4.1 INTERIOR/EXTERIOR FINISHES

Greenblock walls accept virtually any exterior or interior wall finish, from drywall to stucco to siding to stone. Our sub-surface furring strips, spaced on 6 inch centers, are clearly marked on the outside of each block allowing for easy, efficient attachments. Below are several examples...

VAPOR and AIR BARRIERS:

Greenblock walls do not require additional vapor barrier. The solid concrete core covered with the low permeance EPS (Type II) foam insulation on the inside wall face keeps water vapor from penetrating the wall.

The fact that the inner face of EPS foam maintains a similar temperature as the inside air of the building and that Greenblock walls have no cavity means that no condensation can occur within the wall assembly.

Greenblock walls do not require an air barrier (building wrap) layer as the solid concrete core and low permeance EPS (Type II) foam insulation on the outside wall face keeps air and moisture from penetrating the wall.

INTERIOR DRYWALL:

Drywall can be installed over a Greenblock wall in a similar manner to a stud wall, with the following time-saving exceptions:

• Greenblock plastic webs (furring strips) are located on 6” centers from floor to ceiling for easy attachment of any type of interior wall finish.
• The butt joints of the sheetrock do not need to fall on webs (studs) as the foam provides solid backing wherever the joints fall.
• A foam-compatible adhesive can be used to effectively fasten the sheetrock to the Greenblock wall along with screws. Always make sure to verify the local code for types and spacing for sheetrock fasteners. Typically, adhesive alone is not allowed as a fastener of sheetrock, but again check with local building codes. Many local building codes require the application of 1/2” drywall or other suitable thermal barrier in any living space even though the EPS foam has a fire retardant component. Always verify local building code requirements.

Non-habitable spaces such as crawl spaces, attics, and other types of hidden areas typically do not require a thermal barrier (drywall).

Embedded furring tabs are fixed at each corner of the Greenblock 90° corner forms for solid sheetrock fastening at all corners

EXTERIOR FINISHES:

Siding material of some kind must be installed over the EPS foam to protect it from the UV rays of the sun. Foam left exposed to the sun will degrade on the exposed surface by slowly breaking and getting “dusty”.

Metal and vinyl siding can be installed directly over the top of the EPS.

Although air guns can be used, Greenblock recommends the use of screw guns when attaching exterior siding. Always follow manufacturer’s recommendations and local codes to determine the size and spacing of fasteners for all siding products. Any type of siding that is used on a typical wood-framed building can be used on a Greenblock building.

EIFS:

There are now acrylic-based stucco products available that are more flexible and easier to work with than traditional cement-based stucco. Collectively these products are known as EIFS (Exterior Insulation Finish Systems) and almost always require an EPS substrate.

Because Greenblock blocks are made with EPS, they are a natural fit for EIFS finishes. In addition, the Greenblock webs are embedded 1/2” beneath the surface of the EPS foam to comply with EIFS manufacturer requirements.

It is important to follow the EIFS manufacturer’s application procedures.

TRADITIONAL STUCCO:

Greenblock walls will accept traditional cement-based stucco product. Greenblock recommends a screw gun when attaching the wire lath mesh to the walls. Use screws with a wide head or screws along with washers to best hold the mesh in place.

Consult local building codes for vertical and horizontal fastener placement requirements. The center-to-center fastener spacing requirements for nails and staples must be followed for screws as well. Again, check with local codes for all specific requirements relating to the application of stucco over EPS insulation.

CEMENT COMPOSITE SIDING:

This type of siding can usually be fastened directly to the Greenblock webs. Greenblock recommends a screw gun to fasten flat-headed exterior screws. The screws pull the siding in tight and hold the siding securely in place. Some manufacturers may require the siding to be strapped out to allow air space behind. Vertical or shake patterns will require strapping for fastening. Always follow manufacturer’s recommendations and local codes to determine the size and spacing of fasteners for all siding products.

Check with your siding manufacturer for specific requirements.

BRICK VENEER:

Greenblock Brickledge forms are used to support a brick veneer as the exterior finish material. The Brick Ledge forms are simply placed at a level where the brick is desired to begin. The design of the form creates a reinforced concrete ledge.

To install Brick Ledge form units, follow the instructions on Section 3.24 of this manual.