COVINTEC construction experiences?

[costaricabuilder]

The Covintec system sounds great and makes sense on paper but here in CR all the input I have received from contractors who have used the system over the last 10 years has been negative. I am looking for some positive input as this product makes a lot of sense with the advent of "Green Home Building".
This construction system from Mexico has been used for years and is a totally different method than typical concrete block and column construction. Because of the Covintec extruded polystyrene (EPS) panels energy efficiency there is now new interest as related to "Green Home Building". EPS foam products whether used for insulation or packaging are lightweight, versatile, sanitary, energy efficient, and most of all cost effective. The manufacture of EPS foam uses less energy than that used in the manufacture of paper based alternatives. According to The Midwest Research Institute study on special packaging applications, the total energy requirements to make plastic containers (including both processing and materials energy) were lower than or equal to the energy consumed to make competing materials. Covintec is a building system that replaces traditional block, column, and beam construction.

Covintec comes in 4-foot-by-8-foot panels of steel wire mesh that surrounds expanded polystyrene, which is then covered with traditional plaster. Benefits include structural resistance to hurricane-force winds and earthquake activity; quick installation; great versatility (the panels can be used in a wide array of architectural styles); transportation cost savings because it weighs less than block; improved insulation that reduces noise from outside and between rooms; and protection from humidity damage. Plus, Covintec is relatively seismic-proof, and with eight times the thermal insulation of traditional block systems, tests have shown that it provides electric energy savings for homeowners of 23 percent to 27 percent. And because there's no wood and the panels are embedded with steel, bugs and critters can't eat it or chew through it to live inside.

[Ivo]

Hi Tom
Thanx for your input on the forum. About 18 years ago, I have seen it used a lot in construction in Mexico and Guatemala, they even did staircases and 20 story buildings with it. I thought it was an awesome material and I tried to bring it to Costa Rica. We did some trials with it here in Costa Rica and it turned out that the river sand is not fine enough and gets stuck in the nozzles of the spraygun when doing the "repello" concrete finish. We tried making bigger nozzles but didn't work. Years later, a developer in Heredia brought the same system from Mexico and started building a low income development with it. A year later the complaints started: the rats were eating through the walls. They had the same problems we were having with the concrete finish and probably left parts of the styrofoam uncovered and the rats loved it. This issue was all over the newspapers back then. About 6 years ago, several importers started bringing in the system again and now do the concrete finish they do as they do with the concrete blocks, by hand. I have seen it used a lot in apartment buildings now and a lot on exterior design like the front of the Banco Cuscatlan right next to Lacsa in La Uruca. That's all Covintec. So apparently, it works well. I don't know what humidity does to the styrofoam over the years, but just like drywall, most local buyers once they find out what it is and they can choose between a house built in concrete block or in Covintec, you may guess which one they'll buy.....
Hope this helps

[Russ]

I looked into these panels about 8 years ago.  At that time the panels were more expensive than concrete blocks, although clearly they are faster so the idea was that you could save on labor costs.  But I am not sure how "green" they can be, since the foam is petroleum based, right? Unless it was made from recycled plastics... Anyway, I decided against using the panels because I felt that the it would be worth it to pay the extra hours of work and get something that was more substantial, particularly on the exterior walls.  In my area we don't need heat or air conditioning, so the insulation capabilities were not a factor.  However this could work well for creating unusual facades, because of the light weight and might turn out to be better than gypsum for interior walls.

An alternative system that I have seen recently that I really liked are the "super" blocks.  These are similar to cinder blocks, but each block is 3 times as long as a regular block.  You submit your design to the company and they will calculate the materials needed.  It is faster, because the blocks go on top of one another rather than being staggered.  Also you may buy the re-bar already shaped into columns for the walls and also for the foundation below the walls.  The blocks are 30% more costly than regular blocks, but the re-bar for the columns is the same price.  In addition, you save money on the mortar that would go between the sides of each block.  According to the sales rep, there is a 30% savings overall when compared to building with regular block and yet you get the same (or better) benefits as to security, anti-seismic qualities, durability and quality.

[marr]

Good evening, I was very pleased to see your information about Covintec. I have also heard of another low cost house building system called Habicon. Apparently Habitat for Humanity uses it for there house builds. As well the system is manufactured in Cartago. If you you have heard about it or know where I would appreciate hearing from you.

Thanks Dan