I'm just not going to have the time to learn enough and spend enough time to coach my crews into building a super green house, so I'm hoping conventional processes will be enough to make us happy the next 15 years. Drywall, 2x6 walls, plywood, and house wrap with vinyl siding. He will let me work on whatever I want, so what I'd like to know is: Blown in cellulose or fiberglass for walls? Which is better? Should I caulk all the seams at the studs and exterior plywood? What else can I do to tighten the house? Should there be insulation between the footers and the foundation? Should I put foam under the basement floor, if so, how much? Should there be foam between floor and poured basement walls? Can I use a false ceiling for installing LED can lights to keep heat from escaping out the ceiling? If I do radiant flooring, is it OK to have the AC delivered from the ceiling, eliminating floor vents? Seems like having the AC naturally fall would make more sense anyway. We have both flat ceilings, and vaulted in the master bedroom. Should both just have blown in insulation over the drywall? Should I use a ridge vent for the attic? I'd like to have a remote exhaust fan for the kitchen stove so it's not so loud, is there such a thing? Same for bath fans? I assume I need two fans in the master, one for the enclosed toilet room and one for the bathroom? This is such a pain! I have literally spoken to 15 different contractors, general contractors, framing contractors, etc, some of the best in my area. And all of them say I'm wasting my time. I was really hoping to do the 2x4 walls with the 2" foam on the outside, but we're already a year past wanting to start this house and I really don't want to pay for a divorce :) Thanks for any advice...

OK I had all these items separated out into bullet points, it's too bad it didn't keep that formatting. I don't usually run on a bunch of different thoughts that way.

What's your zip code? I'd take cellulose over fiberglass. Damp sprayed is fine. How about putting strips of polyiso insulation over the interior edges of studs to get a thermal break (and more room for cellulose). I'd tape the external plywood for air sealing. A vented attic with loose cellulose works well. Seems like an inline duct fan would work fine for low noise ventilation.

52726

At this point, concentrate on air tightness.
Blown in cellulose or fiberglass for walls? Both work, but neither is air tight, so you need to look for another way to tighten the wall.

Should I caulk all the seams at the studs and exterior plywood? YES

What else can I do to tighten the house? Use ZIP sheathing and tape the seams. There will be no tape at the edges, so make sure the framers caulk the studs at those locations.

Should there be insulation between the footers and the foundation? There should be a rubber gasket - cnservationtechnologies.com
then FOAM the inside sill/rim joist are after framing

Should I put foam under the basement floor: Absolutely - impossible to do later!!! 4" of XPS + ploy on top

Should there be foam between floor and poured basement walls? YES!
'
Can I use a false ceiling for installing LED can lights to keep heat from escaping out the ceiling? Yes.

If I do radiant flooring, is it OK to have the AC delivered from the ceiling, eliminating floor vents? Seems like having the AC naturally fall would make more sense anyway. ??

We have both flat ceilings, and vaulted in the master bedroom. Should both just have blown in insulation over the drywall? Yes

Should I use a ridge vent for the attic? Yes

I'd like to have a remote exhaust fan for the kitchen stove so it's not so loud, is there such a thing? Yes Same for bath fans? Yes - FANTECH.com

I assume I need two fans in the master, one for the enclosed toilet room and one for the bathroom? This is such a pain! that will work

I have literally spoken to 15 different contractors, general contractors, framing contractors, etc, some of the best in my area. And all of them say I'm wasting my time. I was really hoping to do the 2x4 walls with the 2" foam on the outside, but we're already a year past wanting to start this house and I really don't want to pay for a divorce Thanks for any advice...

Thanks so much Bob.

Can you expand on a couple of things:

When caulking the studs and exterior plywood, is it better to caulk the interior cavities, or caulk the outside of the studs, then in stall the plywood so the caulk is sandwiched?

What is ZIP sheathing, and what kind of tape? And why couldn't I put tape at the edges?

Can you expand on foam the inside sill/rim joist after framing?

How much foam between the basement walls and floor?

Any other little things I can do without affect the timeline...

Thank you!

In Ann Arbor Mi, which is likely a little colder then you; XPS has a pay back of 30 years for 4 inches, I think 2 inches has a payback of around 7 years at current heating costs.

I grew up there It's a tad colder but pretty darn close. I always argue a bit when people say "at current heating costs", because they usually only go up. Having said that, I appreciate the thought because we likely will only be in this house 15 to 20 years. So I'll do at least 2" and maybe 4" if budget allows... thanks!

When caulking the studs and exterior plywood, is it better to caulk the interior cavities, or caulk the outside of the studs, then in stall the plywood so the caulk is sandwiched?
Aren't you having problems finding contractors that will build a tight, well insulated house? If so, what makes you think they'll caulk each stud well enough to prevent amor leaks? You can SEE the tape after the work is done.

What is ZIP sheathing, and what kind of tape? And why couldn't I put tape at the edges?
http://www.huberwood.com/zipsystem/home-zip-system

Can you expand on foam the inside sill/rim joist after framing?
We spray 3" of closed cell foam starting at the top of the foundation and extending to the subfloor - that seals most of the leaks around that area.

How much foam between the basement walls and floor? A 2" x 4" piece of EPS or XPS will act as a thermal break and keep the outside concrete from cooling the floor.

Any other little things I can do without affect the timeline... Buy a foam gun (+/- $40 where you can find them, or online (https://www.amazon.com/Foamnseal-Polyurethane-Foam-Dispensing-Tool/dp/B00F2ZGTJE/ref=sr_1_7?s=hi&ie=UTF8&qid=1475331975&sr=1-7&keywords=foam+gun) and use it every day on gaps in framing, holes, around windows and doors (use low expansion foam there)

that should have been AIR leaks, not amor leaks

"XPS has a pay back of 30 years for 4 inches, I think 2 inches has a payback of around 7 years at current heating costs"
There is a valid argument to be made for using 4" of EPS (XPS also works; especially recycled) under a concrete slab as opposed to 16". IMO There is no valid argument for using 2" instead of 4". Just look at the cost of adding another layer in ten years when the cost of fuel has doubled.

A good rule of thumb (financially) is that improvements that aren't reflected in the future sales price should pay for themselves (using build-time fuel prices) while you live there. Sure, fuel prices go up, but on the other hand, you have to pay for the improvement up front.

The primary air sealing should be with tape and gaskets - not caulk.

I realize that many builders and homeowners believe this, but many of us build homes that we hope to be useful and comfortable long after the current owners and us are gone. Probably comes from living in an area with dozens of two hundred year old homes that were built to last, and have done that.

I realize that many builders and homeowners believe this, but many of us build homes that we hope to be useful and comfortable long after the current owners and us are gone. Probably comes from living in an area with dozens of two hundred year old homes that were built to last, and have done that.

Unless you have permafrost there is never good reason to use 4" of XPS below the slab.

I believe the best way for a homeowner to assure a tight house is to skin the inside or out depending on the siding, with at least an inch of polyiso--I like Thermax. You depend on the quality of the product and personally inspect the installation noting the specified sealing technique and materials used. You will also have the unequaled benefit of negating thermal bridging giving a true finished wall R-value.

Badger, why do you like an obscenely expensive polyiso? If its covered, you dont need Thermax, save your money and buy normal polyiso, without the chemical additive.

I say no to tapes as far as air sealing goes. A blower door test will estimate for you the size of the hole your house has, and its inevitable that there will be a volume represented as a hole.

Now you can tape over some of the holes or you can fill it with sealant or foam or a gasket. At some point, both strategies will fail, the tape lets loose or the caulk and/ or foam debonds. If the tape fails you are basically back to square one, your "hole" area is close to the same as if you did no air sealing, if the caulk or foam debonds the leakage path is still basically filled and your leakage backtrack is less.

Put another way think of leakage as an open window you cant close, so you tape over it. When the tape falls off you have an open window, if you fill the opening with any material that doesnt disappear, but it cracks around the edges, you still have basically a closed window. And yes, ive tried tapes and they're nice and convienant, but I dont trust them.

Why Thermax? Quality. I hate waste and sub-par materials create waste.

This is a wall system, and as such requires some understanding of the proper application.

http://building.dow.com/en-ca/solutions/wall-systems/thermax-wall-system

I used foam to seal some sheets and tape for others depending in the application. I trust Dow Chemical to know how to apply their products.

http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0951/0901b80380951d7d.pdf?filepath=styrofoam/pdfs/noreg/179-04646.pdf&fromPage=GetDoc

I have used various XPS products on the exterior with 2" of 2# foam blown on the inside of the house sheathing finished with fiberglass blown or batted easily achieving a true R-20+ but you can't get there in a 2x6 wall without effecting thermal bridging.

Thermax also allowed me to reduce solar gain to near zero, save that attributed to windows.

Any polyiso will work, but Thermax is the leader in quality for my money.

https://law.resource.org/pub/us/code/ibr/icc.iecc.2009.html

I think its important to note the link you provided per Dow is intended for steel frame commercial applications using thermax specifically for its fire rating to meet certain commercial requirements over normal polyiso.

Further in Dows site they explain the difference between their regular polyiso and their thermax brand, the only difference per Dow is the fire rating, 190F for regular, 250F thermax, and available facings they put on the sheet, same company offering. As a start with same facings your paying double for the same product, regular $15 for 1" regular, $30 for 1" thermax.

You like Thermax, thats great and maybe your paying for the facers for some reason, just wanted to inform readers of the realities, and I myself typically buy thermax for inside unfinished basements, but I would never use it on an exterior or behind drywall, their is really no point in residential to throw the money away.

Posted By Bob I on 01 Oct 2016 10:28 AM

When caulking the studs and exterior plywood, is it better to caulk the interior cavities, or caulk the outside of the studs, then in stall the plywood so the caulk is sandwiched?
Aren't you having problems finding contractors that will build a tight, well insulated house? If so, what makes you think they'll caulk each stud well enough to prevent amor leaks? You can SEE the tape after the work is done.

Well one nice thing is the contractor is going to let me do whatever work I want, and I have help. While there's no way I have time to frame the whole house as we want to get it closed up before winter, I certainly could get a couple of experienced builder friends to help me sheet the house. In that case, I would know that it was caulked.

Posted By Bob I on 30 Sep 2016 07:29 AM

Should there be insulation between the footers and the foundation? There should be a rubber gasket - cnservationtechnologies.com
then FOAM the inside sill/rim joist are after framing

Link doesn't work, I tried putting an "o" in to make it conservationtechnologies.com but that brought up a museum preservation link or something like that....