Rafters on 20' 1-1/2 story

[Micky]

I was looking at the pictures of the First Day Cottages.  I really like how they did the ceiling in the loft.

http://www.firstdaycottage.com/pictures/interior/Interior03.jpg

My question is:  Can I put the collar tie on every other rafter.  This way I cold leave the ceiling open all the way up to give a similar look.  I think the First Day coattage uses 4' OC rafters and 2x6 T&G decking.  This looks nice, but I don't want the extra expence of the T&G decking and foam insulation.  I would like to use rough cut lumber for the collar tie every 4' and cover the bottom of 2x10 rafters with 1x T&G.  This way I could use fiberglass insulation and OSB decking.  It would have a similar look without the exposed rafters.

Jeff, I noticed you don't have any of these collar ties in your pictures?  I would think that the loft floor joists will take all of the outward force?

[JeffnTN]

I built my beams on 48" OC.

 I did the bottom of the  loft beams  at  96 " off the subfloor as spec in the plans.  I just mixed up the floor plan from there.

Shortened the loft to 12'4"  to accomodate my kithcen, bath, laundry below, and still have room for the spiral staircase .

 I left the rest of the area open for living room/dining/great room.  Raised the ceiling to an approx 18 1/2" wide flat spot at the peak of the LR.
Also added 2 ft to the length of the building making it 20x32.  Then added 2 ft to the length of the 12x18 to make the 12x20 MBR with the same beam desing as the LR only built up 2x8 instead of built up 2x12x SYP.


Left 54 1/2" OC between edge of loft for spiral stair, Then stepped up the collar ties flush with the top plate and beefed them up with 1x2 strips glued,clamped and hand nailed to accomodate my wiring for my track lighting,...

Hope this helps.............

jeff

[Micky]

I guess my first post was kindof confusing...  Here is my sketch based on John's plans.  As you can see, I am making the side walls 12' vs 10' to give more space in the loft.  This plans call out for a collar tie 7'7" high in the loft.  From your pictures (http://pg.photos.yahoo.com/ph/tnmtnbiker39/detail?.dir=63dc&.dnm=1cdc.jpg&.src=ph) it looks like you eliminated the collar tie over your loft.  I guess the beams are doing the same function?  If that is the case, am I OK without the horizotal 2x6 shown on the plans?   I am also planning on using 2x10 rafters vs the system shown in the sketch.

Your place is looking great!  It gives me something to get excited about.  Do you mind if I ask how many days you have been working on it.  I figure I am going to be able to work from April to October every other weekend.  Homefully I will have it about to the point you have yours now.

[JeffnTN]

my loft support beams ARE the collar ties.  

They are also my laundry room,kitchen and bathroom wal top plates.      Then I changed the height of the exposed beams in the Living Room=Great Room... in order to have a totally open floor plan.

[John Raabe]

Micky:

I have just sent you an update sheet for an open beam ceiling option for the 1-1/2 story cottage. It might give you the look you are after. The beams tie the rafters together at 48" o.c.

If anyone else has an older set of that plan and it does not have a sheet titled "Timber style open beam ceiling for 20' cottages" send me an email at questions@countryplans.com and I will send you the link to the update sheet (PDF).

[Micky]

Thanks for the great info.  It sounds like I am OK in  thinking that my floor joist does the same job as the rafter tie.  I am using the H-14 rafter bracket (as your recomended in a previous update) to make sure I have a good connection to the wall.  I was also going to use rough cut 4x12 floor joists and lag bolt these to the wall studs in addition to the ledger being lag screwed to the studs.

It looks like a sel-struc DF 2x10 will span the 10'.  Is there an advantage of going with the 2x12 rafters?

Also, you got me curious, when is a ridge board used vs. the plywood gusset?

Thanks again for the excellent resource and all the help you and others have been.  I have been spending most of my free time this winter daydreaming about building this cabin.  

[Micky]

OK, One more question.  I apologize if I am being too detailed driven.  That is my nature.  

What is the advantage of using the notching detail shown versus using a bird's mouth cut?  It seems like the standard bird's mouth cut would be simpler and give a couple more inches of valuable head room.

[John Raabe]

Notching vs birdsmouth: Birdsmouth will work too if you can get the nailing area needed.

2x12s were used to match the Dbl 2x6 trusses (this is why the peak is plywood instead of a ridge board) and to provide greater insulation.