Insulation

nicholas bonham-carter

what about putting the batts of insulation on the floor of the 3rd floor?when you have completed the wiring then put them in the attic.
your berry hotel looks like an interesting project good luck!!
is the propane tank the same age as the building?--nbc

LoriMae

Would Attic Insulation Really Matter

in this situation:

Three story home in North Dakota. The third floor has nine foot ceilings and is sealed off in the winter. The roof is flat with a slight pitch going from approx. one foot to three feet.

The entire third floor needs to be rewired (several years away from doing that) and I was trying to avoid insulating until afterwards.

Should we go ahead and insulate?

Weezbo

no not if you have an unlimited source of fuel.

just thowing my typical curve to a question...

certainly insulate .... and remember this, once you pay for IT , it is a done deal.. fuel on the other hand seems to have a slightly different "Value".

LoriMae

Wouldin't 9 feet of

dead air space have an approx. R value of 27?

Weezbo

i appreciate the idea of heating unused space

buh unless you are in need of the area why heat it at all?

i assure you my home will not benefit from your attempt to heat the state of Dakota from your house. though someone out there in a bush village may be able to keep their fingers and toes with the same energy were it available to them in the winter. look at it like this, if you think it is no big deal multiply what you are saying by 350 million people..

in a way it is a form of social responsibility to insulate ,ventilate and heatilate your home to the best of your ability.

some times the bigger picture gets lost in our day to day activities....if it is true for me then its true for you...

or to say that another way i would not have you do something that i wouldn't couldn't or shouldn't do . for years , decades i have had an r 71 in the lid of my home. this year i am seriously considering bumping that up to r-100 every where i can and adding another r-20 to the walls for an r 50 ish realm..once it is paid for i can rest assured it will slow the roll of heat to the cold for years to come. i just happen to be buzy as heck at the moment and 'really must go'..as the old song goes..

Brad White_189

Nine Feet of Dead Air...

LoriMae, 9 feet of air will not be "dead air" by any definition. Most so-called dead air spaces cease to be so when over 4 inches. That is enough to set up inter-fluid convection and negate the benefit.

If sealed from the house will it act as a buffer? Sure. Consider if the R value below is equal to the R value above and the space is tight to the exterior, your average temperature will be halfway between your indoor and outdoor temperatures.

The biggest benefit to proper insulation (and I am speaking about foaming all penetrations and joints then using an open blow cellulose or closed-cell foam system alone or in combination) is air sealing.

If air cannot leak out it will not leak in and attics are the top of your thermal chimney.

LoriMae

It was a dumb question,

but I thought I would give it a shot. Time to figure out how much I need, rent a blower, and get down to it.

Thank you for replying!

Brad White_185

What?

There are NO dumb questions, LoriMae. Get that out of your head.

If you are planning to do an open blow in the attic floor, renting a blower is fine. Buy good material, the best you can afford. It should have the appropriate UL labels. A recognized brand such as NuWool, Greenfiber Cocoon among others. No "Brand X" or off-label products.

If truly an open blow (no floor boards or walking surfaces) be generous with the material. If blown between joists but below boards, strive for maximum density. Before you do this though, you have a blank slate! Time to go over the plumbing, wiring and other open chases in detail (IN DETAIL) with canned foam. Be bold and seal those gaps. You will not likely ever do this again so do it once.

(Last summer I removed R-75 of old insulation due to raccoons using my attic as a cheap hotel. NOT fun, but once stripped out and cleaned, the opportunity to seal the attic floor was presented. I got a second chance, you will likely not.)

If you DO opt for a professional installation, seek a "Dense-Pack" application. If they insulate the rafters, a non-woven mesh is stapled across the rafters and the material is blown to a decent density, definitely not a DIY project.

I have seen this done with a wet-spray (damp spray really) on a new house in RI. I did a blower door test and even unfinished (without window trim) it tested out to 0.10 Air Changes per Hour (ACH). It was so tight it needs a heat recovery ventilator, but that is a nice problem to have.