Posted By Manfred on 01/06/2009 9:21 AM
 We use an average of 14 trees per house for the exterior structure of a house. Ouch! Even if only 400000 houses were build each year with lumber that would be how much? Is that not a Forest that is gone for 20-30 years?

Posted By aardvarcus on 01/01/2009 5:43 PM
I am not sure if you have ever seen a properly built stick frame house. I'm not talking the hunks of garbage you see a dime a dozen on streetcorners, I'm taking about drainage planes, metal storm ties, all screw construction, double plywood diaphragms, foam sheathing, timber framing, the whole nine yards. I find it a little unfair to lump all of one style of houses together. I am sure I could find a few ICF houses that weren't built properly, but it would be unfair to judge them all by those few. As far as energy efficiency, there have been and continue to be highly energy efficient houses built using stick framing. Just think spray foam, double stud, or foam sheathing.

I admit, masonry is much stronger, which is why I like to wrap my wood frames with a brick/stone cover. However, the exterior of an ICF house is not masonry, it is foam. In a fire or extreme weather event, even if the concrete core remained solid, the outer foam would be completely demolished and torn to bits. If you want to have a truly solid house, put your masonry outside your foam, not vise versa. You also have to consider that unless you build a monolithic dome, your roof isn't going to be masonry, and will be susceptible to damage. What good will it do if after a storm you come back to nothing but solid concrete walls, with the roof gone, insides destroyed, and the foam covering blown away?

It's not that I dislike ICF's, I just don't buy into the idea of blindly following the current trend and writing off everything else as a hunk of garbage. I believe there are many ways and styles of properly building a house, and it is up to each person to decide for themselves how they want to approach it.

Posted By gregj on 01/13/2009 1:17 PM


There are certainly many pros and cons to consider in the lumber vs concrete house debate but I don't think you can pull out the green card and use it against lumber and for concrete.

I think it has been pretty well established that the process required to manufacture cement creates a huge amount of greenhouse gases. Using lumber promotes responsible stewardship of private forests because their use as lumber gives these forests financial value. These forests actually consume greenhouse gases (CO2) and sequester the CO2 within the growing trees as well as the final lumber. So lumber use reduces greenhouse gases and keeps it tied up until the lumber is burned or rots. In a well built structure that should not occur for a very long time.

I respectfully disagree.  The longevity of concrete products or in this case concrete homes, makes them quite "green". 


As it stands today the cement industry by itself emits 5% of the total CO2 emissions for the entire earth. If we switched all house construction from lumber to concrete what would that number skyrocket to????

Posted By gregj on 01/13/2009 3:39 PM

Posted By aardvarcus on 01/13/2009 7:28 PM
About the green factor-
99.99% of the wood you buy today isn't from slashed old growth forests. Using lots of wood from managed forests is actually eco-friendly. Undisturbed forests are carbon neutral, because as trees die they fall, rot, and re-release all the carbon they previously absorbed, with a net effect of nothing. However, if you keep the wood from rotting and replant a new tree, you will have a net carbon absorption. And what better way to keep the wood from rotting than to build a house with it?
Also, just do a search on concrete and the environment. It is one of the WORST materials we use today. I am not saying we shouldn't use it, as I plan on using quite a bit of it in my next house, but don't act like it is eco-friendly.

and 87.5% of facts are made up on the spot. lol  JK. Concrete IS green, you guys need to do some research seriously.  Wood has it's place and yes managed forests are the way to go.  But a home built with concrete is a superior AND green home.


About structural strength- I admit a high quality properly installed concrete wall will be stronger than a high quality properly installed wood wall. But any old slapped together concrete wall will not stand up to a high quality wood wall.

What is concrete's biggest downfall? Tensile strength. The forces on a wall in a storm are very complex as the wind swirls in and around the house in different ways, making the walls attempt to twist, bend, and contort. You have to treat the wall like it is a beam, and for a concrete beam to handle the tensile forces, it must be reinforced with rebar. The rebar also needs to go where the forces are, which means outer and inner bars all throughout the walls, not just one slapped in the middle. If you do not put adequate rebar in the wall, it will crack or worse shear off.

You make a valid point but with ICF, rebar is a standard practice to greatly reduce this issue.  Also the ICF process of curing the concrete increases that strength to ROUGHLY 5000 psi, or more if desired.  Now show me a stick built wall that can equate that.  And thats my point.  If the big one comes unless you are in an abandoned nuclear silo a mile underground it won't matter what you live in.  But for the vast majority of things our homes encounter, concrete is a superior building product. 

Everyone has seen how stick framed houses today are. It's not the fault of the building material, it is the contractors who don't care. Every single corner that can be cut has, and some that can't be cut have been anyway. What do you think contractors will do when they start using ICFs? You won't be able to find a stick of rebar in the whole wall. You will also probably finding some quick set chemicals mixed in too. Any properly vibrated? Forget it.

Valid point.

Also, in any storm situation, the roof or roof attachment is going to be the first point of failure, not the wall. It doesn't matter if your wall can stand up to 100,000,000 MPH winds if your roof isn't strong enough to withstand it.

So how can anyone say that any old house built with ICF's is going to be stronger than my house just because my house uses wood in the walls? My rafters are 2*12's , and they are screwed into my 8*16 timbers and my load bearing ridge beam which is set into my solid masonry fireplace on one side and with solid wood down to the bond beam in the top of my basement wall on the other. Even though they aren't up to reinforced concrete standards, my double diaphragm 2*6 walls are incredible strong. Just because a house has concrete in the walls doesn't immediately make it structurally superior to every single wood framed house in existence.

What am I getting at? Its not the material, it is the Design and Proper Installation of the material that matters. There is no material that is foolproof, even concrete.

While there is no material that is totally foolproof, I think the OP was not stating that but that concrete is superior to wood.  Of course there are numerous variables to consider but if you had 2 houses built as they should be, 1 concrete and 1 wood; the concrete house will be a superior house.  Does it mean that the wood house is a bad home?  No, you could have a very nice energy efficient stick built home, but it will not equal the concrete home, which is better.  I'm a good looking guy, rather good looking in fact, but that doesn't mean that there are not other better looking guys out there.  I am your stick built home you described above.  lol 

Posted By ICFconstruction on 01/13/2009 8:26 PM
First off I don't give two craps about Al Gore, but he did invent wood and concrete.

Aardvarcus,

About the roof failing first from windstorm, not necessarily true. But if the walls go, the roof will. And a roof on a better wall will withstand a whole lot more.

We had two kids in the past three years die in MN tornadoes, both died when the wood framed walls and roof fell in on them. They would be alive it they had been in an ICF house!

Rykertest

Here is my reference, Show me yours:
http://www.wbcsdcement.org/pdf/tf1/prghgt42.pdf Cement industry emits 5% of C02 globally


So how much rainforest wood is used for framing houses in the US??? I've only seen North American sources for framing lumber. I'm not condoning rainforest destruction but to my knowledge there is no connection between house framing in the US and rainforest destruction.


I do live in a wonderful place and am quite calm. I just don't like it when people try to say building with lumber isn't green as an argument for concrete construction. I also like concrete construction and my next house will likely be ICF. But why bring up bogus arguments like the green issue. Those twisted studs sold as lumber today are new growth forests that are planted as fast as they are harvested and their growth and use is a net good for the environment. Cement is a great building material but it does have the very real negative consequence of CO2 emission that needs to be addressed.