Al and Robins 20x30 1 1/2 near Lake Eufaula, OK

[MWAndrus]

To me, that roof looks like it needs to be built with a ridge beam and columns, or it needs rafter and collar ties. The force from the roof is going to push the walls outwards. It would be worse in the second story because of the hinge point where the wall meets the second floor.

[Don_P]

Yup, that is correct. Unless there is a level ceiling in the lower third of roof height this would need to have a properly sized ridge beam on columns. I think you have trouble w/ the gable wall heights as well.

Is there a reason not to go to a lower pitch, say a 4/12, above and get more headroom? Things don't stop at 12/12 either, you can raise the ridge by making that section steeper if needed.

[ajbremer]

Thanks Don_P and MWAndrus,

A framer came around today and we talked for a couple hours about my build and how I've been doing.
Some of the things he pointed out to me were:

1) My braces were not high enough, he said I should have them right to the top.

2) Don't use the saws-all to cut out the windows that are covered by sheathing, poke
the nails through from the inside, pop the line around them, and then use the circular
saw from the outside. The saws-all is messy and time consuming.

3) He told me to get a nail gun, period! (I've done the whole thing by hand so far)

4) For rafter sizes, he said around here in Oklahoma most use 2x8's at 16 o/c or 2x10's at 24

5) Most use 7/16 for sheathing (I did my first long wall with 5/8). When he saw that I used
the 5/8 thick stuff for the first long wall he said that it would cause my door jam to not be
positioned properly for the inside dry wall/trim.

6) I can use the 32 foot long 2x8 as the ridge board, just add a 2x4 under it.

7) It's good to have a gap under the ridge board where rafters are a little bit lower so that
the drywall can meet together up there.

8 ) Nail top plates where studs are under them because long nails sticking out under there can
cause trouble with drills, saws, and wires.

9) When he does stair stringers, he goes with 7 1/4" rise and 10" run...I think that's what he said.

10) In regards to my loft, he said I should buy rim-board and use i-joist hangers and then
nail and lag screw it to studs (at places where the i-joists don't go).

11) He called the side wall where my pitch change is going to be a half-gable, I've heard it
was called a cheek-wall.

12) I showed him some pics of the recent build examples I posted above where the pitch
went from 10.5:12 to 6:12. One of the pics above showed the sheathing an inside shot
of the side wall (half-gable/cheek) without studs, he mentioned that there should have
been studs there.

13) His opinion about me chopping my loft walls down to the 8 foot height and platform
it from there was that I could do that but that it would be strong enough if I build the
almost 5 foot wall on top of the already 10 foot wall also, either way. The gable end
would support one end, the cheek wall studs and the two pitch change studs against each
other, and sheathing along with the collar ties would support the other end.

14) He had an extendable level and he checked each one of my wall corners and they turned out
pretty good. I think the worst case was one was out 3/8".

He mentioned a lot of other things but I guess those were the headliners. The most exciting
thing was that he said he would come out with his crew of a few guys and put up my whole
roof in one day...with me helping so that I can be apart of it all (for a really good price too).

So what I have left to do is string line the walls straight (which I already did but I'll do it
again to be sure all is well), finish sheathing, finish all interior walls, put the i-joists in,
and then the loft sub-floor. I'll leave out the catwalk until the roof is on.

[Don_P]

Wow

Well, he's told you what you want to hear. I don't agree with him.
I'd like to walk you through what I see as the responsibilities here. As the general contractor and designer, you have hired labor. In the event of an undesired outcome this crew was working under your direction. In other words, you have not hired competent design you have hired man who swings hammer, the design and anything that transpires as a result of that design is still your responsibility.

On a job directed by an owner builder this is where I, as a man who swings hammer, would stop work, and have.

The correct next step is to bring in a structural engineer.

[ajbremer]

Sunday Afternoon - February 26th, 2012 Oklahoma

Thanks for the response Don_P.

I am glad that the framer guy came over, he did tell me things that made sense and then again
he told me other things where I need to listen to other peoples suggestions also.

I believe the best thing for me to do at this point is to build it the way it was originally planned
by John, a 12:12 pitch roof all the way - like most have done here with the 20 x 30 plan. I would
have liked to have that fancy pitch change that would cause more head room but I didn't start
correctly for that type of build and it's best to stick with the original design.

I would like to say thank you once again to the Don's and John's of this site who keep us safe
if we'll listen to them. Thank you countryplans...I'm go'in back outside to put up more 4x8 sheets!

[MountainDon]

What happened to the idea of those well engineered trusses we all saw a while back? Those would make a roof with unparalleled strength, as well as lots of room for insulation and good headroom.   

[ajbremer]

Ya Don, thanks for reminding me of those trusses. I know money shouldn't matter when
you talk about a good roof - that's money well spent.

I've got a ways to go before it's roof time and hopefully I'll be able to get up the $2,700 for those
trusses at that time. Here are their pics again:

[UK4X4]

Just to make you feel better- my roof trusses on a 26x36 were quoted at just under 5K usd....scissor for the main with 4 dormers

The dormers would need standard framing....so say 6K before being sheathed

[ajbremer]

Sunday Night - February 26th, 2012 Mid-Oklahoma

Thanks UK4X4,

Yes, your trusses sure were a lot higher priced than the ones quoted for me.

Thank you again UK4X4. By the way, I looked for your build on here and found this one:
http://countryplans.com/smf/index.php?topic=9588.0#top. Is that your main build?

[astidham]

Al, since you have the build blueprint, you could build your own.
join them together with plywood  .

[ajbremer]

Sunday Night - February 26th, 2012 Mid-Oklahoma

Thanks astidham, it's great to hear from you again.

I worked most of the day putting more sheathing on. A neighbor came over with his nail gun, a huge
box of nails, and a long air hose. He wanted me to borrow it as long as I need it. He told me before
that he would lend it to me but I just kept on hammering.

He went on to demonstrate how to use it, I had never fired one before. Wow, I wish I would have gotten
one a long time ago. At first it was driving the nails way into the 7/16 sheathing so I turned down the
pressure on my air compressor and it seemed to do well after that, they went just barely more
than flush. I missed a stud one time and it went right through and bounced of the far wall - wow, their powerful.

As far as my roof goes, I don't see a problem with using the ridge board and rafter method
for my build, it is much less expensive than the trusses and I'll be sure to use collar and rafter
ties. It's not as strong as trusses I know but it's strong enough and I can put enough
insulation in it to be comfortable here in mid-Oklahoma. I love the idea of the site built
trusses that are included in the plans but the ridge board method would take a lot less time for
me to get done (especially if I have a framer come and do it while I help).

[MountainDon]

1. Don't overdrive nails. If they are overdriven basically they don't count; the connection strength is greatly reduced.

2. It's not the strength of the trusses vs strength of rafters that is the concern. Rafters and ridge boards can carry the same loads as a certified engineered truss when the rafter and ridge combination is properly sized and constructed as illustrated in the IRC. It's the area of each loft floor where you will not have rafter ties if you use rafters and ridge board that is the concern. The tops of the side walls in the loft areas will have horizontal outward forces that can be quite significant in a 20 ft wide building.

A rafter and ridge board roof places one half the roof load on each side wall; dead load (materials) plus live load (snow, rain, wind, ... Wind load on a 12/12 pitch can be as significant as a once in a hundred year snowfall).  With a 12/12 pitch half of the load on each side wall will be more or less straight down and the other half will be pushing sideways on the tops of the side walls. That could easily amount to many thousands of pounds of force trying to push the wall tops apart. We have tried to make this point seem relevant and important several times right from the inception of this project. I believe I am correct when I state that anyone who has built a plan such as this in a location that faithfully applies the IRC, would have had to use a ridge beam or certified engineered trusses when the project included loft kneewalls as you have. This is not just because some locations want to collect fees; it is because ridge beams and certified engineered trusses do not transfer horizontal loads to the side walls. Stud wall tops like the kneewalls are not designed to carry horizontal loads of the magnitude that a rafter and ridge board roof can generate. The taller the kneewall, the worse it gets.

Don_P's idea of cutting off the kneewall studs and placing the floor joists on the top of the resulting wall has advantages. The platformed framed walls that would be added would then have rafter ties on the tops of those new wall sections at the loft. Or at the very worst the rafter tie could be moved upwards slightly (no more than a third) to increase headroom. As long as the rafter tie would be located in the lower third of the rafter and ridge board triangle the rafter tie will effectively restrain any outward forces. Note that when rafter ties are moved upwards the rafters themselves may need to be sized upwards.

In closing, read the first part of my signature line.

[duncanshannon]

Al-

I think you are headed in the right direction by simplfying your build wherever you can.   I'm in a similar boat as you... never done this stuff before.  I'm planning (some day) on building the 20x34 1 1/2 story or so... somewhat because it seems about as simple as you can get.

From working on my home, i've learned that keeping it simple is a really good thing in terms of keeping cost and time down.  Its amazing how it all starts to add up.

I'd go for the same roof pitch for the entire roof.

Sounds like you need to re-read the ridge board vs ridge beam stuff from the Don's too.  Or just go get some mfg. trusses and keep it simple!

way to go by the way.... keeping at it and making progress! excellent work!

[Don_P]

This is not a huge deal to do right, that just isn't the right way to do it. The split pitch is quite possible as is the original design. The build process is a very short portion of the life of the house, get what you want. Look at the headroom on the stairs before you scratch the design, I think that decision has some ripples.

I don't think you are going to build a safe or compliant steep pitched roof section in ridgeboard and rafter ties or site built trusses.  With a ridgebeam or engineered trusses I think you can build a very strong roof.

Changing the walls is not a huge project. Smaller trusses over a second floor would be cheaper than the larger trusses over the loft, they can be scissors to give a bit more headroom and allow the sidewall to be a bit shorter.

The catwalk cannot join to just I joists, they are not rated for that type of point loading. The joists at each end of the catwalk need to be LVL(s). I would go ahead and install the catwalk to make moving around up there safer and easier while doing the roof.

[UK4X4]

"Thank you again UK4X4. By the way, I looked for your build on here and found this one:
http://countryplans.com/smf/index.php?topic=9588.0#top. Is that your main build?"

sadly yes ---not a nail hammered in anger yet !

just updated it and will add the revised plans shortly, with some info on the helical piles etc

[Alan Gage]

RE: the increased cost of trusses:

Looking back on my build I can't think of one area where I regret spending too much time or money. I can find some areas where I wish I'd spent more though.

I still spend my dollars carefully and all those upgrades can and do add up in the end but this is your house and you're building it yourself. The farther along you get in the build the more pride you'll have in it. You're going to (hopefully) be there a long time, you don't want to be constantly looking back wishing you'd done something different.

Alan

[UK4X4]

Truses- my reasons

High snow load
Speed of install  - labor time
Engineered- no probs with the permit office
Engineered- no rooky errors causing a cave in !

yes there's a cost increase- but I only want to build once........plus if I have to pay an engineer to check my design by the time I've added that to the cost of materials - it would be a close race on the costs

[Bob S.]

I have not started my build, but I have been planing it for several years. When I priced the # 2 2X12's and the material for the coller ties and the hardwaer and offset it with the price of trusses there was only about $400 deference. When I build I will use trusses.

[CjAl]

he told you to leave the rafters cut with a gap below the ridge board? doesn't that right there nullify any further info he gave you since everything I have heard is to have the gap at the top otherwise the rafters will split.


unless my math is wrong, couldn't he use three 2X12's nailed together as a ridge beam with a support in the center? run tripple 2x6's up the full length of the gable end walls and one 6x6 up from the floor in the middle of the house (probably right where the roof pitch changes anyways) and run the tripple 2x12's across the top of them and cut common rafters to sit on them?  You can go back later and wrap them with a thinner cedar or something if you want a "pretty" beam at a fraction of the cost. It's what I plan on doing. I don't have my figures in front of me as I'm on the road sitting in my truck but mine is 32" and if I remember corretcly the load calculator came up about a foot short for tripple's being okay for my application. should be just right for him then.

[metolent]

That's close to what I did CjAl - well, except that instead of building up the ridge beam and posts, I used a 6x16 glulam for the ridge beam, and solid 6x6s for the 3 posts holding them up - picture below.  He would have to probably change the wall structures to get the posts in, but that's not a big deal.  The thing I would be more concerned about would be transferring those point loads to the ground given the steel post foundation - I'd have to do some math ...

Seems like the easiest thing to do would be to go to engineered trusses given where things are now.  For me, I wanted the open ceilings, so a ridge beam made the most sense, but then I designed the foundation and walls for it as well from the get-go.  If you really want that upper dormer, I wouldn't give up on it now because 6 months after you're build is complete you may regret not spending the time/money to get it the way you really want it.... 

[ellbaker]

So what should you do if you wished this thread was active a year ago?  My framer added a shed dormer after I asked for one during the build. My dormer is a 4:12 pitch.  I do not have rafter ties in the dormer section.  Framer said it was no problem, he does it all of the time.  Any way to fix this now?  My ceiling is finished now.

[Don_P]

Dangling rafter plumb cuts as well.
Tie it with a level ceiling would be one way.
At this point I would monitor it. Pull a tight string from corner to corner along the top plate of the dormer wall. Is the wall straight or bowing? Whatever is there is likely the same at the ridge. This is now reaction, you've realized too late, hoping to have Al's done pro-actively.
If there is a wall under the ridge it will act the same as having a beam under it... Al has this but look down, the floor was likely not designed for the load at midspan. I have this going on in my house, no ties, ridgeboard construction, roof sagging and wall bowing. There is a cross wall and an in line wall under the ridge that took the load as the roof sagged, it held,  but the floor now has a permanent sag from supporting the roof, the wall leans out, the ridge has a sag. If that inadvertant wall had not been there I'm pretty sure my roof would have snapped thru in a freak snow. We had my naive design load path and mother nature showed the actual load path. My floor is dimensional 2x10's at 14', this is I joists at 20', my ridge is 2x12 with no span between support greater then 12', this is 2x8. I am well beyond code but so far within the ultimate strength of the material. I've debated popping the top and trying again several times, that's working behind the ball, reaction. I've simply had about a hundred attempts at getting it right since. Hopefully we can save Al a few practice tries.

Just playing with it, This could be trusses, the main pitch is 12/12 the upper is 4/12 on 7'6" sidewalls. I "fully dressed" the dormer end just to show some other options.

[ajbremer]

Wednesday Afternoon - February 29th, 2012 Mid-Oklahoma

Thank you everyone, there is so much information going on in these last few posts - I am totally greatful to ya all.

I've definitely decided to NOT go with a ridge board. I like the idea of a ridge BEAM and I think they look real nice but I'm trying to get trusses at this point. I'm anciously awaiting a quote from a different truss builder locally and I'll share that with you all as soon as possible. I've been on the look out for the truss quote all thru the day today. I like the other trusses that were quoted for me in the past but I would like to see this 'second opinion/method'.

Don_P, thank you for taking the time to do that drawing. I understand a lot more about roofs in these last few days with all this great information.

Now about my floor taking a load at mid-span for a ridge beam column (if I went that direction). I DO have a girder that's held up by 5 piers running down the exact middle 30 foot length of my build. I dug really deep holes there and the steel is braced really good, the 2x12's are also held up by the angle-iron. BUT, I'm really leaning toward trusses at this point in order to keep with the change pitch decision.

I know I keep changing my mind about what type of roof to do but I'm learning and I'm glad I can change my mind and that it's not done the wrong way.

I had the truss guy quote for 12:12 pitch for 15' and the other 15' will be 6:12. I'm awaiting the quote as I type right now and hopefully within a couple hours I will share it with you all. Again, I appreciate countryplans!

[ajbremer]

Wednesday Night - February 29th, 2012 Mid-Oklahoma

I got another truss quote today. I told the truss builder that at the half way point (the
15 foot point), that's where one pitch will change to another. I can give you all the facts
in text right here but I'll post a picture and the two jpg files that the truss company
emailed me. Just to let you know, I emailed the truss builder my plan information and
also a 3D rendering of the 2nd floor so he knows what kind of house these trusses are for.

One question I have about these two different pitched trusses coming together is, will one
truss be nailed up against another truss at the point of change or would there be some kind
of blocking between them?

Now, the biggest thing about these trusses is that they are all 2x4's - that sounds weak...or is
it just me? They are rated for my build and the truss builder said that they'll be stamped by an
engineer. Please let me know what you think.

Here:



And here are the actual jpg files of the quote, one is the 12:12 pitch and the other
is the 6:12 pitch:

[MountainDon]

You have two solutions to the same problem. These are just different from the first. These are more typical of what I envision when I see the word truss. These are commonly made with 2x4 lumber. It's a special grade you will not find in HD or Lowe's. It is not the size of the lumber that matters, it is the engineering that goes into the creation of the individual components that make up the whole. The different configuration compared to the first truss from a while back means the interior will look different.

Less lumber and of smaller sizes results in a lower cost.

Depending on how much insulation you would like out where the truss rests on the wall, you may want to ask this second company what it would cost to have raised heel trusses made. There are some extra pieces and that lifts the truss up off the wall plates to give more attic insulation space. IMO, it is worth the extra cost. Whatever insulation amount you figure is good today is probably not what you will wish you had ten years from now. That's my opinion, as heating and especially cooling costs will do nothing but continue to increase.

I did not take the time to see what the actual headroom would be under the truss centerline over any loft floors.