installing R panels over existing rolled metal roof

[mvintx]

Hello all. Been awhile since I've lurked here but now I've got a new problem. Had a major hailstorm last week and it punched holes and tears in my rolled metal roof. This is a '97 Fleetwood 16 by 72 that we've lived in for the last five years.

One contractor says he can put down 1 by 4" lathing screwed to the rafters and then screw 26 gauge R panels directly to those. Another says you don't need the lathing, just screw the panels into the rafters (which appear to be 24" on center).

Is there a right/wrong way to go about this? The $$$ difference is not that much between the two contractors but I want the job done right.

[Greg]

Most of us here would go with adding lathing (and insulation) over just laying new over old steel.

See the "Articles" section for the way Mark Did one.

Greg

[JD]

I agree, definitely use lathing strips. The placement of the screws is very critical to this type of steel panel roof. Having all the trusses end up in the right place is like winning the lottery. Well, maybe not that bad but a bad bet none the less.

Also, fill the cavity between the lath strips with foam board insulation and I would use Ice & Water Shield under the lath strips. This will add quite a bit to the roof material cost but well worth it.