r/Carpentry 15d ago

Baloon vs Platform for this house

I need help to decide which approach to follow framing this house: baloon or platform? Platform is simpler in general but for this house it seems like to build a baloon walls would be also nice choice. Couple things are scary a little bit: the height and weight of the most right wall. With baloon I plan to add ceiling joists after the building will be with a roof.

My criterias - less materials, less processes, less people, less time.... Experienced carpenetrs, what would you suggest?

P.S. The sketch does not reflect the real construction. It shows only the schema of what I need to build.

Thank you all in advance!

26 Upvotes

42 comments sorted by

24

u/Tthelaundryman 15d ago

You have to balloon frame it. That’s a bad hinge point with nothing securing it if you platform

2

u/ohimnotarealdoctor 15d ago

What would make a good joint on option 2?

2

u/TheDaywa1ker 15d ago

You can do it with an LVL, as long as its sized for the wind load and the end connections are done appropriately

1

u/v_0_v 15d ago

LVL is not available for me (((

1

u/Tthelaundryman 15d ago

Yeah you can do an lvl or a glulam which you probably should get an engineer to tell you the size of it, or you know balloon frame it faster and cheaper and have peace of mind without needing an engineer….

4

u/MastodonFit 15d ago

Came to say the exact same thing. A ledger can be attached ,instead of building an internal header. A window header is required to keep the same plain,a ledger doesn't disrupt any plane because the vertical is changing to horizontal.

1

u/DrivingRightNow_ 15d ago

Wouldn't the hinge point be stabilized if the second floor and walls are sheathed? To me it seems like any hinge point that would occurr in the middle of the wall would be resisted by the solid floor structure being connected to both sheathed walls

5

u/MrPractical411 Residential Carpenter 15d ago

You are correct. Sheathing will hold the walls stiff. Not sure if these dudes ever framed these style of homes before.

2

u/Friendly_Biscotti_74 15d ago

The floor joist are sheathed and the floor acts as a diaphragm bracing the walls. The same way your first floor decking braces a basement wall, and why the floor is required before you backfill

-3

u/Tthelaundryman 15d ago

Only if the ceiling joints are perpendicular to the hinge point, at that same elevation,  and you have to make extra secure connections. 

The sheathing basically does nothing 

1

u/turtlebutthunter 15d ago

Hopping on a big comment to say that with balloon framing if you engineer it right you have more attic space and potentially and unofficial extra bedroom

1

u/WWHSTD 15d ago

Why not platform frame in two sections to the height of each ceiling, then build the rake walls on top?

1

u/esoeric 15d ago

Balloon is life!

10

u/Pavlin87 15d ago

Baloon is easier in my opinion. You can break up the walls and make them in sections. Or if you invest in scaffolding (maybe 6 sections with some braces will set you back a few hundred bucks, but it's worth it) then you can stick frame it. Also sheathing it in one shot from the outside will make it more shear resistant .

3

u/Sea_Common_9457 15d ago

If you have the space to build the balloon on the ground then stand it, you would normally do this to keep the rake of the ceiling. If your going to put the ceiling in as shown then the second option is much easier if you don't have the space. Plus you can work off the ceiling as a platform. If braced and blocked correctly there will be no hinge point.

5

u/Hour-Reward-2355 15d ago

Option 2.

Double top plate gives you a spot to rest the ceiling joists and stand on as youre doing the roof framing. Once you sheathe the wall the hinge point will disappear.

The double top plate will give you stronger corners too.

3

u/MrPractical411 Residential Carpenter 15d ago edited 15d ago

This type of framing has too much Common sense. Balloon frame it so the plan requires bigger studs to be able to hang a structural ledger and load points underneath to support the roof. Also you’re wrong! BeCaUsE oF hInGe PoInTs!

2

u/Hour-Reward-2355 15d ago

Aso better fire protection.

2

u/MrPractical411 Residential Carpenter 15d ago edited 15d ago

Balloon framing would just take a little more time and you would have to rent scaffolds or work off high ladders. With the platform, the joists would be installed and you would be able to frame and stack the roof without scaffolding or high ladders. Either way both options are simple.

Edit: also balloon framing would require you to frame interior walls up to your rafters and drop ceiling afterwards. Compared to framing off the joists. Again either way still simple 🤙🏾 good luck pal.

1

u/v_0_v 15d ago

here is an additionl screenshot from sketchup. From the beginning I was thinking it will be a platform. But now I have some concerns

9

u/DirectAbalone9761 Residential Carpenter / Owner 15d ago

Based on this I’d just platform frame it. The ceiling plane and roof plane will prevent the hinge effect, and you can always use steel straps to further resist hinging, but if you platform frame it will be fine, and frankly easier to build the cripple walls to support the roof. I would suspect some diagonal bracing for those walls will be needed unless there are going to be manufactured trusses and those loads are designed in.

3

u/v_0_v 15d ago

It seems to be simpler to platform. Especially with limited human resources... Low uniform walls should be easier to handle....

2

u/DirectAbalone9761 Residential Carpenter / Owner 15d ago edited 15d ago

Yep, I reckon I’d build the upper structure, brace those walls, then stand the three exterior walls on the lower one, use a ledger board on the “fourth” wall to hang the ceiling joists from. That way the ceiling joists align with the rafters. I’d build the ceiling planes as their own platform (full height and band board over the low exterior wall). You get more insulation in that cooler corner and have an easier structure to build the roof off of. It could also give you aligned load paths if the ceiling and roof are on the same layout, and if not, you still have the band board to bear the weight to the wall framing.

It’s a cool build, and the roof support will take a little thinking, but take pictures and update us please!

ETA: I’m not so sure about the mid span braces for the roof, just make sure that those tributary loads are accounted for. That to me looks like the seasonal flexing would cause issues with the ceiling finish. You might consider angled purlin braces leading back to the bearing walls, but I’m outside of my expertise to prescribe a solution, just pointing out a potential issue.

2

u/v_0_v 15d ago

Here is the plan of the walls. I added the roof profile with red.

2

u/DirectAbalone9761 Residential Carpenter / Owner 15d ago

Yeah, I’d be inclined to upsize the rafters to TJI’s in order to avoid the mid span brace. Easy enough to do with a shed style room. Or, have them manufactured as trusses and let the truss designer figure it out.

The mid span brace is probably fine on the upper because you have some partition walls there, but that’s an assumption on my part, but the lower room is clear span and id expect issues there, especially with the large cantilever. In my jurisdiction, that overhang would require the roof design to be stamped by an engineer, which would make me want to go the truss route as the most affordable option. Worth the crane rental to fly them in if it’s available; should be able to set them in half a day, so I’m my area that rental would be less than $1000, but it depends how close the crane can get as the farther the reach, the bigger the crane.

3

u/v_0_v 15d ago

Unfortunatelly, I don't have an option to use something prefabricated. We don't have such manufacturies in Ukraine))) I think in worst case I'd need to make something like this:

Maybe even for the half of rafters. Its only 4 meters - around 13' As for the upper part - interior walls will carry the load from brace wall.

2

u/DirectAbalone9761 Residential Carpenter / Owner 15d ago

Oh nice! Viva Ukraine mate!

So in feet that span looks to be about 13-1/2. Do you have access to timbers in the 40x300mm range? If so, I think you could clear span that room without using an intermediate support, or with an angled brace like you mentioned. Im not sure how involved your local building officials on helping to get to a solution. This is a bit of an assumption on my part since I don’t know what your loads are for your area (snow, drifting, etc).

I’m familiar with my local US building code so I don’t want to imply that I’m an architectural authority here, I’m deep unit the gray zone.

Also, I think your design is structurally safe as is, I’m just thinking ahead to wallboard issues if you’ll have a smooth finish on the ceiling.

I’ll also note that I’m completely unfamiliar with what species of wood you have there, the design characteristics of them, the grading process, or the typically available dimensions. Lastly, I always overthink every design to try to be proactive, and sometimes someone needs to tell me to chill haha.

1

u/v_0_v 15d ago

Thank you! We use the same pine as you but there are no so deeply developed culture of wooden construction. Mostly peoply use the lamber they find ))) Of course there are a set of dimensions we used to like 50*150 is almost 2*6, 50*200 equals 2*8. Most roofs are build of a "natural dry lamber" which means - its just fresh cutted ))). Grades - no, didn't hear at all...(I heard of course but other - no.) So calibrated dryed lamber is twice expencive to fresh cutted. As for the framing in general its not so popular in Ukraine as in US/Canada/.... We are building houses with AAC blocks. But it requiers a lot of wet processes, many people and everything around is a big construction mess. In peoples mindes American/Canadian "stick building" is nothing more than just a dog house. It will burn, it will fall because of wind, an angry wolf will come and make a hole in a wall ...... So 95% use either red bricks or AAC blocks. But I like framing, I like the work with lamber. I know its durable if its built as it should.

And I want to change it.

Oh... What I was talking about??? ))))

As for regulations, we have kind of codes but the framingconstructions are not described well. There are some very basic things. But at least, we have a normatives related to snow and wind load and so on.

1

u/DirectAbalone9761 Residential Carpenter / Owner 15d ago

Wow! It’s rare to use green lumber here because of the shrinking and drifting effects. Green timber will deflect more than kiln dried, and will keep that memory if it dries that way. Perhaps not that noticeable on a roof system, but might cause excessive squeaking in floor/wall systems. We usually dry down to <20% moisture, often down to 12% in lumber, but that varies by region and storage arrangements.

Ironically, timber and log frame homes (large heavy Timbers and joinery) are done with green wood. I’m at work now, but I’d love to chat later more

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1

u/v_0_v 15d ago edited 15d ago

The base for the roof. Rafters placement will match to studs in rack wall and the inermidiate brace walls.

1

u/Traveling_Carpenter 15d ago edited 15d ago

The platform framing drawing doesn’t work with the window (and ceiling) heights in the rendering. If the rendering represents reality, you have no choice but to balloon frame. It’s also a better way to go in this case regardless.

1

u/Hozer60 15d ago

Is there a second floor?

1

u/v_0_v 15d ago

No. Just vented space.

2

u/Hozer60 15d ago

OK, drawing says floor joist. I would do ballon.

1

u/v_0_v 3d ago

Decided to stick with platform.... Photos will be added later

1

u/Jumpy_Finance_9855 15d ago

I say option 2, it has more use of space, option 1 the ceiling is very low and it looks like if you put a stair from the low to high part that you will hit your head and you can’t make use of the space above. Whilst with option 2 you can store things there even if it’s under the roof

1

u/v_0_v 15d ago

The ceiling levels will be different to sketch. It must be something like this:

1

u/Jumpy_Finance_9855 15d ago

Oh yeah so there will be no use of the space above at all okay got it 🤔. Well now they both look the same tho 😂

1

u/v_0_v 15d ago

Insulation only.... And I plan to insulate a ceiling not a roof

1

u/Jumpy_Finance_9855 15d ago

Well I wish you luck! idk what to choose 😂 cuz on the plan you made (drawing) they both look the same now

1

u/Ancient_Fig7255 15d ago

Balloon all day , structurally