Product Comparison

Highly Insulating          Top

(ICFs: Insulated Concrete Forms) are generally some variation of polystyrene panels held together by steel or plastic ties. The panels are designed to fit together in such a way that a space is left between them for concrete. Drywall is usually attached by screwing into plastic strips imbedded into the interior face of the wall, or by "furring out" a secondary interior wall. Stucco is adhered to the exterior by attaching wire mesh.

Ready For Stucco          Top

The exterior surface of Tech Blocks is designed to immediately accept stucco without the need for wire mesh.  (Independent tests have shown that stucco bonds directly to the surface of Tech Blocks at least 3 times stronger than the bond achieved using the traditional wire mesh approach to stucco attachment.)  CMU blocks are comparable to Tech Blocks in this regard, but wood frame walls need at the very least the application of wire mesh that has building paper attached to it.  More often polystyrene, plywood, AIS board, or OSB panels are first nailed to the studs to act as backing for the stucco and wire mesh.  Foam forms require wire mesh, and some jurisdictions mandate that special kinds of stucco be used on foam, which adds to cost.

The simple addition of brick ties placed between the Tech Blocks during stacking is all that is needed to prepare the wall for masonry- based stone or brick veneer.

Ready For Drywall          Top

Both Tech Block and wood frame walls are ready for drywall installation immediately  upon erection.  CMU block walls need to be "furred out", which is the process of  attaching wood strips to the blocks as an attachment surface for drywall.

ICFs claim to be ready for drywall, but this is somewhat misleading in that there are  many areas in the typical home where the ICF foam walls need to be enhanced  before other items can be attached to them.  The installation into foam of backing for  items like kitchen cabinets, interior walls, shelving, towel racks, bath tubs, shower  stalls, or fire blocking is problematical with ICFs.  This is one of the biggest  weaknesses with these types of walls. 

Waterproof          Top

When Tech Blocks are used under ground it is without the OSB layer.  The block is then impervious to moisture and will not promote the growth of mildew or rot.  Both CMU and ICFs are comparable in this regard, but wood frame construction is susceptible to dry rot which results from moisture permeating the wall.  There are currently hundreds of thousands of wood frame homes in the southeastern United States that are falling to pieces due to water vapor being trapped behind synthetic stucco, as was reported on the 20/20 TV news program in July 1999.

A Tech Block wall is stuccoed right down to the footing which, when added to our waterproof block material, forms a solid barrier against water infiltration.

Termite Resistant          Top

The Tech Block Wall System is designed to be stuccoed right down to the footing.  This creates a a formidable barrier to termite infestation.  Both CMU and ICF walls match the Tech Block resistance to termites, but wood frame walls are notoriously susceptible to termites.

Fire Resistant          Top

We applied the flame of a cutting torch to our block material for two hours.  The block material did not burn and there was no discernible rise in temperature on the other side of the block.  The polystyrene insulation in Tech Blocks is encased in cement which inhibits melting.  Further, the strength of our walls is dependent on the concrete and steel that is inside the block channels, so our walls may be blackened by fire but will remain standing and structurally sound.

The OSB layer on the interior surface of Tech Block is sandwiched in between block material and drywall in a finished wall.  The drywall has a half hour fire rating and the sandwich design eliminates open spaces that support the traveling of fire through a wall.  CMU block construction, where the furring out of an interior attachment surface has been accomplished, cannot claim this.  Of course, wood frame walls will burn.  The foam panels in ICFs will melt, but they won't feed a fire and have good fire resistance because of this and their concrete cores.

Sound Resistant         Top

Sound is resisted in two ways:  It is reflected by hard surfaces, and it is absorbed by porous surfaces.  Tech Blocks, CMU blocks, and ICFs all have a combination of both surfaces and are all very sound resistant.  Wood frame walls, however, transmit sound fairly well and must be specially enhanced if sound resistance is a concern.

Easy To Erect          Top

When comparing the ease of construction of various wall systems, each system must be completed to the same stage in order to make a fair comparison.  For instance, framing wood stud walls is quick and easy, but it isn't the whole picture.  One would have to consider the installation of bracing, backing, fire blocking, batt insulation, foam panels, house wrap, and wire mesh to bring a wood frame wall to  the same stage that Tech Block achieves when it is initially installed.  When all of the components necessary to construct a completed wall are considered, it becomes evident that both wood stud walls and Tech Block walls can be described as moderately easy to erect.

CMU block and ICF construction, on the other hand, are both labor intensive.  Cinder block walls are held together with mortar joints, the installation of which is time consuming and requires specialized equipment and expertise.  ICF construction is even worse, due to the complex bracing needed and to the weakness of the foam form material itself.  Since foam forms cannot withstand the pressure of more than a few feet in height of grout, concrete trucks and grout pumps may have to be brought to the jobsite 4 or 5 times, which is not only expensive but results in cold joints inside the walls.  And let's face it -- when you're done, you're looking at foam.  Now you have to attach stucco to the outside and everything else to the inside, which creates a further catalogue of problems.  ICF construction is so user-unfriendly that many of the manufacturers have set up schools and training programs to help mitigate the situation.

Uses Concrete Efficiently          Top

Tech Blocks form a wall that contains within it an interconnecting steel-reinforced concrete gridwork.  This cage-like design gives our walls strength without having to use massive amounts of concrete, which is expensive and heavy.  Using more concrete requires more bracing during construction.  Also, for a given wall thickness, the more grout that is used the less room remains for insulation material (polystyrene).  ICF foam form systems use so much concrete that they usually must be poured in heights of less than 4' or the foam panels will fail to retain the concrete during the grouting process.

CMU wall construction rates the lowest in this category in the sense that the concrete blocks are individually mortared together and then grout is poured into some or all of the cells from the top of the wall.  This two stage process is extremely inefficient in terms of effort and expense (and the result is a wall with an R-factor of about 7).