# sagging roof on a 1.5 story house



## OldNBroken (Jun 11, 2008)

I'm guessing you have 2x4 rafters then. Without a visual we can only give you ideas. The outer walls of your finished rooms upstairs are what support those rafters. Do you know when the upstairs was finished? Either it has settled since it was finished, which you would notice inside the house. Or more likely the roof was already sagging when the upstairs was finished and the person finishing it didn't think to jack up the rafters BEFORE he built your outer walls underneath it. 

Sorry, I can't think of any easy way to fix it after the space is complete. The good news would be that it shouldn't get any worse though.:thumbup::thumbup:


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## rootdown003 (Feb 19, 2009)

I'm really a noob here, so im not even sure what rafters are, I can tell however that those outer supporting walls are 2X4

The second floor was finished when the house was built in 1944 (plaster walls and all), I'm guessing it wasnt warped when they built it in 1944, this leads me to believe that warp happened over the years very gradually, maybe heavy snow falls didn't help either. it also makes wonder if it could continue to get worse

I guess jacking up the supporting walls now, would probably create all kinds of cracks.


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## Scuba_Dave (Jan 16, 2009)

Rafters are the beams that go up to the peak to support the roof
You may not have the main beam that the rafters rest against
In some cases the rafters merely meet at the top










Outer walls as 2x4 is normal
Where is the sagging, in the middle of the roof?
Or along the edge of the roof?
In some cases roofs were built with the rafters 24" apart instead of the more normal 16". This can cause sagging too


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## rootdown003 (Feb 19, 2009)

I'm at work right know, so I can't check, but I'm preety sure that the rafters are atleast 2X6 and their is a main beam, however it is quite thin I think only one inch thick.

The sag is gradual, from the one end, to the middle where it is the deepest

i'll have to check the spacing of the rafther, from memory I think it is 16 inch.


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## Scuba_Dave (Jan 16, 2009)

A thin main beam is OK, its just to tie the rafters in
The rafter sizes depend upon how far they span
You actually do not measure the length of the rafter
You measure the distance from the center beam to the inside of the outer wall
So you measure along the writing "Rafter Span" in the figure










A 2x6 is good for almost 10', depending upon type of wood
2x8 is 13" 6"
2x10 is 17' 5"

I usually use a 2x10 as a min unless its a real short span
We can get some heavy snow every now & then


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## Clutchcargo (Mar 31, 2007)

What is actually sagging? Is it the ridgeboard or the roof itself as depicted in Scubadaves previous post (#4)?
To me it sounds like the ridge is sagging which would imply that your walls are spreading because the collarties or ridgebeam are inadequate.


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