G

 

[seth]

Thanks for the responses. Can you please explain what do you mean by stressed gable? The plan is to attach the roof framing to my existing wall studs of my home. They have to remove the siding. The gable will be supported by 3 6X6 posts on each side of 20 foot patio width. . Currently I dont plan to have any wall in any sides; No posts or beam along the length of 31 feet of patio. The truss will rest on a 9 3/4" LVL on the both sides (20' side). Totally 10 regular trusses with 24" OC and one gable end truss as below.

 

[Gary in WA]

If the gable truss is supported only on the ends, it needs to be a stressed gable. That is one regular (common stressed truss) with 2x4 vertical blocking added for siding application, either 16"o.c. or 24" on center, specified. I would get 9 regular (stressed) trusses and 1 stressed gable for the end away from the house. Before installation, after trusses are spread, stand and center a regular truss against the house and mark the top chord outline on the house studs. Then use 2x4's nailed there, (acting like a truss) and cut the tail overhang after the other trusses are set and nailed, after string-lining.

The last picture of a gable truss requires full bearing under the whole distance, not just the ends - beam or wall. Be safe, G

 

[seth]

Thank you so much GBAR for your suggestions

 

[Gary in WA]

You are welcome, that is good to hear that we helped. Any other concerns, feel free to ask, because it is free! Be safe, G