blown insulation

[Steadyhand]

I have a 99 legend, single wide 16x70. I need to make this home more efficient for the winter and heating. The living room and kitchen have vaulted ceilings with the spackled popcorn texture. The ceilings in the front and rear of the home however are not vaulted. I pulled the master bath exhaust fan and put a camera up into the cavity and found there is minimal insulation up there but plenty of room for more. I would like to put some blown fiberglass insulation in this area. I'm afraid cellulose might weigh too much. I can't see how the ceilings are actually installed nor do I know how thick the ceilings are so I don't know how much weight they can hold. Does anyone have experience with this and any idea how much fiberglass insulation these types of ceilings can support? I can probably get a minimum R13 layer blown up there and not have any weight issues but I would like to fill that cavity as much as possible. I am not too concerned with the vaulted ceiling areas, it is mainly the ends of the home that seem really cool.

I also have one other question. The roof is metal and is supported by thin rafters spaced 3 feet apart. Is this 3 foot spacing normal? I expected a maximum of 2 foot spacing and instead found them three feet apart. I know the roof is just a thin metal but I expected something sturdier for snow load. I am in southern Missouri and we don't get a lot of snow but we do get a good deal of ice from time to time that has brought down power lines, branches, etc. I was hoping to get a new metal roof installed this coming spring with a little overhang on the sides to keep water away from the siding and not too confident this roof can hold much.

[Greg]

Adding insulation up there is always a challenge at best. Both space & access is limited so you can only do so much. If you are doing roof work that would be the time to insulate.

Greg

[yakima4$]

Blow in as much as you can but maintain,1 inch air space below roofing so roof can breathe.
If you re do the roof in the spring you could put on a TPO roof (rubber membrane) and never need to worry again.
Can be installed directly on existing metal.