[Crafty42]

Hi all,


I've been working out plans for what seems to be years. Ok, maybe just a few months. The plans I originally purchased had a 20'8" (outside to outside) foundation wall, and a 22'4" long Great Room. At the end of the Great room is aloft with floor trusses running perpendicular to the ridge. The plans originally had a pass through fireplace opposite the exterior wall that would act as a ridge beam support. I've moved the fireplace and don't want to pass a support pole down into the basement and up to support the ridge beam, so I've been toying with options....


Option 1: Use Scissor Trusses. 12/12 outside pitch and 10/12 inside would still give me a nice room.


Option 2: Parallel Chord Truss. Wasn't real keen on these, but mostly from lack of ever working with them.


Option 3: Ridge board with rafter ties. Not sure on the requirements here. I couldn't find where IRC 2015 (my areas code requirements) where it actually says what the on center would need to be for rafter ties. I've read it's every pair of rafters, which means I would have a rafter tie at most on 2 foot on-centers. I don't want that in a great room.


Option 4: Might not be cost effective, but coult I use some sort of timber truss on a stick frame that would allow some nice looking rafter ties and space them out further?


Options 5-X: This is where I would like to hear some thoughts on a way to make a nice great room without running a post through the middle and needing equipment to hoist a 500 pound ridge beam up into place.


As this is a DIY project, I'll won't really have the ability to bring in cranes and heavier equipment due to the location and such. So, while I think the scissor truss is the way I may have to reluctantly go, I was hoping to come up with something I think would look great, maybe with exposed wood, as rustic as possible.


Thank in advance!

 

[Bud9051]

Couldn't follow your description sufficiently to comment on which option is best, but meeting modern codes and best practices for insulation and ventilation with a vaulted roof can be a challenge. A scissor truss with a raised heel might be an option.

Bud

 

[Nealtw]

Rafter ties are ceiling joist and have to be in the bottom third of the rafter so they are not part of your picture.

With out crane availability you will have to come up with some ingenious lifting methods that will be just as important as what you build.

My first thought was for vaulted trusses and bonus room trusses for the loft.
You could also consider the bonus room trusses with the first one being the 2 or 3 ply girder truss that would support the beam for the great room. That would be a question for the truss engineers.



Timber framing would be an option but then you are looking at more heavy lifts and likely more costly. It starts with ordering special beams with out heart wood. It is not off the shelf stuff.

 

[Nealtw]

This style of vaulted truss gives you the raised heel cut that @Bud9051 mentioned , the pitch is the same in and out and would be easy for the truss company to make bonus room trusses to match .
And you can see the worker installing the best venting system i have ever seen.

 

[P C D]

Just use a bigger ridge beam to support the longer span, and use 2x10 or 2x12 rafters to accomodate the insulation requirements. The residential code offers a ventless design for these types of roofs involving rigid insulation in direct contact with the underside of the roof deck.

 

[3onthetree]

Is this an addition or a piece of the whole house build? Location? DIY by yourself or with helpers? How is the remaining house roof framed? Skylights? Do you want a completely open vault or have framing visible? Maybe posting those plans would help visualize.

- Trusses will reduce your ceiling height if you don't raise your outer wall. Sounds like the loft needs to look out over the great room, is it connected to the 2nd floor main house or just within this 1.5 story?

- Ridge beam can be designed without rafter ties. Beams can be sistered once raised. Glulams can be stained. Wouldn't a post land on the wall entering the room?

- Timber frame is a whole nother monster, specialized and even more difficult to build. Big $$. You can always make a faux timber look.

 

[P C D]

A 22.5' ridge beam would need to be a glulam weighing between 500 and 1000 pounds, depending on your design snow load. Two people can raise a half-ton beam without braking a sweat in a couple of hours with a couple of wall jacks mounted on vertical doubled 2x4s, available in most rental places. The doubled 2x4s would need to be well supported on the top and bottom. As you crank each jacks's handle, the jack rides up the 2x4s along with whatever is mounted on them. Easy does it.

 

[Crafty42]

Couldn't follow your description sufficiently to comment on which option is best, but meeting modern codes and best practices for insulation and ventilation with a vaulted roof can be a challenge. A scissor truss with a raised heel might be an option.

Bud

Thanks! Was definitely considering the raised heel scissor. I'm just exploring all my options and see what others may have come up with.

Rafter ties are ceiling joist and have to be in the bottom third of the rafter so they are not part of your picture.

My first thought was for vaulted trusses and bonus room trusses for the loft.
You could also consider the bonus room trusses with the first one being the 2 or 3 ply girder truss that would support the beam for the great room. That would be a question for the truss engineers.

Timber framing would be an option but then you are looking at more heavy lifts and likely more costly. It starts with ordering special beams with out heart wood. It is not off the shelf stuff.

I thought rafter ties could work, if they only needed to be every 8 feet instead of every rafter, but I wasn't sure. I'm sure there would be ways to make them decorative and non-intrusive if spaced out far enough.


The bonus room trusses bring up an interesting option that could play into my house plans, which I didn't go into all the full details on.


I basically eliminate timber framing awhile back, but was almost wondering if it could work as a hybrid, timber framed roof trusses and stick framed rest. It's have to be timber framed down to the ground under the trusses, I'm sure.

This style of vaulted truss gives you the raised heel cut that @Bud9051 mentioned , the pitch is the same in and out and would be easy for the truss company to make bonus room trusses to match .
And you can see the worker installing the best venting system i have ever seen.

Yes. I am heavily considering the vaulted parallel chord. That was option 2. Not sure I will go with the venting you are showing. I'm slightly aware of it, but would depend on the added costs. I feel like that option would cause the interior air to get a little stale though, especially times when windows or doors aren't opened much.

Just use a bigger ridge beam to support the longer span, and use 2x10 or 2x12 rafters to accomodate the insulation requirements. The residential code offers a ventless design for these types of roofs involving rigid insulation in direct contact with the underside of the roof deck.

I don't want a support post running down the middle of the house that would be needed to support the ridge beam. Sorry, I know my original post was long and that point might have been missed.

 

[Crafty42]

Is this an addition or a piece of the whole house build? Location? DIY by yourself or with helpers? How is the remaining house roof framed? Skylights? Do you want a completely open vault or have framing visible? Maybe posting those plans would help visualize.

- Trusses will reduce your ceiling height if you don't raise your outer wall. Sounds like the loft needs to look out over the great room, is it connected to the 2nd floor main house or just within this 1.5 story?

- Ridge beam can be designed without rafter ties. Beams can be sistered once raised. Glulams can be stained. Wouldn't a post land on the wall entering the room?

- Timber frame is a whole nother monster, specialized and even more difficult to build. Big $$. You can always make a faux timber look.

I could possibly post the plans later. I'm away from home. I'll do my best to describe it. Completely new build for everything, with helpers at times, but a good bit will be after work on my own. I'm in SW Pennsylvania. 30 psf snow load if you needed to know. I haven't worked out the windows and door locations exactly and while I do like the idea of skylights, I'm not a fan of them when they start to leak, and they most certainly will someday.


Looking at the house, the Great Room would be 22'8" wide and runs about 30' back where it then increases in width on both sides by 8'. That then runs another 26' and comprises of the main floor. The second floor (starting opposite the Great Room) is then 22'8" wide and runs 34'. The last bit being a loft area overlooking the great room with bedroom and bath.


The current plans have the roof as a 12/12 pitch running the entire length ~22'x56', with ~38' shed dormers coming out both sides with a 4/12 pitch over them and over the 8' 1st floor areas. There is also an 8' wrap around covered porch that would tie into those as well. Actually, here's the link to the original plans:


Farmhouse



It won't give you all the details there, but you can see what I'm generally working with and towards. As a reminder, I've moved the chimney to the Great Room Exterior wall, and I plan to shorten the loft back 4' and am re-arranging a LOT of things. But overall the footprint and shell isn't changing that much. I will be closing in the grilling porch and making that into a mud room.



It's hard to say what I really want, which is why I've been trying to reach out to architects to help me with getting a vision to work towards, but that hasn't worked out yet. I like open framing, but at what cost is it going to be? I'm exploring my options while reluctantly realizing I'll have to keep it simple and maybe dress it up with the faux timber as you mentioned.


Thanks, and sorry, I know I can get a bit wordy.

 

[Nealtw]

This the venting I mentioned, anything else is second best or worse.

 

[Yodaman]

Per the OP's comment regarding stale air, almost seems like he is confusing roof deck venting (as shown above) with room air ventilation.

 

[3onthetree]

I don't want a support post running down the middle of the house that would be needed to support the ridge beam.

I'd probably shy away from trusses. The opening of the loft area looking out over the great room will be reduced. Also, if you want vaulted ceilings with exposed framework upstairs, you don't have a lot of depth to fit a truss and still give a dynamic looking interior slope. The old fireplace was a good stopping point for the ridge beam, but you can still support the end either at the edge of the loft or loft back wall depending on ridge length, and the post does not have to be right under the ridge all the way down. You could split the 22'-8" into thirds with columns.

 

[Crafty42]

Per the OP's comment regarding stale air, almost seems like he is confusing roof deck venting (as shown above) with room air ventilation.

It's likely. I'm no home builder or understand how everything works. I know I've heard that newer houses are often built more air tight than older ones. I blame all the increase in codes and requirements. Thus causing not much turnover in whole house ventilation and not letting some fresh air in.


My thought was with that system, the air coming in at the eaves will go straight up and back outside, so no turnover in the house. But I'm not exactly sure I have it right.

 

[Crafty42]

I'd probably shy away from trusses. The opening of the loft area looking out over the great room will be reduced. Also, if you want vaulted ceilings with exposed framework upstairs, you don't have a lot of depth to fit a truss and still give a dynamic looking interior slope. The old fireplace was a good stopping point for the ridge beam, but you can still support the end either at the edge of the loft or loft back wall depending on ridge length, and the post does not have to be right under the ridge all the way down. You could split the 22'-8" into thirds with columns.

Thank you for the reply and drawings to help show. You bring a lot to consider. My thoughts are...I'm a single guy and the 2nd floor was going to be for guests or resale value. The loft is nice, but I'm not going to use it, but I certainly don't want to detract from it. With moving the loft back 4' and keeping the dormers the same length might help (a little) to not restrict the loft view into the great room. I'm trying to convince myself to go with trusses for the ease of construction, but I am torn because I'd rather go with rafters and ridge beam. It helps to tell myself I don't want columns running down through the middle of the house. But these are just initial thoughts and I need to soak this in. You have given me a few things to consider!

 

[3onthetree]

With moving the loft back 4' and keeping the dormers the same length might help (a little) to not restrict the loft view into the great room.

The end of the dormer is the edge of the loft. If you move the loft floor edge back 4' and keep the dormer end wall where it is, you'll have an odd 2-story-high 4' wide nook up high on both sides of your great room.

 

[Crafty42]

Also, if you want vaulted ceilings with exposed framework upstairs, you don't have a lot of depth to fit a truss and still give a dynamic looking interior slope. The old fireplace was a good stopping point for the ridge beam, but you can still support the end either at the edge of the loft or loft back wall depending on ridge length, and the post does not have to be right under the ridge all the way down. You could split the 22'-8" into thirds with columns.

So the plans as they provided them had vaulted ceilings above the loft and bedroom 3, but not above bed 2, which I wasn't sure how that was going to go. My thought is that I don't need the ridge line to be even the entire length of the house, so I'm thinking about raising the ridge height above the second floor to allow some vaulting over everything. The Great Room ridge will be lower than the main house ridge. At least this is what I have been recently considering.


If I split the 22'8" into thirds using headers/beams and columns, this only increases the number of posts.


I should note there is a full basement under the house as well, so those posts need to travel down into the slab, right?

 

[Crafty42]

The end of the dormer is the edge of the loft. If you move the loft floor edge back 4' and keep the dormer end wall where it is, you'll have an odd 2-story-high 4' wide nook up high on both sides of your great room.

The reason is that I wanted to increase the great room and that on the one side I am putting a staircase up to the loft. I didn't like where the current one is and it interfered with a lot of other things I was doing. I'm picturing the stair layout to look like the attached. Only in that it is wide open on the downstairs side.

 

[Crafty42]

The end of the dormer is the edge of the loft. If you move the loft floor edge back 4' and keep the dormer end wall where it is, you'll have an odd 2-story-high 4' wide nook up high on both sides of your great room.

You do have me wondering what that other side will look like with a 4' wide, 2-story nook. I'll have to figure out something to use it for.

 

[Nealtw]

Thank you for the reply and drawings to help show. You bring a lot to consider. My thoughts are...I'm a single guy and the 2nd floor was going to be for guests or resale value. The loft is nice, but I'm not going to use it, but I certainly don't want to detract from it. With moving the loft back 4' and keeping the dormers the same length might help (a little) to not restrict the loft view into the great room. I'm trying to convince myself to go with trusses for the ease of construction, but I am torn because I'd rather go with rafters and ridge beam. It helps to tell myself I don't want columns running down through the middle of the house. But these are just initial thoughts and I need to soak this in. You have given me a few things to consider!

I looked at the house from the back and see it this way with 3 different trusses .


The floor of the loft will be held up with interior walls or beams.
You would have the scissor truss in the front, a 4/12 truss with a peak added to the top.

And 8 ft jacks around the front and sides.

 

[Crafty42]

I looked at the house from the back and see it this way with 3 different trusses .


The floor of the loft will be held up with interior walls or beams.
You would have the scissor truss in the front, a 4/12 truss with a peak added to the top.

And 8 ft jacks around the front and sides.

Interesting. I was assuming the 4/12, 8' roofing would all be done by rafters that would rest on the second floor joists and run out to a header. I wasn't thinking trusses for that area. The 1st floor ceiling height is 9' and the plans calls for 16.5" floor trusses. The the rafters would run from 10' 4.5" out to a header that is 8' from FF. That's a 3.5/12 slope (I think) and if I could tweak that slightly.


The rest is definitely something to consider.


I'm still working it out, but he plan was to try to eliminate all the pitch changes that the original plans call for. Make it one pitch over second floor, one over great room, and something similar to second floor over the sides etc. The original plans has a 12/12 going to a 4/12 then 2nd floor wall down to a 12/12 changing to a 4/12 again....



Can you give me some insight into your sig, since I might have scissor trusses out to a gable?