Is there a maximum R value for insulating

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

jjohnston

Well-Known Member
Joined
Aug 5, 2009
Messages
108
Reaction score
6
I have been looking around. I see that code for my area requires an R of 49 for ceiling and 19 for walls. I am just curious. Is there a maximum? If I have an R49 currently, could I bump it to R80, or R100? or is R60 really as high as you want to go?

And if there is a max, what is the reason? would it cause to much moisture, etc?
 
You have to look at cost benifit and keep in mind a really good double glased window will have an R value of 5 or 6 if you are lucky.
 
It rather depends on where you live.
In the very coldest places 10 inches of polystyrene, more than that and you cannot measure any improvement.
 
Personally I think building codes are a total joke.

No outside wall IMO should ever be 6 freaking inches thick, every outer wall should be at least 12" thick and minimum R30+ as far as I am concerned.
Attic insulation IMO should be no less than R80.

"code" where I live which is in NC and in Climate Zone 4 is R15 for walls and R38 for Attic.
Sadly nothing I can do about my walls because like everyone else they are paper thin and frankly I seriously doubt actually have R15, my bet is R10 when it was built in 1984 and now that cheap fiber board insulation I am sure is less than R10.
My attic originally "was" R38 blown in pink manure but after squirrels got in there and stomped it all down and just age my bet is about R20.
A few years ago I added R38 "EcoBatt" on top of what is probably about R20 old insulation for something close to R60 in my attic which to me is absolutely dead minimum.
http://www.ecobatt.us/eco_batt.html

Made a big difference in how our upstairs bedroom felt in the Summer, the AC ran A LOT less and just felt more comfortable.

The more insulated the house, the less it cost to heat and cool, the quieter it is inside.
Building code should be DOUBLE+ what it currently is IMO.
 
Yep, but what percentage of builders "exceed" any code of any kind?

I would say roughly about 2% at best.

If you are designing and having a house built from scratch thats a bit different but even then I bet 90% of everyone sticks pretty close to code.

IF code were DOUBLE what it is now then all houses would be far more efficient AND the cost would be minimal because EVERYBODY would be doing it thus material cost would reflect the demand for the different sizes needed and become standard.

It is pretty rare to see a house that has 12"+ thick walls, there are some "Green" designs that do and they are usually small houses less than 1200sq/ft and set up for Solar power.

Personally I believe that all new homes should be built with Solar Panels, 1 small Wind Turbine, a Hydrogen Electrolyzer a system to collect rainwater for it & 1000 gallon tank like a propane tank to hold the Hydrogen so you can use it to run your car, lawn mower, other vehicles & equipment and some appliances.
This way everyone could be energy self reliant but still be connected to a grid so that excess energy can be stored and shared.
If this were code then it would add very minimal cost to a new home, would easily pay for itself in no time because your electric bill and gas bill would be virtually non existent.
That would save the average homeowner probably between $4000-$6000+ every year.
 
Do you think govt and the energy companies would ever allow that to happen. Look at all the lost tax revenue the would occur. It's not about energy efficiency or independence, it's about money and who gets to keep it.
 
Just personal opinions based of fictitious "R-value" numbers. Codes are just minimums that can be written for simplistic enforcement. The only people happy are the "pink panther" and similar companies.

Anybody with a bit of common sense can recognize the folly of excess when it comes to trying to be proper.

You can always follow the same simplistic logic and over-do the insulation. You will reach the point of diminishing returns economically and possibly create some very troublesome effects with moisture and air quality.

The "green" approaches are very entertaining and remind me of a scientist that is turned loose with a big, thick catalog that has a lot of great products and then tries to make them work together in a practical manner.

$6000/year savings per month like a $500/month and paying for the excess on a practical amortization schedule.

There are some basic things to do using traditional materials and methods, but using them to their and your advantage.
 
Do you think govt and the energy companies would ever allow that to happen. Look at all the lost tax revenue the would occur. It's not about energy efficiency or independence, it's about money and who gets to keep it.

Sadly this is true
 
Definition of a window -

A glorified hole in a wall that will lose heat (no matter what kind of glass, gas or films are is used and probably have moisture and leakage problems because it has to be installed by a person.

Dick
 
Why not take government control to the logical extremes. All homes in the USA by law should only be built in the temperate area of the country below say the Mason Dickson line. All homes must be built below ground level and highly insulated. Homes have to be located within 3 miles of your work place removing all need for cars. Canada must be disbanded and the only usage will be for farming like wise all northern states. Southern states should only be used during winter months and travel into those states done by train. The comfort zone for humans has to be controlled and enlarged. Temps between 40 and 90 degrees no heating or cooling should be allowed. The government in order to make the world safe for the masses should regulate and control everything. Actually personal homes should be banned by the government. Most are to big for the number of people living in one. Large dorm type housing is much better. And why light a room for one person to read by when all that wasted light could allow many to read. TV should also only be allowed as a group device. If we did all these kinds of things and made more and more laws to force everyone to save energy what a wonderful world we would have.


Sent from my iPhone using Home Repair
 
I don't even spend 4k a year if you added up all my electric, gas and water. I am efficient and my house is only to code. If people would stop being wasteful it is easy to do.
 
:clap:Bud: that was a silly grin on your face you should have posted a selfy.


..................;).................


Growing up in the 50s and 60s back in the days when men were men and dad bought a lot and started building a house without a plan or an inspection. Every dad on the block was in some stage of building a house totally or doing some of the work and hiring some done. Everyone seemed to help each other out and some really nice tight homes were built on the street I grew up on. Then came the 70’s and 80’s and subdivisions started popping up just outside of town with sheathing only on the corners and built in a couple weeks by a crew, covered in aluminum. I remember dad watching and going see how they build them walls on the deck and have cold spots built in and look at those nail gun joints they are going to pull apart and on and on with what he didn’t like, and then he always finished up with “My God they are paying top dollar for that!” He didn’t make it into the 90’s and on but I know without a doubt the regulations would have drove him insane.

People used to want to support innovation and efficiency because it made sense. It was logical and it saved them money and kept them warmer in the winter and cooler in the summer. One example was the house Dad built had a Frank Lloyd Wright inspired flat roof. I’m sure he got the idea from Popular Science or some such magazine he was always reading. Our roof all summer held 3 to 4 inches of water. That evaporation sucked the heat right out of the house. In fall he would pull a plug and drain it off. I don’t know how that would go over today with the new codes.

Driving around town now those 60 and 70 year old owner built homes are still looking good and not much different than I remember as a kid. Dad was right about the slapped up houses as most are looking their age or have been redone or replaced by now.

As the typical homeowner is less and less informed and aware of what goes in a home I guess more and more code is needed to protect them from their lack of knowledge. The reason why only 2% of the builders might exceed code is cost. People only look at surfaces anymore and most don’t care what’s inside the walls.

If I wanted a super insulated house I would go minimal on windows and I don’t think I would go thicker just to get more of the same insulation I think I would go with one of the foam over frame type designs.
 
There are windows that give about a R14 insulation (for center of glass) and up to about R9 for overall insulation BTW.

http://www.alpenhpp.com/wp-content/uploads/2014/02/925-Series-Datasheet-20140203-web.pdf

You can also add an extra R1.8 using "Indows".

http://www.indowwindows.com/storm-window-inserts/

Then finish that off with Thermal Insulated Shades which can add approx another R4+ and theoretically you can achieve at least an overall R value of R15 windows, which is about what most outer walls are in the US.

http://www.1windowquilts.com/products/full_broch.htm

So not impossible but the window will always be the weak link no matter what.
With proper "Passive" building techniques you can achieve an overall net Zero or even Net Positive energy consumption.
Net Zero is pretty commonplace right now.

After all the main reason for even discussing "R values" of anything is basically 2 fold, Comfort and Energy savings.
If you build a Net Zero or especially a Net Positive home then whatever your Rvalue is basically moot.
Although you can rest assured any Net Zero+ home will have high R values on everything, probably thermal mass walls and passive, plus have Solar or some other form of power production.

My wife and I are moving to Oregon as soon as we can sell our house in NC.

We plan on building as close to Net Zero as we can.

http://www.zerohomes.org/zero-homes-oregon/
 
Back
Top