Static structures (e.g. – buildings) – Wall – ceiling – floor – or roof designed for ventilation or... – Embedded flashing
Reexamination Certificate
1999-01-08
2001-10-16
Friedman, Carl D. (Department: 3635)
Static structures (e.g., buildings)
Wall, ceiling, floor, or roof designed for ventilation or...
Embedded flashing
C052S302700, C052S101000, C052S302100, C052S169500, C239S200000, C239S266000, C239S269000, C239S567000
Reexamination Certificate
active
06301849
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to stucco siding and trim on buildings, and more particularly, to a flashing article for sealing out and draining away moisture from stucco coated exterior wall surfaces, and for impeding the ingress of termites, rodents, and other animal infestation.
BACKGROUND OF THE INVENTION
There are three primary types of stucco systems commonly applied to exterior wall surfaces of buildings. Hard Coat Stucco has a wire mesh layer, a base coat of a concrete material (known as a “brown coat” or “scratch”), a finish coat of a similar composition as the base coat, and a coat of paint. Hard Coat is essentially the original stucco system that dates back several hundred years.
Exterior Insulation and Finishing System (known as “EIFS”) has an insulation layer, a base coat of a concrete material with a fabric mesh, and a synthetic finish coat with a concrete material and a latex color. EIFS was introduced in the 1950's to provide a synthetic stucco coat that is less prone to cracking and that eliminates the need for a coat of paint, and to also provide an easy-to-install exterior layer of insulation.
European Stucco has a wire mesh layer, a base coat of a concrete material (known as a “brown coat” or “scratch”), and a synthetic finish coat with a concrete material and a latex color. European Stucco thus combines a synthetic finish coat with a stucco base coat. There are also a number of variations and combinations of these basic stucco systems in use.
Traditionally, the layers and coatings comprising a stucco system were applied to the wall down to below ground level and overlapping with the foundation, thereby sealing out moisture, leaving no wooden wall surface exposed, and providing an attractive decorative appearance. Stucco tends to crack, however, which allows moisture into the wall, in addition to moisture seeping into the wall around windows, doors, and other joints. The moisture seeps downward within the wall due to gravity and capillary action, and because the stucco coating is applied to below ground level and overlaps the foundation forming a seal, the moisture gets trapped inside the lower wall. The trapped moisture promotes dry rot, parasitic fungi, mildew, and other decaying of the lower portion of the wood wall, and invites and often results in termite infestation.
One attempted solution to the moisture problem has been to change building codes to require that eight inches of exposed wall be left above grade and below the bottom of the stucco coating for new buildings. The purpose was to ensure that homeowners and/or pest control experts could inspect for and easily detect the presence of termites by their trails in the dirt adjacent the bottom of the wall.
Unfortunately, this does not address the underlying problem of moisture trapped in the wall. For buildings with a foundation thick enough that the stucco coating overlaps the foundation, any moisture will still be sealed inside the wall. For buildings with a thinner foundation, a strip of the wooden wall is left exposed to the elements, resulting in more damp decaying wood low in walls and providing easier access for termites, small rodents, and the like into the building.
This attempted solution is extremely problematic in areas of the country such as the South where many homes are built on concrete slabs of approximately six inches thickness or less that extend only slightly above ground level. An eight inch strip of wooden wall can be left exposed between the top of the slab at about ground level and the bottom of the stucco coating at about eight inches above ground level. The situation is even worse in many cases where the stucco coating bottom is more than eight inches above ground level and/or where the slab top is slightly below ground level due to undulation of the ground. Furthermore, this attempted solution is entirely unsuitable for retrofit applications where termites have already infested the wood, because removing the stucco from below ground level to about eight inches above ground level simply provides the termites with easier access to channel into the house.
One known article directed to the moisture problem provides a “U” bracket with the open side up for fitting over the stucco and foam insulation undercoating, with numerous closely spaced holes in the bottom of the “U” for drainage. The article is mounted to the wall on one side of the “U” to form a seal.
There are significant drawbacks to this article, including that it can only be properly installed with the initial application of the stucco during construction, and cannot be properly installed in retrofit applications where an existing building has stucco. This is because the “U” bracket cannot be inserted between the outer surface of the wall and the inner surface of the existing insulation without significantly damaging the insulation and stucco. Additionally, in order for moisture to escape the wall and properly drain into the “U” bracket, foam insulation with a vertically grooved back must be used. This further compounds the drawback for retrofit applications, because groove-backed foam insulation was not available for installation on homes until about the year 1997, so “U” bracket retrofitting on any home built prior to this often results in damaged stucco and insulation, and still does not provide sufficient moisture drainage from the wall to avoid the moisture and infestation problems described heretofore.
Another significant drawback to the “U” bracket article, especially in the South where concrete slabs are commonly employed as discussed heretofore, is that it does not cover or seal any exposed wall between the bottom of the stucco/bracket and ground level. Furthermore, the drain holes encourage moisture to drain vertically down from the bracket and thus moisture settles into the ground immediately adjacent the wall. Additionally, the numerous holes in the bracket provide termites an easy avenue into the building.
Another known system provides a polymeric/concrete layer from below the top of the foundation down to the soil grade line, with a termite shield in an open space against the wall at the top of the foundation and a decorative cover strip for the open space. The polymeric/concrete layer and termite shield act as a barrier to termite intrusion, the cover provides for visual inspection for termites, and the opening allows for drainage of moisture. A significant drawback to this system is that termites can still gain access to a building by intruding through the opening and burrowing up through an outer layer of the wall to find an access route into the building.
Other known systems are directed to killing termites and other pests without addressing the underlying problem of moisture damage. Spraying pesticide on the ground adjacent the bottom of an exterior wall provides some protection, but is proscribed in many low-lying coastal areas, including but not limited to parts of Florida and Louisiana, because of seepage into the water table.
One known system provides a pesticide distribution system for a building with perforated tubing installed in the interior space of the building walls, with all the tubing branching from one trunk line. The trunk line extends through an exterior wall and provides for receiving a pesticide from outside the building. The pesticide drains through the perforations in the tubing and down to the floor within the interior space of the wall to create a barrier to termite intrusion. A significant drawback to this system is that termites can travel up the outer wall, over the tubing and into the building. Also, because the tubing is installed in the interior space of walls, termites can still infest and destroy outer layers of the wall such as substrata board, plywood, insulation board, and external gysum. The system is only applicable for new construction, with the tubing installed within the walls as the building is erected. Many industry groups, including various code writing authorities and stucco manufacturers, have been struggling unsuccessfully for
A Phi Dieu Tran
Bernstein Jason A.
Bernstein & Associates, P.L.
Friedman Carl D.
LandOfFree
Article for flashing of exteriorwall surfaces does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Article for flashing of exteriorwall surfaces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Article for flashing of exteriorwall surfaces will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2607772