Have you priced doing a combo of a thin layer of spray foam and bat? I'm in central Kentucky also and currently trying to weigh the benefits of energy efficient upgrades over the long run (such as, if it is worth it to upgrade to a geothermal heat pump).

See below for the minimum R Values required in Kentucky under the IECC 2009, which is Code there.

If you weren't using foam between the window frames and framing I hate to think of the alternative. If you have no experience with the foam, be sure to use low or no expansion foaming specified for windows and doors. Expanding foam can crack and distort framing.

Source:http://energycode.pnl.gov/EnergyCodeReqs/?state=Kentucky

This post was edited by worthy on Tue, Feb 18, 14 at 11:46

Kinsley,
Have thought about the combo, but with 2x4 walls I don't think it would be possible. Would have to mash the bat insulation which from my understanding defeats its purpose. We are also considering the geothermal system, but haven't got a quote on it yet.
worthy,
Thanks for the suggestion for the specific foam for windows/doors. I'm assuming the alternative to not using foam around the windows is nothing at all. I think most homes built around here do not put anything around the gaps between the windows and the framing. I was thinking it would be a good idea to use the foam around the window/door gaps, and also to fill the joints of the OSB boxing. Does anyone use the foam to go along the edges of the studs?

Do you have a GC or are you overseeing everything yourself?

Kinsley,
I am overseeing it myself. How about yourself?

I'm not sure yet, my husband wants turnkey and I want to do some of the work myself. I need a lot of help in the earlier stages of construction ( foundation and framing) and I feel more confident tackling the finish work ( flooring, cabinetry, ect.) I spend all of my free time reading about the process. I've drawn the floor plan I want and now need to have a draftsman put it into CAD and make it buildable. We have land already and I just want to dive headlong into it and get started, by husband is slow and methodical about everything....so we're having a tough time getting started.

Kinsley,
If you are close to Lexington, I can reccomend TLC Designs. You can Google it, there is a website. He drew our plan. His cost is very reasonable.

Yes, I am very close to Lexington....thanks so much for the info. I'm open to suggestions if you have any subs you really like working with. I have chosen our contractor for septic installation, but that's all I've got so far ( I guess I'm putting the cart before the horse).

Have you considered 2x6 studs on 24" centers? Studs are responsible for a lot of heat loss, and reducing the number cuts down the heat transfer.(And your house won't fall down! ) 2x6 studs give you a nice big cavity to fill with insulation. If you are not familiar with it, google "advanced framing techniques".

You might also look into sprayed in cellulose insulation, with spray foam used first to fill all the obvious narrow spots/leaks where cellulose won't get in. If you can't afford spray foam everywhere, I'd for sure buy some cans can fill every space you can around windows/doors, etc. We are building an energy efficient house in middle TN, using advanced framing with a combo of spray foam and cellulose insulation. Our old house leaks air like a sieve, and we aren't going to freeze anymore. You get colder winters than we do, so good insulation is a wise investment (and not something that you can easily fix or add on later).

Kinsley,
I sent you an email.

genie,
We did consider 2x6, but it may put us over budget with extra costs. I will use the can foam for edges of studs, OSB joints, and around windows/doors. I'm hoping that will make a difference in efficiency.

Foam around windows should be pretty standard. Foaming between OSB is a nice DIY thing but good caulk is probably better.

What are you heating with?

I think the best bang for your buck would be a layer of rigid foam over the sheathing. Even an inch will essentially break the thermal transfer through the studs, and your wall will actually perform at R-13 plus. Better yet is to apply two layers of foam, stagger the seams, and tape the seams. This controls air infiltration as well, another major factor.

Exterior foam over (or instead of) sheathing is becoming the default system for new houses in colder climates under the International Residential Code, which is the basis for virtually all US state codes.

Gaskets under plates and caulking at the intersection of framing and between the members of built-up posts works better than foam.

See link for other spots to air seal.

Here is a link that might be useful: Air-sealing Your Home

Why wouldn't you use blown in cellulose? It's a step up in sealing the voids, a little higher in cost but not nearly the jump in dollars as spray foam...

Jen

PS...
I'm very near Lexington too, probably have the same energy rater as you (possibly). He was very impressed with our blown in cellulose/spray foam/bat combo. We used bats for basement to first floor insulation, blown in on all vertical planes, blown in for part of the attic space and spray foam on the diagonal roof/ceiling and around dormers. We have a 1.5 story. All windows were spray insulated and all bands. Our hvac for upstairs is in its own closet on the second floor, for efficiency and the ducts are insulated into the living space. Main floor hvac is in the basement, which does get colder in winter but doesn't strain the system in the summer months like a hot attic can.

If you are looking for subs I can tell you who we quoted with, ran from, and ended up using.

We self GCed and did some work ourselves.

Jen

Jen- that sounds like a really good set up.....we are on rural electric and want our new house to be as energy efficient as possible. I am interested in your input on central KY subs also.
-Thanks

I know I have posted this other places but here is the run down of what we have done.

Couldn't find plans suitable for our land/needs/wants. So we drew them up ourselves. Took those sketches to 2 lumber yards. Lumber king in Danville was amazing, they put them into cad, calculated all spans/beams required etc. for free. We then in turn used them for lumber materials and the Amish framer they suggested. We already had an awesome excavation crew (patton excavating) and concrete team (Douglas I think I have to check the company name). Loved them both!. We had the Amish (chris detweiller) dry it in, roofer (Devine roofing Harrodsburg) awesome price and techniques, used special material around the dormers to help prevent leaks. Hvac quoted quite a few places went with comfort h&a, very pleased. Insulation... Quoted some big guns and small, I won't mention on here the outrageous people. Ended up going with a local co. that new his stuff. Suggested the hybrid system, didn't push any one product but did steer towards the cellulose over all bats. Very knowledgeable.
We did the siding (horn home improvement-great price), electrical, decking, plumbing, painting, hardwood flooring ourselves (Monticello 4" red oak grade 2), trim(eventually will get done).
There are random pics all over this website showing our progress.
Jen

People have touched on it but insulation specifics are practically meaningless without a certain level of airtightness. Airsealing is much more cost-effective than insulation for the level of building that is common in 2014.

Although your local code is based on the 2009 IECC, the current international code prescriptive minimums are found in table 402.2 of the 2012 IECC which requires insulative sheathing in your climate for wood framed walls. If you are going to live in your house for more than 4 or 5 years I think it would be wise to meet the poorest performance allowed by international law for a cost-effective approach to weatherization.

The 2015 revision is quickly approaching and I suspect there will be updates to the blower door test minimums which is where you should be paying the most attention if energy efficiency is important to you. Without blower door test goals and proven measurements, upgrading insulation is a waste of resources.

Here is a link that might be useful: GBA aritcle on 2012 energy code

We caulked like crazy people, and are soon to be doing our blower door test which the rater is thinking we will come out very well on. We had him out at every possible opportunity to help guide us to the best energy saving techniques possible. You have to watch subs and their knowledge here. Hvac/insulation is new to the inspections here and some are MUCH better than others.

2012 IECC which requires insulative sheathing in your climate for wood framed walls

Minor errata

From the linked GBA article:
"... for the first time, builders in climate zones 6, 7, and 8 will be required to install exterior rigid foam insulation (or to use some other comparable wall insulation strategy)."

The OP is in Zone 4.

But the point well taken is that exceeding Code minimums is usually a moneysaving idea. (I remember building homes when a nominal R12 in the abovegrade walls was "state of the art" in our cold climate.)

Woops! Thanks for that correction Worthy. I was thinking KY was in Zone 5 and that 5 had the requirement. Iam sure there are some elevations that would be very similar to 5 or 6..

The 2012 IECC prescriptive minimum requirements for walls in zone 4 is R20 if you dont use insulative sheathing. If you use insulative sheathing it would be cavity R value of 13 + R5 insulative sheathing. This would represent the poorest performance allowed by international law.

Thanks for the info jenny. I sent you an email asking for additional information.

Brian,

When you talk about insulative sheathing, I'm assuming it is the rdigid foam board. Do you suggest using that over top of the OSB or use it alone? Years ago in my area the ridgid foam board was popular, but seems to have disappeared. I am bricking the home, so would that make a difference? Thanks

Insulative sheathing might be the wrong term now that Tyvek is making an insulated version of their product which would fill the requirement. Ive always used the term "continuous insulation" which might be better.

Weve had good success lately with ZIP+R sheathing and Mineral wool is another option but foam board is the most common option by far.

The trick with brick is to get the details right with the airspace between it and the framing/sheathing. Mortar nets, weep hole spacing and vents at the top of the wall are important to get right. I think 1-2" of faced XPS or foiled Isocyanurate would help resist inward solar vapor drive better than a more permeable housewrap.

Most of the insulating methods mentioned should not add big bucks to your project. If going to 2x6 walls is a budget breaker, its time to re think your budget and put your money into building a quality shell home and less on finishes (assuming at this point on a higher interior finish quality). I too vote for adding the r5 to the 2x4 walls. Thermal breaks are big on performance and comfort. Use a quality caulk instead of spray foam for sealing your studs. Caulk is a lot easier to make sure you have a good seal. Spray foam, especially the canned stuff, can be hard to control and get a nice bead.
The above mentioned recommendations is something to consider, especially after the winter we have had and are still having (im right in the middle of the blizzard warning here in Iowa). Increasing your shell is your only place in your house you will see a pay back on investment.
Also keep in mind, meeting "code" as like Brian said, its the lowest requirement you can have to build the home.
You will notice bumping the roof to closer to r50 and the walls up to closer to r20.

What specific caulk do you all recommend? We are getting ready to break ground on a new home in AL. All permits and prints are complete and we will have 2x4 walls. I don't see anyone in this area using foam on the outside of osb or the zip it.