Patent Application
20060053699
1. Field of the Invention
The present invention relates to the field of flashing for the building industry. More particularly, the invention relates to corner flashing to seal corners at the base of foundation walls.
2. Description of the Prior Art
The use of flashing to protect buildings against water damage is well-known in the construction industry. Some areas of roofs and exterior walls are prone to leaks and water damage. These areas include an intersection between a chimney or window and a roof surface. Flashing, generally formed from a thin sheet of water-impermeable material, is used to protect a structure from damage by water. Edvardsen (U.S. patent appl. Pub. 2004/0103592 A1) discloses a two-part roof flashing kit for a roof-penetrating structure with two flashing portions that are adjustable to allow for use with roof penetrating structures of varying dimensions. Each of the two parts has a fold of material and the two parts are adjustably coupled with slidingly engaging the two folds. The disadvantage of the Edvardsen flashing is that the double fold requires additional material and fabrication time and provides greater bulk when the flashing is installed.
It is also well-known to use flashing to provide a moisture barrier at the base of foundations, particularly at the corners of foundations where water often collects, and beneath windows and doors. It is structurally and aesthetically important that the corner flashing fit properly for its intended use, that is, the lower horizontal portion lie flush on the foundation base, the vertical portion cover precisely the first two courses of blocks at the base of the foundation, and the upper horizontal portion then fit over the top edge of the upper block of the two courses, without buckling or leaving gaps. Because the dimensions of construction blocks typically used to construct foundation walls vary slightly from manufacturer to manufacturer, corner flashing is traditionally custom-fabricated off-site for a particular construction job, a costly and time consuming process. Pre-cast corner flashing is known, but it has a disadvantage in that it is not adjustable to the varying heights of construction blocks.
What is needed, therefore, is a corner flashing assembly that provides a water-impermeable seal around a corner at the base of a foundation wall and is easily adjustable to accommodate variations in the dimensions of construction blocks. What is further needed is such a corner flashing assembly that is easily and economically manufactured.
For the reasons stated above, it is the object of the present invention to provide a corner flashing assembly that provides a water-impermeable seal around the corner at the base of a foundation wall that is easily adjustable to accommodate variations in the dimensions of construction blocks. It is a further object to provide such a corner flashing assembly that is easily and economically manufactured.
The objects of the invention are achieved by providing a corner flashing assembly that fits neatly around the inside or outside corner of a building wall. The corner flashing assembly according to the invention comprises an upper corner piece and a lower corner piece. Each corner piece is shaped such that it neatly fits around the contour of the corner and has a vertical and a horizontal section. The horizontal section of the lower corner piece provides an apron on the foundation base at the base of the corner; with the vertical section extending upward over the wall face of perhaps two courses of construction blocks. The horizontal section of the upper corner piece is placed on the top face of the upper block of the two courses, with its vertical section extending downward over the face of the construction blocks. The vertical section of the upper corner piece overlaps a portion of the vertical section of the lower corner piece. This overlap is great enough to allow adjustability and also, barring catastrophic flooding, to prevent moisture seeping in between the upper and lower corner pieces.
The corner flashing assembly is made of copper. Copper is a desirable material for use in flashing because it is water-impermeable, it forms a protective patina in the presence of oxygen that is desirable and has aesthetic appeal, and, most importantly, does not corrode under the influence of the acids and alkalines that are present in conventional construction materials. Ideally, sections of the corner flashing assembly that will come into contact with mortar are coated with an asphalt coating, which improves the adhesion of the mortar to the copper.
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.
The upper corner 120 is also constructed as a single piece of copper that includes an upper horizontal section 121, an upper vertical section 124, and an upper vertical fold 128. Ideally, the upper horizontal section 121 is formed from a single sheet of material by making a 90-degree fold in the sheet to create the upper vertical fold 128. An upper section of the sheet is then folded perpendicular to the upper vertical section 124, to form the upper horizontal section 121. This fold creates an excess of material at a corner fold section 122. To facilitate this operation, a cut may be made in the upper section and some of the excess material removed. The material may be folded, trimmed, and/or soldered to form a gapless seam with the appropriate geometry to fit neatly around the outside corner CO.
To install the corner flashing assembly 100, the lower horizontal section 114 is placed on the foundation base B, with the lower vertical fold 118 flush around the outer corner CO. The upper horizontal section 121 is then placed along the top face of a construction block BT at the outer corner CO of the foundation wall W, with the upper vertical section 124 extending downward and and overlapping a portion of the lower vertical section 111, creating an overlap barrier 150. Once installed, a layer of mortar and another course of construction blocks is placed on top of the upper corner 120, securing and sealing it in place. Later, when flooring is installed, mortar will be applied to the apron formed by the lower horizontal section 110, thereby securing and sealing that portion of the flashing assembly 100.
The upper corner 220 is also constructed as a single piece of copper that includes an upper horizontal section 221, an upper vertical section 224, and an upper vertical fold 228. As in the first embodiment, the upper horizontal section 221 is ideally formed from a single sheet of material by making a 90-degree fold in the sheet of material. This forms the upper vertical fold 228 that fits into the inner corner CI. Then an upper portion of the material is folded perpendicular to the vertical plane, forming the upper vertical section 224. This creates a corner gap 235 bounded by a left edge 222 and a right edge 223. A gap panel 245 is soldered to the left edge 222 and the right edge 223 to form a continuous, gapless horizontal surface that, when the upper corner 220 is installed, fits neatly over the top face of a construction block BT and into the inner corner CI of the foundation wall W.
The preferred embodiments of the invention 100, 200 are constructed of copper. Ideally, a coating of asphalt is applied to all areas that will come into contact with mortar, as the asphalt improves the adhesion of mortar to copper.
It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the flashing assemblies may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.
