Anyone use or explore precast concrete in residential construction?
Reaffirming that the “perfect wall” will have high thermal performance, not provide substrate for mold/decay organisms, provide exceptional strength (tornado/huricane/ falling trees and even ballistic resistant preferred) and be durable for a century or two, brings me to some form of insulated masonry (I am all ears if someone has another cost effective suggestion that fulfills said criteria). While comparing and contrasting ICF vs. some form of insulated CMU, I came across precast. I first looked at precast as I was comparing poured reinforced concrete floors for the decking of the structure (like a Quad-Deck, Insul-Deck). In an effort to achieve similar results with more convenience, possible less cost, precast flooring panels like a hollow core panel you drop in place with a crane are of interest: http://www.oldcastleprecast.com/products/buildingstructures/buildingcomponents/Pages/HollowcorePlank.aspx
In the same vein, there are high performing sandwich wall panels, exterior/interior cement with internal EPS/XPS of varying thickness and thermal value up to R-30. They account for thermal bridging to some degree with use of low thermal conductivity high strength carbon fiber and a welded wire fabric or C-GRID¯ carbon fiber mesh. Its like a reversed ICF wall without the need to shotcrete in the field. As some would say, it puts the foam where it belongs, in the middle of the wall. Its also amenable to adding additonal interior insulation with facility without the concern for creating the dreaded double vapor barrier given its cement/EPS construction.
http://www.highconcrete.com/products/Components/structural/CarbonCast-High-Performance-Insulated-Wall-Panels.cfm
Such a panel that would span from footing to roof-line, with an already finished exterior, sounds like it might be a good option (given transportation & production costs are not prohibitive, might have to be local). An interesting write up:
http://www.pci.org/view_file.cfm?file=JL-05-MAY-JUNE-3.pdf
Caveat emptor, its sponsored by the Precast Concrete Institute and a bit dated.
Has anyone else used or considered this form of building solution?
What are some of your thoughts/criticsms/comments?
Thanks for any input.
Happy 4th
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
"Reaffirming that the "perfect wall" will have high thermal performance, not provide substrate for mold/decay organisms, provide exceptional strength (tornado/huricane/ falling trees and even ballistic resistant preferred) and be durable for a century or two, brings me to some form of insulated masonry."
Precast concrete panels have been used for residential construction for at least six decades, mostly for low-cost multi-story mass housing. The performance characteristics in the areas you suggest have not been stellar (Google 'Ronan Point'). It would certainly be possible to use the material for high-performance single-family homes but the costs would likely be much higher than conventional construction with the additional disadvantage of being much harder to modify and upgrade either during construction or in the future as needs change over time. Probably the only performance criterion of those listed above that is hard to achieve more cost-effectively in a wood-framed building is tornado resistance: even there, as with falling trees, the roof of a concrete-walled building is still vulnerable.
Superior Walls makes a residential precast product. Used mostly for basement applications, they can also be used above-grade.
Two other companies have had some success with single family residential precast construction. The first is Royal Concrete Concepts out of Florida. Here is their website: http://www.royalconcreteconcepts.com/
{Note: In looking for their site, I noticed it is not up and running. Their Facebook page has not had an entry in almost 2 years. Apparently, Metromont bought them in 2011. Looks like they might have shuttered that business. Too bad, as they had a modular concrete system that could be used for any residential, municipal and/or light commercial application. It was a very well thought out system, complete with wiring and electrical boxes/switches, windows and doors pre-installed.}
The other is DuKane Precast out of Naperville, IL. You can read more about them here: http://www.dukaneprecast.com/
Also of note: There is a national production builder (who is at the very forefront of energy efficiency) that is currently testing an above-grade precast concrete wall system for their homes. I don't think they've gone public with the information yet, so I'm not going to divulge any more here.
James is correct that alterations/modifications are going to be a pain in the... rear, but I'll disagree with him on the cost side. The gap isn't nearly what people think. To further back my statement, this isn't the first time a national builder has taken a serious look at above-grade precast construction. (Another one, about 10 years ago, understandably couldn't get precast to equal their 2x4 price, so they gave up.) For those who are offering a slightly higher-end production product, or a custom product, I think the financials can very much be in order.
A similar method worth thinking about is tilt-up construction. http://en.wikipedia.org/wiki/Tilt_up
Lombardo,
We actually live in a pre-cast concrete house. It was built with panels similar to the Superior walls but they are taller. Our house is a single story with a walk-out basement. We used panels that were about 21' tall with a foam insulation "built in" to the panels. On top of that we added a 2x4 stud wall on the interior with blown cellulose insulation to increase the R-value.
Our walls are about R-40, the roof (14" combination of spray open-cell foam and blown cellulose) is R-60 and the basement is R-20 (EPS under the concrete slab). The house has been certified by the Passive House Institute of the US and meets all passive house standards.
Our monthly electric bill averages under $100. We are using a GSHP for heating/cooling, have a HPWH for the hot water (boosted slightly by the desuperheater on the GSHP) and have installed low-energy light bulbs. For cooking we use propane along with a convection microwave. We are slightly southwest of Raleigh North Carolina to give you an idea about our climate. The walls are manufactured by Ideal Precast in Durham and trucked to the building site - our walls were installed in about two days (one slight delay due to a T-storm that caused crane operator to set panel back on trailer in haste to avoid lightning strike and he flexed the panel causing it to crack). We've been in the house for just over a year now and really like the concrete construction. It adds to the sound reduction qualities and we feel very safe when high winds are about. The house is pretty large (about 4500sf heated space, including over 1200sf of basement "storage area") and we heat/cool the entire envelope - the "attic" space has ventilation to the rest of the house so we have no dead air spaces.
Our builder was Anchorage Building Corp of Chapel Hill and they have built several using this technique. Ideal Precast is the panel manufacturer, located near Raleigh Durham airport) and both have websites. I also blogged throughout the build should you care to read more - pittsboropassivhaus.blogspot.com is the address of the blog.
Cheers!