I want to add a dormer to bungalow/cape cod style house with an 8/12 pitch roof. My problem is that the first floor ceiling joist run perpendicular to the rafters. The house is also ballon framed with about 14″ of first floor wall studs rising above the level of the 2nd floor. The rafters sit on that plate ( first floor ceiling joist 14″ lower) and are not tied into each other as in conventional framing. No triangulation here. I want to build two 8 ft dormers or one 18 ft. The house is 34 feet wide along the gable ends. How should I approach this or should I give up on the dormer(s).
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It can be done but you should have an experienced framing contractor on site or supervising. There are so many details and potential things to watch for that it would be unsafe to get what you need here in text.
Thank you. I do have a great deal of building experience. Sometimes it is helpful to hear what your peers would do. Experienced framing contractors in my area of Cleveland, Ohio only want to talk about new constructioin and not remodeling jobs. You get unique situations sometimes and there are several solutions. I am trying to decide the best approach by discussion of the options and opinions. What is yours? What is your major concern or where would you start? Thank yoiu for the reply and your time. William
My first concern, regardless of the direction of the lower ceiling/floor joists, is that by interrupting the existing roof framing, you most likely need a structural ridge beam. By your mention of triangulation, I have to presume that you have some idea of the loads and stresses going on. Since you don't mention collar ties, and since the flor joists are clearly not acting as such, it is possible that you already have a structural ridge. That would be defined as a beam capable of supporting half the loading, live and dead, on the entire roof surface.Excellence is its own reward!
You are correct. Excellence is its own reward but the enemy of good. You have to know when it is excellent enough ( in building of course). No structural ridge. It has a 1x8! Collar or rafter ties are in place. They are 2x6 on every rafter at 8ft from the floor. Originally placed in a previous remodel to act as ceiling joist for the second floor rooms. They of course are not ideally located in regard to adding strength to the roof system (60" from ridge). There are several collar ties above them on every 4th rafter that appear to be original. The roof has a slight belly that is lowest in the middle. Probably about 1.5 inches over 42ft. They also at some earlier date added skylights (now removed) with inadequate framing details around them. I was thinking of removing the necessary "collar tie/ceiling joist" placing new ones that extend from the roof rafter on one side to the top plate on the dormer face wall. Build my face wall on a glulam or LVL from load bearing point to another. Build the side walls on another LVL (perpendicular to the floor joist) again to set on load bearing points. It has been suggested to me to gusset the rafter tails that remain in front of the dormer and maybe even ties them into the knee wall. A lot I know but as you said there is a much for text to cover. Double rafters on either side of course. Shed roof about 4/12. It was also suggested to gusset the roof ridge on both rafter sides to gain additional strength. Any thoughts so far. Thanks. William
I ain't picturing all the detail you relate but I'll admit that I didn't try too hard after you said that you now have a failing ridge beam.
What you have now is proven inadequate because the direction of framing demands a structural ridge, IMO. You are also right that the collarties are less than satisfactory. As a general rule, to do the job demanded of them, they shpould be no more than a third of the way up the rafter. Sounds like they are more than halfway up. The structure as it exists is in failure. Then you propose openning a large hole in it and making it worse.
Please don't take this as personal criticism - just trying to help and refer back to my first disclaimer post.
But what you are proposing is nothing more than putting band aids on a broken leg. If you will get in there and slide or assemble a ridge beam in under the existing one and jack it up to tension loading (you'll need am engineers visit to help plan this all out) then you'll have something worth having. It probably won't cost much more than all the rinky dink patches you now propose and may be less than the total of all the repairs you will keep making over the next thirty years.
I did this with an assembly of four 18" x 32' LVLs in the attic of a honkin' big old house. It took a crew of three two days to install. We had an end gable wall vent to slide the material in through when it was delivered with a boom.
Do it right the first time and feel the glow of satisfaction! You'll be happier.2500 and counting...
It's possible to have quality AND quantity!
Excellence is its own reward!
Thanks. I actually stopped a work in progress when I got involved. They were planing to just cut a large hole in the roof then jack it up as the new dormer roof! ? in order to save the new shingles. WOW! I mentioned that I was in the planing stages and wondering what other people had to say about the project. In regard to the structural ridge. This is always the best approach in my estimation. I have an engineer on his way. I may just abandon the whole project as too costly. Apparently, the argument I get is the house is paid off and this is the resurrection. The house I also discovered has a crack in the garage wall that I determined needs some type of piers or new foundation. Hey, any thoughts or experience with helical anchor type piers or Chance helical piers to shore up a sinking foundation. The Ram Jack company is the local foundation repair company. They seemed to used extensively in this area commercially. The entire area with new mall and housing projects has had a large change in drainage characteristics and everywhere cracks and sinking foundations are cropping up. Plus are local drought. So much for progress. No developer or building department puts this in there development cost. the poor homeowner foots this bill two years later. Thank for letting me run all these things buy you. All you suggestions are appreciated. I work solo and it has been great to have your expert opinion. It seems you have the hands on experience. William.
WOW! is right!
It sounds like they have someone paying attention. Now if the owner will pay as much attention to you as you are paying to the house...
Jeff Buch has a thread going about the magistrate arbitration bewcause of a job where he advised the owner who disregarded his advice and is now having to sue for dollars he earned but the owner is blaming him for doing what they demanded.
So go careful and do it right or not at all..
Excellence is its own reward!
Got that right!
And I'd suggest ...in that area....dropping a line to Pete Draganic, Big Cal Stewart, or John Svenson(aka Svenny/JRS).....to see if they've deal with anything similar...as they'd be somewhat close to the area. Jeff.......Sometimes on the toll road of life.....a handful of change is good.......
Thank you. No job is too important not to take the time to do it right. My father had that on a plaque inside his employee's trucks. What is your take on the helical anchors (hydraulically deep driven steel piers) for foundation sinking and cracking.. Is this junk science. Have you seen it used? I need imput on this. Thank you. Liam.
I had passed on that because I don't know a thing about them. I only seem to know everything but I'm really like the Wizard of Oz, behind the little curtain...
;-)
Since this thread is titled Dormers, I'll bet that a lot of foundation and soils guys who know the answeer aren't even reading it. Try a search and a new thread to get to them. .
Excellence is its own reward!