The respirator is a lot more comfortable and easy to breath through. Paper masks never last long on my face, it is like breathing through cardboard. The ones with exhalation valves are better.
I really strongly recommend getting the professionals, this is an unpleasant job.
In new construction, cardboard insulation stops are put in along the top of the exterior wall between the rafters/trusses before the roof is sheeted. Rafter vents as described are used in really low pitch roofs or vaulted ceilings where there is little room for insulation. Either one would be a serious pain to install in an existing home. I suspect batts are used in this case to hold the blown in insulation away from the soffit.
The best idea is to fill your pores with talcum powder before you start, no itch’s at all, add a decent mask with exhalation hole and your good to start.
It is if you end up spitting blood for a week or so. Last time I wore a mask I was changing air filters, fiber glass. Took less time and and handle less fiber glass than insulating a celling. The mask leaked I got glass in my lungs, not good.
In my town, to get the professionals to come in spray in the cellulose, you’re probably looking at $1000, give or take. I can do it myself for about half that. I would imagine the price is in the same ballpark down there, but calling an insulator for a quote would be a fairly easy step to get you an accurate number for your region.
A properly fitted paper respirator, with two straps, not one, should get you around 85-90% protection and will do an adequate job in managing the fibreglass particles for the couple hours you’ll be messing with it, but if you’re really concerned about getting crap in your lungs, you need to go half mask and P100 (HEPA) cartridges.
If you want to do a great job that will last, here’s what you do.
Remove all the old insulation and vacuum out your attic.
Ensure that you have proper soffit and ridge venting.
Add baffles in the joist spaces from the soffit to approx. 20" above your rafters.
Ensure any pot lights, junction boxes, HVAC, etc… are up to code sealed, and rated to be enclosed within your insulation.
Hire an insulation company to “butter” coat your whole attic floor with 1-2" of closed-cell sprayfoam, this will give you a seamless vapour barrier, added R-value, and stop any roof leaks coming right through you ceilings.
Blow in approx. 16" of cellulose insulation.
This will give you the most efficient attic space with a proper vapour barrier, no mold or moisture problems, and an R-value of 50+.
I bought the encapsulated fiberglas stuff and put it in over the original insulation (which happened to be installed w/the paper facing the wrong way. How do you do that when it says “This side toward heated area”?) Easy to use and very little dust.