Any problems with unfaced insulation on exterior walls?

[EddieWalker]

I am to the point that I am fixing to insulate my hunting camp walls, I used house wrap on the exterior over the OSB and am thinking about using unfaced insulation on the walls due to cost and was wondering if faced insulation would create moisture issues , so my real question is can I get by with unfaced insulation in the exterior walls without causing me any issues with moisture down the road?

During the last ten years, there was a huge push, funded by massive amounts of government money, to go green and create super efficient homes. The so called experts and super smart people tried just about every method possible to get any measurable improvement out of a house. This is kind of like car enthusiasts looking to modify their cars by what is used at NASCAR. They where mostly all successful, but at extremely expensive results. Spend $50,000 more on a house to save $50 a month or less on energy. In some cases, there was no measurable improvement on what was actually spent heating and cooling a house.

Fine Home Building magazine has been all over the place on this. It's kind of fun to see what the experts have come up with, but not to have to pay for having it done.

Some home builders also got into the act and tried to figure out how to meat the new requirements that where being passed in some cities. What they found out was that getting the best, air tight seal you can have on the exterior of the house gave you the greatest measurable improvement in efficiency. Insulation only plays a small part in keeping the temps inside a house where you want it. Wind and air flow where the biggest challenge. A variety of house wrap materials where tried without any significant changes. Tape helped, as did caulking every exterior penetration.

What was found to give the best results was a rubber type paint the flexes with the house, but keeps out air and moisture. There are a few different names and brands out there, RedGard is the one I like that's sold at Home Depot and also used for showers. Zip System is based on this type of material too, but you use a special type of tape to seal the edges to make it air tight. Cost wise, zip system is cheaper then the rubber type paints.

Housewrap in a Can: Liquid-Applied WRBs - GreenBuildingAdvisor

As to your question about faced or non faced insulation, it really wont matter either way.

 

[RayfromTX]

During the last ten years, there was a huge push, funded by massive amounts of government money, to go green and create super efficient homes. The so called experts and super smart people tried just about every method possible to get any measurable improvement out of a house. This is kind of like car enthusiasts looking to modify their cars by what is used at NASCAR. They where mostly all successful, but at extremely expensive results. Spend $50,000 more on a house to save $50 a month or less on energy. In some cases, there was no measurable improvement on what was actually spent heating and cooling a house.

Fine Home Building magazine has been all over the place on this. It's kind of fun to see what the experts have come up with, but not to have to pay for having it done.

Some home builders also got into the act and tried to figure out how to meat the new requirements that where being passed in some cities. What they found out was that getting the best, air tight seal you can have on the exterior of the house gave you the greatest measurable improvement in efficiency. Insulation only plays a small part in keeping the temps inside a house where you want it. Wind and air flow where the biggest challenge. A variety of house wrap materials where tried without any significant changes. Tape helped, as did caulking every exterior penetration.

What was found to give the best results was a rubber type paint the flexes with the house, but keeps out air and moisture. There are a few different names and brands out there, RedGard is the one I like that's sold at Home Depot and also used for showers. Zip System is based on this type of material too, but you use a special type of tape to seal the edges to make it air tight. Cost wise, zip system is cheaper then the rubber type paints.

Housewrap in a Can: Liquid-Applied WRBs - GreenBuildingAdvisor

As to your question about faced or non faced insulation, it really wont matter either way.

I'm not sure what you are referring to in your first paragraph but would like to see links to what it is. The Building America program and the department of energy have a pretty small budget but the DOE programs cover appliances, lighting and air conditioning systems and most of the advances and requirements for energy savings in these areas have come from the requirements that came from those programs. The fact that your refrigerator uses 1/4 the energy it did 20 years ago would not have happened without it. LED lighting, and improvements in HVAC all came from the Energy Star program from the DOE. The guy that runs it drives me crazy but there is no denying the results. It continues to be funded because reducing our energy consumption is a part of our national security.

The methods I use for air tightening and insulating my buildings are born out of building science work from engineers funded by the Canadian government in the 50s and 60s. It is not new. What is new is the push to develop products to make it possible for anyone with minimal training to install. There-in lies the rub. in tests that I have witnessed at the Jake Pickle research center here in Austin, the fluid applied have not held up well and that isn't even the problem I have with them. They are not an answer for me. When I have sat down with the manufacturers,(not salesmen but it is hard to tell these days) I have 5-6 questions that I ask them. They can't answer them because the questions relate to the weaknesses in their products. The best fluid applied membranes still haven't addressed the problems and they cost 1$ a square foot for the material plus labor. Martin's article form 2010 states a cost of 60-65 cents installed but that isn't true at the recommended application thickness and if you find an applicator that even knows what a wet mil thickness gauge is I will be surprised.

I will ask Martin if he still agrees with what he wrote in 2010 about fluid applied membranes but I tested and rejected those several times over the last 15 years. Martin is no dummy but he is also wrong on a regular basis and sometimes when he is wrong he does a great disservice to the industry because of his stubbornness and his ability to get his message out to the public.

In my opinion, none of the latest generation of WRB systems will have as many problems as the Zipwall system. I look at installs all around me and none of them are installed correctly and when installed correctly they don't hold up well in the testing that I have personally laid eyes on. They are used because of cost and the people installing them are not properly trained. Tapes and goops and sealant caulks are all limited by two things, original application expertise and longevity. I don't trust any of them in showers or on walls but at least caulks can be maintained. When the tape falls off of your zip system or the nail holes swell from moisture intrusion or any of the other failures we see happen behind your cladding, you won't know until the damage is bad enough to show itself and by then it will be too late.

No system is perfect. The mod bit membranes I use can fish mouth and I recognize that it just a glorified tape that I cover my buildings with but testing and historical data over decades shows that it is very durable and I seldom use it as the only thing that keeps water out of the building. It is usually the third layer of defense and will never even see water. The buildings test at around .75 ACH50 and to improve on that requires more expensive windows and exhaust vent dampers. Minor air leakage at windows and backdraft dampers is not a problem for durability, indoor air quality or energy efficiency so I will accept it.

I am guilty of taking this thread off topic but the question asked in the first post deserves better than a yes or no answer and some of the responses I read are worrisome to me. I need to let it go and remember I came to this site to learn about my tractor and not to correct misconceptions about building performance and building systems. I do enough of that in my day job. I will TRY to refrain from becoming a POV warrior. My building science friends would laugh and roll their eyes if they knew I was typing posts about this stuff on the tractor website. I'm rolling my eyes at myself. Have a great weekend y'all. Mine looks to be too rainy to work on the tractor so I'm glad I got some clearing done yesterday after work. Grow grass grow.

 

[EddieWalker]

Not to be argumentative, but to add to my previous post about insulating a house. Wind is the enemy of the walls. There are millions of houses that do not have any wall insulation in them at all, but are kept at a reasonable temperature because they have good ceiling insulation and the walls are wind proof. The one I'm working on right now was built in the 50's and is a perfect example of this. I'm replacing all the windows on it and will be repainting it. There are a few issues with it that I'll be addressing, but the owners do not feel that there is any need to add exterior wall insulation to it since their electric bill isn't that high, and the cost of the insulation would be significant.

I'm not suggesting to not insulate the walls, but it's not as big of a deal as maxing out your R value in the attic area. Heat goes up, cold goes down, wind goes sideways. This is why windows do not cause a lot of loss to the interior envelope of a house, but skylights do. A good window gives you a R3 value in the middle of a R13 or 19 wall, and if you had the same on a skylight, you put R3 in the middle of R30 to R60, which is basically a huge hole in the middle of your barrier to keep heat and cold where you want it.

Since we are on walls, stopping the wind is your main goal. As mentioned, a lot of the tapes out there have failed on house wrap applications. What isn't mentioned is that the tape kept the house wrap in place while the sheeting went up and the house wrap and tape was never affected after it failed. It's not like the house wrap just fell off of the wall, it's still there doing its job. I've never seen flashing tape fail around windows, but wont say it's never happened. In most houses there is no flashing tape used at all. If you walk through a new housing development of any price range, it's very rare to see crews installing anything around the windows. Just a couple of nails and they are off to the next one. It's all about speed for them. This is where most issues occur in heat and cooling loss. This is where I find the mold and where I find rot most often other then bathrooms and kitchens where there are water and drain lines.

Back in the 90's SFO Airport lost a lawsuit about noise and had to pay to install 4 pane windows in all the houses affected by the increase of noise when they expanded the number of planes using the airport. One of my friends was one of the people that got the new windows. They did a good job of cutting down the noise, but didn't make any difference in what he paid to heat his house. He didn't have AC, just gas wall heaters on each floor, which is common there.

There are lots of ways to make it better, but just like adding NASCAR technology and parts to your car, it really wont make it any better for what you pay for those improvements. There is a point where you are doing it just to make yourself feel better.

 

[RayfromTX]

My 4,000 square foot home is net zero. I use between 500 and 600$ per year worth of electricity for total heating and cooling with a 13.4 SEER heat pump. I maintain a 73 degree set point on 100 degree days with 2 1/2 tons of AC with 50% run times in the hottest part of the day. .76 ACH50, unvented attic, Cardinal 366 glass, R13 walls, R30 roof. The slab isn't insulated but that would be the next thing that I would have done if I had trusted Termidor as much then as I do now. The house is 14 years old. During the winter ~1/3 of my heat loss is through the slab. I have kept the 8,000 sq foot house I am currently building at 74 degrees on 100 degree days with a 28 year old 3 ton heat pump. The methods we use work and they are not cost prohibitive. You can check the cost of 2" polyiso for the walls and 4" polyiso for the roof by Atlas which is made near Dallas. You will probably find it cheaper than spray foam. Should we take this discussion to private message to stop the thread hijack or is it ok with the OP? I think he got his answer.

 

[RayfromTX]

One other thing for you to consider. Wind is not the only cause of air infiltration. Locating HVAC equipment in a vented attic creates a large negative pressure in the living space due to supply duct and equipment leakage and stack effect also plays a role.

 

[PILOON]

Back in my late teens I built a log cabin of about 1200 sq ft.
Logs were very well caulked with fair amount of windows.
Cathedral ceiling with 3" foil covered foam board and horrible cinder block foundation.
\Foundation is horrible cinder blocks with 3" wool between studs.

My present home, about 1200sq ft as well, actually next door, was built with 6" studded walls, tapped vapor barrier, 6" wool insulation and house wrap outside.
Ceiling is R 40 and vented attic. My basement is 2" foam on 8" poured concrete.

So now why is it that the old log cabin costs about $1200 in heating while the newer more modern one cast me $3000. to heat?

Another house I had (but did not build) is on the other side of the lake, about same size with only 2 X 4 studded walls crappy roof insulation (like 8" wool with 1-2 " air space only cost $1000/year to heat.
I doubt that it was 'house wrapped' nor did it have vapor barrier that I know of.
Shucks in -25 deg we'd turn off the heat when working there.
OK, this house faced the sun all day and was fairly sheltered from winds.

The main thing that I can attribute this house higher costs to is my very large windows that face the windy side, and they all have that LoE gas option.
At that I opted for cedar framing as wood does not conduct cold vs metal which will.
(OK. LOL, my wife wanted a BRIGHT house with BIG windows)

Think!
You build a tight house, great insulation and all modern specs then add huge COLD (no R value) glass to have bright and good vistas?

LOL, so we had a nice view but then the trees grew and we see nothing.
We can't cut them as city bylaws forbid that due to the environment, because the birdies like to sit on the dead branches and perhaps a bird or squirrel will want to build a nest in that now hollowed out rotted tree stump.
Yes, that is what they said!
So the order of the day is , don't ask, do it and shut up. (and save a permit fee for cutting a dead tree).
LOL, clean up the chain saw sawdust and make the evidence disappear. Mud and soil on a stump does fool them.

 

[LittleBill21]

My 4,000 square foot home is net zero. I use between 500 and 600$ per year worth of electricity for total heating and cooling with a 13.4 SEER heat pump. I maintain a 73 degree set point on 100 degree days with 2 1/2 tons of AC with 50% run times in the hottest part of the day. .76 ACH50, unvented attic, Cardinal 366 glass, R13 walls, R30 roof. The slab isn't insulated but that would be the next thing that I would have done if I had trusted Termidor as much then as I do now. The house is 14 years old. During the winter ~1/3 of my heat loss is through the slab. I have kept the 8,000 sq foot house I am currently building at 74 degrees on 100 degree days with a 28 year old 3 ton heat pump. The methods we use work and they are not cost prohibitive. You can check the cost of 2" polyiso for the walls and 4" polyiso for the roof by Atlas which is made near Dallas. You will probably find it cheaper than spray foam. Should we take this discussion to private message to stop the thread hijack or is it ok with the OP? I think he got his answer.

i am new to insulation, and live in northeast pa, you don't like membranes, can you dumb down what design you would use for something like this, and i mean all the layers from the outside to the inside and the actual products you recommend

both for above and below ground walls please.

 

[RayfromTX]

i am new to insulation, and live in northeast pa, you don't like membranes, can you dumb down what design you would use for something like this, and i mean all the layers from the outside to the inside and the actual products you recommend

both for above and below ground walls please.

What would you use for your exterior cladding? What would you use for your interior finish surface? What will you use for your roofing material? What type of foundation will you use? What is your actual (from nws records) average January temperature and average August temperature? I can give you an answer after knowing those things. I can also give you a more generalized non specific answer without that info if you prefer. I'm headed for bed so I'll check back tomorrow.

Cheers

 

[LittleBill21]

What would you use for your exterior cladding? What would you use for your interior finish surface? What will you use for your roofing material? What type of foundation will you use? What is your actual (from nws records) average January temperature and average August temperature? I can give you an answer after knowing those things. I can also give you a more generalized non specific answer without that info if you prefer. I'm headed for bed so I'll check back tomorrow.

Cheers

weather for my area
Average Weather in Clarks Summit, Pennsylvania, United States, Year Round - Weather Spark

for existing building

2 story barn bottom insulated no heat in up or lower asphalt shingle roof

walls are rough cut lumber with actual 1 inch gaps between them, inside is osb board, walls are currently filled with blown insulation, plan to use vinyl siding, floor is concrete, there is a dampness in the lower section, 2 windows neither are open.

other is 1970 ranch cinder block half below ground, brick outside/plaster inside is bare, concrete floor, just looking for reccomendations,

and finally for a new building

poured concrete floor, cinder block below ground and standard vinyl siding. and above ground standard build asphalt shingles

i appreciate anything you offer.

 

[RayfromTX]

New building

Use a 60 mil modified bitumen peel and stick membrane on exterior of basement walls and extending to roof line used as air and vapor control layer. All insulation applied to the exterior of the mod bit membrane. Below grade use 3" of expanded polystyrene. Above grade use 3" of polyisocyanurate board foam or 4" of Rockwool rockboard80. Apply furring strips to the exterior of the insulation and cover with drainage plane of your choice. Use vent screen and the bottom and top of the wall to provide a vented rain screen. Install siding over the drainage plane. You may use more insulation but it will not be absolutely necessary in my opinion.

Use pans below all windows with wicking strips to allow sealing of windows completely into mod bit membrane while allowing water to escape the pan to the exterior when the windows someday fail and begin to leak. Use head flashings above all windows with end dams to channel water to the exterior at top corners. Windows should be furred out to the outer plane of the insulation layer and should be argon filled and northern low-e.

On the roof install 5/8 roof decking and dry in with #30 felt. Install 6-8" of polyisocyanurate foam in 2 layers with seams staggered in both directions. Cover this with 1/2" or 5/8" decking secured with #10 screws and 3" washers designed for the purpose secured into the first layer of decking. There is not need to hit the rafters with these screws. Install shingles over an approved drainage plane. Use only sealed combustion furnaces and water heaters or all electric. Your attic will not ve vented and will be room temperature or 2 degrees above. Plan for using your attic as conditioned space but you will not need a ducted supply. Your HVAC will need to be downsized appropriately for the greatly reduced load.

Install timers on all exhaust fans and use them to remove moisture from cooking and bathing and in the laundry. Use an HRV for fresh air if needed depending on occupancy load and use patterns. Allow for supplementary dehumidification to be added if building use warrants a need for it. You will be able to run a bit higher humidity level in the winter than you are used to and you should let your window condensation be your guide. You will not need nor should you install a humidifier. This building will be airtight and will not run as dry in the winter as a leaky building does. There is no risk of condensation in your walls or attic with this system.