We are in the initial steps of building our retirement home. We have our initial meeting with an architect after the first of the year. Before hand I have been making a list of questions, of which I have MANY.
Preliminary Details as follows.... Northeast (Ct), Semi Rural, 3 Bedroom, 2 and 1/2 Bath, Approx 1500 Sq Ft, Dimensions (May Change a bit) 24x40 with 12x40 on the second level for visitors...... Enough of this, you should get the general picture!
My question concerns insulation... Im started to do a bit of research (on the web) and quickly became TOTALLY confused...... Open cell and closed cell foam, single wall vs double wall, Blue Board, Ty=Wrap, Fiber Glass......
What I want (I think) is a well insulated home, draft free, and warm for the cold winter months (NO, I am NOT a Snowbird).... Cost is a factor, but can someone suggest some info for a NON-Techno individual?
In other words, what would you use?
Thanks for your time. I am sure that I will be back with more questions as get deeper into this project.
Thanks Again, Razu
I just joined the forum because I saw your question, and I hope I can be of help. Insulation can be a very confusing topic, everyone has the best insulation, right? It's great that you are meeting with an architect. I would go armed with the idea that you want to build a high performance home. This is a catch all term that includes everything you need to get an energy efficient, comfortable home with good indoor air quality.
Regarding the specifics on insulation.
My #1 recommendation is mineral wool, also known as rock wool. It is fireproof, water-resistant (like a duck), non-toxic, available in batt and board form, it does not sag or shrink, and it is easy to install. It is great for walls and roofs.
If you have a slab, I would recommend underslab insulation in your climate, for this you will need foam. Foam is not at the top of my list of favorites, but there are some applications where it is the only option and this is one.
If you go with an unvented roof deck you will need to be attentive to the code. I believe the IRC 2012 section is 806.5 2012 IRC 806.5.
As I mentioned, foam is not my favorite. My gripe about spray foam is that it is toxic when installed (jury is out on long term), it is flammable, it must be installed by a professional, it 'ain't cheap' and it shrinks.
A lot of the advertising for apray foam has to do with the superior insulation quality. Open cell foam has an R-value per inch similar to fiberglass and mineral wool. Closed cell has a much higher R-per inch, average about 6. The reason that energy performance tends to be great with spray foam is because it does the double duty of air sealing. In both open and closed cell R-38 is R-38, not a magical higher number. It is the air sealing that helps the insulation perform at its peak level.
Air sealing is critical in a high performance home. Instead of spray foam, an alternative system has been developed by both Knauf and Owens Corning. Essentially it is a latex spray to seal all the cracks.
Weather resistive barriers are part of your air sealing strategy, and I would look to a liquid applied instead of fabric. There are many manufacturers that make a liquid applied. Tyvek makes one, as does prosoco.
It's best to get as much insulation as you can afford. When you get into superinsulation levels you can begin to see real savings in energy use.
An air tight home needs good ventilation. Balanced ventilation can be provided by an ERV or HRV. The higher performing models will save money over time. Zehnder and Ultimate aire make high performance HRV's. Excellent indoor air quality is a side benefit of using an HRV or ERV. This is because they have great filters and constantly supply your home with fresh air.
Other insulation options to look at are formaldehyde free blown in batt/blanket systems. Knauf and Johns Manville are two manufacturers.
Some folks like cellulose because is provides good air sealing like spray foam. I'm not such a fan because my newspaper makes me sneeze. I would be wary of living in a whole house of it. That's my personal feeling about it, but otherwise people have reported positive results.
I could go on and on, but one last comment. Make sure to have a good moisture management system and let your assemblies (walls, roof, floor) dry to one side or the other, moisture can get caught in building assemblies which is not good! Making your home durable, comfortable and energy efficient certainly takes some extra attention, but if you feel it's valuable it's worth doing.
LaurieThis message has been edited. Last edited by: laurie@modernhouse-plans,
We are planning a large garage addition. Six inch stud walls instead of 2x4 to make more room for better wall insulation. Tyvek for sure, to keep out drafts/wind. I really like/prefer fiberglass bat insulation over rock wool. It can be scratchy to install, but less dusty too.
On a home, try to put as much insulation as you can, the upper limits of what is recommended for your climate/zip code. I doubt heating costs are ever going to go down, so keeping that expensive heat (or cold in air conditioning) inside, would be a dollar smart solution when building. Payback is well worth every dollar spent on insulation, in my opinion.
And as mentioned, enough attic ventilation as well as some fresh air exchange in the home is necessary for every thing to work well, and for house comfort.