changing roof pitch on complex roof

[vanderloo5]

Hi All,
I have a nearly completed residential project with a semi complex hip roof with a 6:12 pitch. The client just called me and asked me to change the pitch to 6 1/2:12. I thought I could just select the roof(s) either all together or one at a time and just change the pitch in properties and be done with it. I've tried both ways and I get an error every time that "the roof cannot be joined" when I select "unjoin elements" I get "Can't make roof footprint." The footprint shouldn't change with a pitch change?? I thought this was supposed to be one of the great benefits of BIM. Easy to make changes and changes made in one view are effected in all views. Anyway, is there an easy way to do this or do I have to give my client CPR when he gets the bill for my time for re-drawing the entire roof?
Thanks,
Phil
P.S tried to upload dwfx but got "invalid file"

[cporter.207875]

Did you try modifying the pitch in sketch mode?

[vanderloo5]

Yes, with the same results.
Thanks

[patricks]

Do all roofs truly have the same pitch everywhere, and are they all drawn the same way with the same eave overhang? When I mean drawn the same way, I mean drawn by picking walls and either specifying an overhang distance from the wall face, or from the face of the wall core.

If the roofs are not drawn consistently, then you can have problems when trying to make changes. You can have problems like eaves not aligning, which produces errors like you've seen, among other things.

First I would say unjoin any joined roofs you have. Then go into the sketch mode of each one and change the pitch there. After changing the pitch of the lines, click on the Align Eaves button. It will either say "Eaves already aligned" or you'll see arrows appear with different eave height values. If you don't want to change the overhangs, then you'll have to click on one edge that has the correct value, choose "adjust height" and then click on the other edges that have differing eave height values.

Do that for each roof, make sure each roof is still at the same height, and then join them back together.

If it were me, I would make sure all roof lines are drawn consistently. I would draw the roof lines by picking walls, extending the lines to the core, and then specifying my overhand from the face of the core (face of wall framing usually). This isn't such a big deal for gable edges or edges that are not slope-defining, but it is especially important for the slope-defining edges. By picking walls and extending the overhang out from the roof core, the roof will also properly sit on the wall plate in section, with the bottom edge of the roof's core layer intersecting the wall's core layer at its INSIDE edge, just as it would actually be built.

[davidthigpen]

One issue that could be a part of the problem is the fascia depth. If you missed any of the slopes such that you have a 6/12 and a 6.5/12, Revit can't cut the fascia. Set the fascia depth to a distance such that Revit won't be cutting the roof and see if that allows you to modify the roof.

[vanderloo5]

Thanks for the input. This was very helpful.