Roof problem - need advice

[themoneypit]

Hello. I can see by reading the topics here that you all are pros. We have a problem and don't know what to do and I'm hoping some of you can advise us.

I have a 120-year-old modest one-story Queen Anne in rural Missouri. We've spent about two years undoing "remuddling" and trying to restore it. I am not a carpenter but I know good carpentry - my dad was a carpenter and a contractor with a good reputation for roof framing that the older guys still talk about - unfortunately, he died young in 1981. My brother has followed in his footsteps with the same skill and reputation and is now in the process of adding a room onto the back of my house.

But we have a problem. The house has a hip roof with gables out the front and sides. Please excuse my terminology - I can't speak your carpentry language. The plan was to extend the room out the back with a gabled roof joining the hip roof. The pitch of the hip roof is 9/12, and the pitch on the addition is 9/12, or is supposed to be.

I know if he had just set out to stick-build it, it would have worked. But my best friend, also co-owner of the local lumberyard, came by and talked us into using trusses for the roof since we were planning to put attic storage in it. My brother has not worked with trussed roofs in a situation such as ours, so we got the roof pitches and told her what we wanted and she assured us they could build the trusses to fit our purpose. So they were built, delivered, and placed yesterday and joined to the roof and here lies the problem.

The lines of the trussed part are not parallel with the lines of the hip roof - they appear to be at a different angle, and it looks horrible. One of my pet peeves has always been add-ons with roof pitches that don't match the existing roof - same with my brother. He did everything right. Even the people from the lumberyard (they also build pole barns) said so. But it is not matching up.

I am going to try to attach a picture so you can see what I mean - the lines of the trussed roof are in red. The gray is where it should be. You can see the lines of the trussed roof aren't parallel with the lines of the hip roof.

What is wrong here? Can it be fixed? What would you do? I hope you'll please advise us here - we are stumped. Half of the roof is sheathed and they are going to take it back off tomorrow. Please feel free to use carpentry jargon - I am going to have my brother read this. He'll understand it even if I don't.

Thanks so much in advance!!!

Sandy[/img]

[giddonah]

so, the addition roof doesn't meet up with the original roof? You have a gap there? If so, then you can frame it out and put in some plywood to fill in the gap. I trust that you're re-roofing that side of the house?

[grumpydasmurf]

so, the addition roof doesn't meet up with the original roof? You have a gap there? If so, then you can frame it out and put in some plywood to fill in the gap. I trust that you're re-roofing that side of the house?Ditto. No reason to remove the sheathing and trusses, just frame the gap and sheath it.

[themoneypit]

No, giddonah, that's not the problem. The problem is that the valley where new roof meets old is not parallel with the line of the old roof. It is off at the top by about 9".

[themoneypit]

Sorry, Grumpy, didn't see you. Thanks to both of you for responding. I don't think I made myself very clear. I hope it's clearer now. The sheathing is already on. The valley and the line of the old roof are not parallel. But I also think we figured out the problem.

Sandy

[giddonah]

I see it now. The problem doesn't have a neat fix. If you want the valley to be parallel to the hip ridges (not sure what they are called), then you'll have to raise the end of the new roof a few inches and lengthen it. Then, the new roof's ridge will slope down from the junction to the old roof towards the new gable end. I'm afraid the only solution to this might have been to see this coming before the roof was designed. Unless someone else can come up with something, I think you're stuck.

[Joe Carola]

Sandy,

The problem is that the pitch of the additon is not a 9/12 like the house so therefore the valleys aren't parallel with each other and since it is done already and sheathed you'll either have to live with it or add rafters on top of the sheathing at 9/12 to raise the ridge.

The rafters would go from nothing on the bottom to a 9/12 plumbcut at the top with a new ridge sitting on top of the first one.

Is it worth doing that, it's your call.

I copied your drawing and drew in blue what would have to be done if it helps.

Joe Carola

[themoneypit]

Thank you, Joe. I just got home from work and my brother has started doing exactly what you describe and it appears to be working. The strange thing - and the one we can't figure out - is that the pitch of the existing roof on the house is 9/12 and the pitch on the new trusses for the addition are also 9/12, and this has been confirmed in many places. The construction people from the lumberyard that manufactured the trusses also came out and are as baffled as the rest of us.

One of my pet peeves has always been to see room additions with roofs with different pitches than the rest of the house - rooflines that don't match or parallel. And my brother was furious - he said his "name" and work is going into this project and he wants it to look right, like what you've drawn. What he's doing now will make it look right, but it's a darn shame that we ordered trusses for ease of installation and are having to rebuild them.

It's going to add to the cost and set us back a few days, but I figure in the long run that if we don't fix it, it will drive me crazy for as long as I own this house - and I plan to own it forever, as much work and money as I've put into it. And if my brother doesn't fix it he isn't going to be proud of the job. (And he knows how picky his big sister is.)

Murphy's law at work. I just don't understand what happened.

Sandy

P.S. Edited to add that only half the roof was sheathed and we are just going to take it off and add the wedge boards to the trusses.

[Joe Carola]

Thank you, Joe. I just got home from work and my brother has started doing exactly what you describe and it appears to be working. The strange thing - and the one we can't figure out - is that the pitch of the existing roof on the house is 9/12 and the pitch on the new trusses for the addition are also 9/12, and this has been confirmed in many places. The construction people from the lumberyard that manufactured the trusses also came out and are as baffled as the rest of us.

.

Sandy,

Since the pitches were confirmed at 9/12, assuming that your talking about the side of the roof that the two new valleys are sitting on was checked for a 9/12 pitch that means that the side of the roof the two valleys are not sitting on is not a 9/12 pitch. It's a differnt pitch which is very common around here anyway with Colonials with hip roofs. A lot of times the roof running from front to back is a 8/12 pitch and the side roofs are 12/12 pitch which gives you more room in thew attic.

If your hip roof on your existing house was the same pitch all the way around then your two valleys on new roof would be parallel to the existing hip. So what you have is a "Bastard Hip" or "Irregular Hip" Roof.

If you checked the other side of the roof that the two new valleys are not sitting on and it was a 9/12 then the side of the roof that the two new valleys are sitting on is steeper. According to your drawing I would say that the side your new valleys are sitting on was steeper..

Joe Carola

[giddonah]

And if my brother doesn't fix it he isn't going to be proud of the job. (And he knows how picky his big sister is.)

HOLY CRAP!!! If I didn't know better, I'd have to call my sister and ask her when she started the addition!!! :lol: :lol:

[themoneypit]

LOL, giddonah. Sounds like you know about these big sisters!

Joe, the drawing is not one of my house, it is just something I found that showed an add-on extending out from a hip roof that I used to illustrate the problem. My house faces north and the main ridge runs north and south. The front of the house has a gabled roof facing north but the back has the hip roof facing south. We are adding on out the back with a gabled roof over the addition. The pitch of all the roofs involved is 9/12 - the ones facing east and west off the main ridge, and also the back hip part. The trusses are 9/12, everything is true and square and symmetrical, but it's not working, and this is what has everybody so frazzled and confused because it should work. We are going to have to increase the pitch on the trussed roof to make it look right from the back (so we won't have to hang our heads in shame!).

I know we would not be having this problem if we'd not used the trusses, and that is what's so disappointing. I wanted the attic space above the new addition and the friend from the lumberyard said that the trusses could be engineered to accomodate this, and they were.

The house is 120 years old. I wonder if settling or something could be the problem. Also, we only checked the pitch in a few places. The house has a newly constructed roof (sheathing and roofing) on the whole thing, done before I bought it. Maybe it dips or something. The roof is straight and doesn't appear to change pitches, but maybe it does.

I guess it will all come out in the wash somehow. I sure would have liked to have the roof on by now, especially since we have five days of rain in the forecast. We already had one gully-washer that soaked the blown-in insulation on the back of the house and my new paint is stained on the inside and I am wondering if this whole mess will ever dry out. It makes me sad to know that in 120 years the 1 x 10s on the back of the house were never wet.

Alas, I didn't name myself "the money pit" here for nothing!

Sandy

[Sparks]

The first time I used trusses I was very disappointed with the quality control. Thinking back, I wish I had stick built as well.

[Joe Bartok]

moneypit: If all the pitches in the roof are equal and the lines of the ridges and eaves intercept at 90° in plan, the geometry guarantees that your Hip ridge and Valley trough will be parallel. To produce a deviation such as you describe a measurement would have to be seriously out of square or level. I think the most reasonable explanation is what Joe Carola suggests: One of the pitches is not 9÷12.
This leads me to wonder about your trusses. They may measure 9÷12 individually, but are they also producing a 9÷12 pitch on the adjacent or opposing roof plane as they step in sequence??? Just a thought.

[themoneypit]

Joe, yes, we agree with Joe Carola, too... but can't find the problem. We have been all over those three roof sides checking the pitch with a level and tape measure - it drops 18" in 2'. Same with the trusses. We just can't find the problem. My brother is adjusting the pitch on the trusses to give parallel lines when the addition and back of the house is roofed so it will look right.

This leads me to wonder about your trusses. They may measure 9÷12 individually, but are they also producing a 9÷12 pitch on the adjacent or opposing roof plane as they step in sequence??? Just a thought.

I don't really understand the question, but I'm going to print this out and give it to my brother. He probably will. I haven't seen him in a few days because we've been rained out and I've been away at work and have missed him when he's been here. It's so hard when I can't be here to "supervise."

It's going to work out, but I wish it hadn't been this much $$$ trouble.

Sandy

[Joe Bartok]

moneypit: I'm thinking of your measurement from one truss to the next truss. If you measure between corresponding points on the bottom chords between two successive trusses, is the rise/run equal to 9/12 (or 18"/24", or any other measurement that produces a ratio of .75)?
Here's a link to an image at the CWC site: Girder and Valley Truss System (http://www.cwc.ca/products/trusses/girder_system.php)
The RUN between trusses is measured along a LEVEL line as viewed in plan (NOT "upslope" along the trusses on the adjoining roof plane), RISE is measured along PLUMB as seen in an elevation. Hopefully the attached image of the trusses in section will clarify what I mean.