Code-Compliant Shed Roof Assembly
Would this roof schematic comply with code? If so, what do you recommend for venting? 2:12 pitch climate zone 6. They are narrow twinhomes the TJI works great for the span and vault.
谢谢，
布兰登
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Top vented roof as you have sketched it is no the same as an vented roof. It can be made to work provided your warm side air barrier is solid and you use permeable roof deck and warm side vapor retarder.
用TJIS建造通风屋顶的最简单方法是将床单（房屋包裹，硬纸板或纤维板）固定到顶部法兰的底部，以形成通风口通道，仅在其下进行隔离。如果您使用的是不会阻止通风孔空间的高清板，则可以跳过上面的。
Even if you have to bump up your TJI one size, it would be cheaper than what you are proposing, you can usually increase the spacing between them to decrease the cost a bit.
您需要一种可靠的方式将墙壁屏障连接到天花板，有多种处理方法。
Thank you,
That’s absolutely cheaper. I’d leave the 14” TJI at 16” on-center and compress an R49 batt. I’ll check with local code to see if they allow reduced r value if it’s continuous above the top plate.
我已经看到顶板上用拉链胶带打开。还有其他建议吗？
r49 batts压缩至12.5英寸的R44大约是R44，因此可能不会飞。整个组装。在这种情况下，使用TJI的R44板可能会超过R38。
我还会在24oC上使用16英寸TJI的价格，这可能不会更多，而且更简单。
One thing with your current house design is that you'll have a hard time getting light to the center of the house. I would offset the two slopes add some clerestory windows like this:
https://i.pinimg.com/600x315/09/90/2b/09902b9c3d7da69ebdf3ee59fb668271.jpg
19.2” on-center is the most I can go with 16” TJI because the dwellings are 26’ wide. They are twin homes.
I share your same concerns about the light. To get a hallway to the back yard we needed the bedrooms on the back. We’re relying on a 4.5’x7’ full lite door/sidelite and two 4’x2’ windows to light the 300sq ft kitchen/living area. It’s not ideal but we’re doing the best we can with the goals for the project.
Thank you,
>顶部通风屋顶...可以使工作...
I agree, although there is the question of how permeable the sheathing layer has to be for each climate zone. In Z6, a guess is nothing less permeable than plywood (no OSB or Zip) combined with a class II vapor retarder and air barrier on the interior side.
For 2:12 pitch you'll need a second layer of underlayment, preferably felt. I would opt for steel vs asphalt shingle if the budget allows.
Venting isn't quite as effective at this low slope. Plywood sheathing would have better drying capacity.
我会与您的工程师联系。屋顶的在线桌没有假定的天花板。通过添加干墙，您可以使组件变硬并减少挠度。这通常可以使您进行更长的跨度。
19.2"OC is fine with dense pack but very hard to insulate with batts.
Thank you for the responses. Akos, that was a clever suggestion. I'm content using the 14" TJI because the cost jumps up almost $1/ft for the 16" TJI. How thick does the fiberboard or carboard need to be to hold up to the insulation?
I'm thinking:
-Shingles
-Two layers felt
-15/32" plywood sheathing
- iAsepace等于顶部法兰
- 纤维板/纸板安装在顶部法兰下方
-12'ISH“吹式高清玻璃纤维（R49）
One unit is 2:12 pitch and the other is 3:12 pitch
谢谢
我会与您的绝缘安装程序联系，纸板可能不会飞。由于坡度低，但是您不需要很高的密度。
如果您不介意一些沉降，则可以用低坡度安定下来，您可以松开山脊上的腔。在这种情况下，您几乎可以将任何东西用于挡板。