Insulating a cement block house?

Question

I have a new cement block house. I only want to insulate it from the OUTSIDE not the inside. Nothing I have found is good enough because either it requires re-caulking or could break or could mold, etc. I have decided that the only way to insulate it without maintenance is to build a cement wall to surround my house with an air pocket between the 2 walls as the insulation. The two walls cant mold or if they do it really does not matter or can be easily cured. My question is this......

What kind of R value do I get if my house is 8 inch cement block with......say..... a 4 or 6 inch air pocket with a 4 or 6 inch block wall as the outside? In other words, my 8 inch block wall would be surrounded by an air pocket held in by a second thinner block wall. HELP!

Answer 1

virtually none. this is called a double masonry wall. people who have houses like this are filling that gap with spray in foam insulation.

Answer 2

OK . . not an expert here but let us reason this together . . . if you put a second block wall outside of your home and you will be creating an air space that has poor air circulation which means STALE AIR . . . dirt, dust, mold, bugs, spiders, mites all the small yucky stuff will eventually be there . . . think a basement or attic noone has been in for years . . . '
Also . . . concrete walls have always been a wick for moisture . .
Provided the bottom foot to foot & half of the exterior of the house is sealed bottom and sides from the earth - drilling and filling the blocks with insulation should be sufficient . . . NOT however with expandable foam . . . the stuff can & will bust a concrete block if it does not have space to expand. The recycled paper stuff might not be the right filler either . . . moisture again.
Keep in mind the types of gasses or by-products each type of potential filler may give off: both initially and over a period of time.
Your home is your lifetime investment and the health of yourself and your family comes first.
You could also consider use of a sealed {glass- glass type} porch on the appropiate end of the house with solar panels or use of solar panels &/or skylights for heating. There are many 'green' ways to heat and cool your home that would be cost efficient safe for your family. AND think how cool you will be . . . a hero helping to save the earth in your own way.

Answer 3

Here is your first problem. To build another wall around the first one will require a building permit. Another footings with steel going 4 feet up and it is to be grouted(concrete poured down the holes) If this sounds like your best idea then by all means go on. But I may have solution for you. Try using firing strips of 2"x2" every 16" on center (use redwood) Now place solid foam in between this for insulation. Then use siding there is a product called hardi backer it is a concrete based product and it is paintable. Best of luck with your project.

Answer 4

If you want to put up a poured wall use the concrete forms that are made out of styrofoam. You stack them up like blocks and then pour in your concrete and then you just leave them in place. This gives you added R value and the blocks also have kind of a furring strip built in so you can put on siding..

Answer 5

if its a new house why didnt you think of this when it was being built? you could have had styrofoam inserts placed in the core of the blocks before they were laid...you could have had them filled with vermiculite after they were laid...your best recouse now would be to have dry-vit done to the exterior walls...good insulating properties and better looking than plain block walls...