1950s house remodel and addition
I’m an electrician by trade but am in the middle of a remodel and addition of a house in southern Ontario that we intend to live in with our family of 4. We are Climate zone 6b.
I will lay it all out for you and then ask a couple questions. I have done tons of reading but am having trouble deciding on a few things. The forum’s wealth of knowledge and experience would be greatly appreciated!
We are talking about a 2 Story house with block wall foundation and poured concrete floor in the basement. 2×10 4 ply laminated beam for main floor with 2×10 joists. 4” tongue and groove sub floor on the main floor.
第二篇故事是2×8位与旧箱子木板（大多是3/4“）的2×8梁，肯定会被更换！
屋顶是2×4个椽子，带衣领和膝盖墙。楼上的楼层突出了房子21“在各方面。所以这是靠在侧面的屋顶，地板托梁悬挂前后。
Outer walls are 2×4 framing with mostly 12” wide plank sheathing. Currently has vinyl siding which is to be replaced.
Addition is to be a 20×24’ garage with bedroom above.
我挣扎的最大的东西是外墙组装。最初我计划闭孔喷雾泡沫3“。外部的新型WRB，然后是外部绝缘和通风雨屏。可能有水泥板式水平壁板。它提出了我的注意，用CC喷雾泡沫的外部绝缘是否，因为它由于喷雾泡沫而不能向内烘干。人们的建议是什么？我不想在内部减掉更多的房间，否则闪光和贝蒂会很好地工作。另外，我最好用剥离和棍棒吗？我担心果皮，用这么多接缝粘在旧木板上。它虽然将提供一个良好的空中障碍。 What are your thoughts on header hangers to save on wood around windows and add more insulation?
第二大问题正在平整主楼。它变化最高为1 1/4“。2×10托梁附着在梁上，方形切出并坐在2×4上。似乎他们在附着点处于下垂。我唯一可以提出的是分离每个托梁，妹妹一小块并用双床衣架重新连接到梁上。想法？如果我走这条路线，姐妹的作品需要多长时间？底层有几个斑点贴在贴片上，我正在考虑在贴片中的存在后附加新的底层护套。你认为这是一个好主意吗？如果是这样，我应该拧到旧的底层或下面的托梁上。意图是有工程的硬木地板。
Next, the sloped ceilings on the 2nd floor. I intend to strap an extra 2” on the existing 2×4 giving a 6” cavity for cc spray foam. The roof sheathing is 12” wide 3/4“ thick planks. Is there anything to watch out for or is there a better way to insulate? Where the slope meets the outer walls it overhangs. Is it better to spray the overhang and soffit or put up a backer board flush to the sheathing and essentially extend the wall to the sloped ceiling and then spray foam? Any other ideas?
最后,房子有一个5岁的天然气炉is capable of heating the whole house. I am concerned with its ability to condition the space above the garage. It is 20×24 master bedroom with a walk in closet and master bath. I would love to put in a VRF heat pump\AC that could do the whole house and use the current furnace as an air handler and backup for extra cold times but i don’t think that’s in the budget. Currently i think the best plan is to use the furnace as is and if needed add a mini split to the room above the garage. Any concerns jump out to people? I will either run ducts to the garage bedroom under the joists and spray foam the underside of them therefore keeping them in the conditioned space or use floor trusses and run them through that.
Any and all help would be much appreciated!! I have attached some pictures in order to make things more clear let me know if you need to see something else!
Thanks so much in advance!
GBA Detail Library
由气候和房屋部件组织的一千个建筑细节的集合
答复
这里有很多东西可以消化，但我会在墙上装配：
蒸汽渗透完全粘附的房屋包装是一种善于使墙壁更加气密的世界，比1“封闭的电池泡沫闪光灯'BATT，以及闪蒸泡沫的额度的一小部分。
A full cavity fill of high density R15 fiberglass batts or rock wool would deliver about as much thermal performance as 3" of closed cell foam. Installing closed cell foam between studs robs it of it's potential performance. Do the math:
https://www.finehomebuilding.com/membership/pdf/184243/021269086NRGnerd.pdf
>"Next, the sloped ceilings on the 2nd floor. I intend to strap an extra 2” on the existing 2×4 giving a 6” cavity for cc spray foam."
对于屋顶组件，抢劫高/英寸泡沫的性能的热桥接问题仍然是相同的，但通常在较低的框架级分。在区域6中，只要至少有一半的R值是完全粘附的闭孔泡沫，在屋顶甲板的下侧面，可以尽可能安全地作为纤维。铣削2x4s只有3.5英寸，所以在2“Extender，你真的只有5.5”，而不是6“，并且磨2x2只会是5英寸。
而不是碾磨的2x2，考虑使用1“至1.5”泡沫板+ 1x粗糙“篝火条”，或者在最少地运行垂直于钉子的椽子的2x2s，并使用吹入绝缘或1.5“厚椽子边缘的泡沫板条作为热休息。请参阅：
https://www.finehomebauilding.com/membership/pdf/9750/021250059.pdf.
Assuming milled lumber and a 5" total depth, installing 2" of closed cell foam on the underside of the roof deck (R12- R14) and a compressed R13 (performing at about R11.5 at 3" compressed thickness) to fill the remaining 3" would be adequate for dew point control at the foam/fiber boundary. With 16" o.c. rafters thermally broken with R6 to R9 foam board on the rafter edges would outperform a full cavity fill of closed cell foam in a solid wood 5" rafter, despite the much lower R25-ish center cavity R. That's still a fairly low performance roof assembly for zone 6, but not a disaster. With the thermally broken rafters the ice-damming potential drops by quite a bit.
If possible, use much lower impact (and higher R) HFO blown closed cell foam rather than HFC blown goods, which has about twice the CO2e footprint of HFO blown foam:
https://materialspalette.org/wp-content/uploads/2018/08/CSMP-Insulation_090919-01.png
>"Last, the house has a 5 year old gas furnace that is capable of heating the whole house. I am concerned with its ability to condition the space above the garage. "
Almost all existing gas furnaces installed out there have crazy to even grotesque oversize factors for there actual loads. It's almost certain that your existing furnace has sufficient capacity, but getting the zoning to work will with the different heat loss characteristic of a room over a garage can be difficult. It's virtually impossible to get it to work well as a single zone, especially if it's 3x+ oversized, and it may make more sense to use a right-sized hydro-air handler running off the water heater to serve that zone.
To get a handle on the oversize factor of the "before insulation upgrades" version of the house, run this math on some (wintertime only) gas bills:
https://www.greenbuildingadadadyor.com/article/out-with-the-old-in-with-the- new.
如果超大的r is under 2.5x of the pre-upgrades house you might be able to at least heat the space using zone dampers with some level of comfort, but much more than that the duty cycle of the furnace will be too low for comfort, delivering the "hot flash followed by extended chill" during cold weather. At the ASHRAE's recommended 1.4x oversize factor the duty cycle would be (1/1.4 =) ~70% at the 99% outside design temperature, and off for only 30%. That's still enough excess capacity to cover the peak loads during a Polar Vortex disturbance cold snap.
禁止燃料使用历史，更好地描述位置（用于设计温度目的）和房屋尺寸可以采取可接受的设计负载来与现有炉的BTU输出相比进行合理的摇头。找到100-150K炉子的35-50k负荷，这一切都太常见，这肯定会加热房子，而是为了舒适的舒适。
For more on the comfort issues with oversizing see Nate Adams' freebie download chapters and short videos here:
http://www.natethehousewhisperer.com/home-comfort-101.html
http://www.natethehousewhisper.com/hvac-101.html.
http://www.natethehousewhisperer.com/hvac-102.html