Expert: Dan Griffin - 5/19/2009

Question
The Ceiling in our Double Wide is a Cathedral Ceiling and Constructed Roofing, OSB, Insulation and 2x6 on 4 ft. centers. The Roof and Ceiling together have a bow in three different areas of the Roof. My question is would it be possible to Build 4 ft. sections and Cut out the old ceiling and roof in 4ft. sections one at a time and Replace it without taking off all at the in  same time?
Thanks
Charlie

Answer
Charlie, if the roof decking is not rotten and is simply bowed down I don't think you need to remove it.  You already know things will get messy, no matter what you do.

I would plan on removing all the interior ceiling and add another set of rafters between the existing to provide 2' centers.  You could also jack up a bowed rafter and add another along side it, well nailed.  This is called sistering a joist or rafter.  YOu may need to consider repulling some electric feeds if they are going through the rafters.  Doing it this way leaves you in the dry for the whole project.

If the sheathing has to be replaced, I would still put in rafters on 2' centers and sister ones in bad shape.  It would be much better to lay full sheets that are staggered in each row.  This can only be done by opening up most of the roof at one time.