Roof sagging? - InspectionNews

John Stephenson · #1 (**permalink**) 05-15-2007, 06:38 PM

Maybe hard to tell in photo, but do you thing this type of sagging warrants repair? I didn't see any "obvious" issues with the truss framing. (1983 home on slab foundation)

wayne soper · #2 (**permalink**) 05-15-2007, 06:56 PM

This is partially caused by the doubled shingles or Ice dam retarder at roof edges. No, repairs are not required, unless excessive deflection is noted at the roof rafters. Meaning, if rafters were set crown down and all are sagging indicating poor framing practices then, installation of a knee wall at attic would be recommended.
How old is the home. If 20+ years the framing would not comply with today's standards but if holding loads properly there is not a problem.
Did you walk on it. Was there bounce in the structure. Were you afraid for your life. If yes, there is a problem. If No, Typical 1970's roof framing.

John Stephenson · #3 (**permalink**) 05-15-2007, 07:14 PM

Ha! Too funny, Wayne.

Yes, I walked on the roof! No "bounce" in decking.

I was only afraid of the 5 squirrels that kept running around on the roof!

Frank Kunselman · #4 (**permalink**) 05-18-2007, 11:54 AM

Truss Roof you say. That sure looks like a ridge cap and a 4 to 5 foot span of sag at the ridge. I've never seen the gusseted ridge of a truss sag like that before...trusses are 24' oc aren't they?

Are these scissor trusses? If the span of the sag is 4 ft or more you might want to investigate further...broken truss maybe???

Jerry Peck · #5 (**permalink**) 05-18-2007, 05:39 PM

A lot of time the trusses are set in proper alignment with each other, or are (what! how can that be?

) not all made where they are in proper alignment with each other when set.

Set one or two trusses back just a little from the ones on either side and there 'will appear to be' (because 'there is') a dip in the roof right there.

*IF* the trusses are built correctly, you will see a matching raised ridge on the back of the roof where the dip is on the front. However, if the trusses are 'not quite right' in size, the back roof slope could very well be (likely is) flat and in plane.

You would be surprised how well that telegraphs through the roof covering even when the roof covering is tile.

Eric Barker · #6 (**permalink**) 05-19-2007, 03:31 PM

I will sometimes have homes where at one end of the attic they run the ceiling joists parallel to the ridge (attached). The rest of the joists are perpendicular to the ridge.