I've had cellulose blown in on top of batts. Don't do it. One or the other. PITA if you have to move the mix to get at a light or something from above. I would look into the soffit/roof vent situation.
Id go batts myself.. I would only blow insulation in a floor or wall I couldnt get into without allot of work.
Use my above reply to build a "catwalk" where you would normally walk? Soffit and ridge work the best because it uses "chimney effect" to cool the roof...the more directly and focused you can provide a source of cool air that is directed "up and out" the better IMO...but I'm no attic expert, just have done a ton of research on it while trying to decide how to handle insulating mine.
Hmm... I’m not sure if the ridge got vented when the metal went on the roof. I’ll have to take a look at that. I wouldnt be a big deal to drill some holes in the soffit and put some Vents in. I picked up some caps and spray foam for the recessed cans and other openings in the ceiling. I’ll do a better inspection while I’m up there doing that.
Gable vents supposedly never worked except for maybe when the wind was blowing from just the right direction. Or maybe minimally effective is the bettger way of putting it. Soffit venting is supposed to be like the intake of a wood stove and the ridge vent like a chimney. I have gable vents. At one point years ago they put metal vents in the roof and covered up the gable vents. When I redid the roofing 5 or 6 years ago I added soffit vents, ridge vent and freed the gable end vents. Some say I should have left the gable vents covered but I figure every bit of venting helps if they are functioning as exhaust vents rather than intake vents. If they tend to function as intakes with soffit/ridge then I'm wrong. Shoveling blown in insulation like snow isn't so bad. shoveling it on top of batts is messy, messy, messy.
Gable vents do work...just poorly...rely on breeze more so than the chimney effect of soffit/ridge vents
So, I’m not sure that it would be possible to do soffit vents in the front of the house as there is a knee wall the length of the front on the inside and a 3rd of that outside is a porch. So would only having the soffit vents on the back side of the house only be effective. Here’s the start some hats and some foam. Wife is starting to back pedal on the recessed light. She didn’t think it would turn into a project. I may not have to go up there after all! Lol
Anything with batts im a big fan of Roxul over fiberglass. Great sound Deadening and critters don’t make nests In it. Also better at stopping air transfer
Yeah, whenever my wife starts a sentence having anything to do with the house or property with the word "just....." run.... run for your life, run like you mean it. 'Cause that 'just' is going to take 10 minutes plus two weeks, cost between $1.50 and $2,000.00 and cause at least one of us to use most of our very worst words. Sometimes it causes me to use all of my very worst words in new and interesting combinations. Every. Single. Time. And we have been married nearly 40 yrs. Brian (who is 'just' sitting at his desk)
Foaming the roof may be a good solution, especially for a cape cod. It will bring all the knee wall space into conditioned space. I hope there was a misunderstanding with the doing both though, the roof and the blown-in floor. There is no reason to do both. The nice thing about doing the roof with foam is that you don't need to worry about knee wall insulation, floor insulation, or ventilating the attic. Its something to consider.
I love Roxul but so do the mice. While they may not nest "in" it, they are certainly happy to carry it elsewhere to make a nest. I regularly open a toolbox drawer to find mouse nests made of Roxul. I'm not discouraging your use of Roxul, just tempering some expectations.
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Not completely sold yet on the spray foam against the bottom of the roof. It’s relatively new, at least around here. Several builders who have dealt with roofing and insulation their whole lives are wondering what the roof sheeting is going to be like in 15 or 20 years with wood sealed between ice & water shield on one side and 6” of spray foam on the other. 20 winters of 10*on the outside and 75° 6 inches away on the inside is probably hard to duplicate in laboratory testing
Plus, 2 x 6 rafters on a Cape Cod are the devil. No one in their right mind would ever build something like that
I spoke with the guy for quite a while there was no misunderstanding on my part. Perhaps he didn’t know what he was talking about. He was obviously a salesman I doubt he had ever installed any insulation. While foam is probly a good solution it’s not really an option I’m considering. Mainly because I’d have to pay someone to do it. I’m the type of person that is rarely happy with other work.
