Cellulose Insulation
Any expert opinion on the practical difference between R38 and R49 cellulose insulation for attic blow in? We know the higher the number, the better, but in a brownstone, is it worth an extra $1,000?
Any expert opinion on the practical difference between R38 and R49 cellulose insulation for attic blow in? We know the higher the number, the better, but in a brownstone, is it worth an extra $1,000?
Hi,
This is unrelated to this post, but I saw your comment to somebody’s request for a color consultant recommendation and I need one, too! Yes, it’s late and we’ve been going round and round on color choices (again) ;). Would you please email me the contact info?
Thanks,
cara.muller@gmail.com
I agree tentatively with the above comments – weight would be my first concern, air infiltration is a huge concern as well. The fact of the matter, there isn’t enough info here to answer the question. How is the rest of the house insulated, what are the window u values, how is the air sealing?
R48 is significantly better than energy code and eventually will pay back the $1000 in heating/cooling bill reduction. Payback period depends on variables listed above.
Installing an HRV for constant fresh ventilation is a must for an air tight home, but the units themselves are more than $1000, not including labor.
for attic only i’d be concerned more about weight and the ceiling. however, as a result the stale air will accumulate more upstairs than previously with a higher r factor if there is no other source of air exchange. if your walls are not insulated its a little less of an issue, but i sense it is more of a factor than many people are aware.
The problem in old construction is not not heat loss from thermal radiation. The problem is draftiness. Anything you blow in will help with the drafts. There is no need to go deluxe with the material. Weatherstripping the roof door/hatch/skylight will probably make twice as much of an impact than anything you blow in.
R38 is adequate. I would not say “the more the better”. The insulation is heavy and will press on the ceiling and heavier insulation might deform the ceiling. Also it needs ventilation to work. If they will fill the atic space up to the roof you will get less ventilation and condensation issues.
all been said – go with R38 as the rest of us. you can spend $1000 on lap dances.
Have you done a blower door test, this will give good information relating to insulating your brownstone.
The R38 should be fine.
My checklist
1. Blower door test – this will find any other issues
2. Insulation along with air handlers to supply fresh air.
Spend the $1,000 on air handlers – this holiday season give your family fresh air in your tightly insulated brownstone.