1. Field of the Invention
The present invention relates to a pitched roofing system, and particularly to a system for insulating the pitched roof and attaching roofing components, and a method for installing the system.
2. Description of the Related Art
There are two basic types of roofs: flat and pitched. Pitched roofs come in a few basic styles, all of which are relevant to the present invention. A duo-pitched roof has two sloping sides joined along the top with end vertical walls called a gable end. This is probably the most common form of pitched roof. If the end of the roof is also sloping it is termed hipped. If two sections of roof meet at an angle, such as a right angle, the junction between the two roof sections is termed a valley.
Various roof components are used as roof coverings on pitched roof decks. One example of a roof component is a roof tile. Roof tiles are extremely durable and provide significant aesthetic and decorative effects to the structures to which they are applied. Roof components or coverings as described herein may be made of cementitious materials and also brick, stone, clay, plastic, wood, metal, rubber or bituminous materials.
A typical pitched roofing system includes sheets of wood, typically plywood or decking material, nailed to the truss rafters to form a pitched roof deck. Other pitched roof decks may be made with materials such as steel or concrete. Typically, the pitched roof deck is overlaid with a roof substrate made of a waterproofing material. Typically, the waterproofing material forming the roof substrate is a roll goods membrane or underlayment comprising one or more plies of asphaltic or modified bitumen impregnated felt attached to the pitched roof deck. The felt is typically attached to the pitched roof deck by nails and/or adhesive. Felt is generally made of wood pulp and rag or of asbestos, polyester or glass fibers. Self-adhering membranes, commonly referred to as “peel and stick,” may also be used. These membranes are generally modified bitumen impregnated fiberglass or polyester fibers. Some pitched roof systems having steel or concrete decks do not require the use of a waterproof membrane or coating.
Roof components are primarily secured to the pitched roof deck with mechanical fasteners. Nails are the primary mechanical fasteners for securing roof components to a wood deck. Typically, tile roof components are secured with nails, inserted through holes in the tile roof component, driven into and through the roof substrate and wood deck. Mortar is sometimes used in conjunction with nails to provide holding force of the tile roof component to the roof deck. In either case, it is undesirable to drive numerous holes through the roof substrate and wood deck since these nail holes provide a potential leak path in the pitched roofing system. High wind loading conditions also affect the roof components secured with nails. In areas near salt water the effectiveness of nails is diminished over time due to corrosion of the nails. Additionally, nails get loose over a period of time. Some decks, such as concrete or steel decks, cannot be nailed into. Non-nailable decks (concrete, steel, etc.) use a wire tie or other cumbersome and expensive system to fasten the roof components to the pitched roof deck.
As stated above, mortar or similar binders are often used as a secondary fastener between tile roof components and the roof substrate. Using mortar is a slow procedure and labor intensive as the mortar must first be prepared, typically at ground level, in buckets which must then be raised to the pitched roof deck, and then the mortar is applied to the roof substrate. The mortar adds unnecessary weight to the roofing system. The set-up time of the mortar increases the time required to form the bond between the tile roof component and the roof substrate. The installed tile roof components should not be disturbed until the mortar has set-up as movement of the tile roof component affects the bond. Furthermore, the strength of the completed bond between the tile roof component and the roof substrate can be unsatisfactory. Typically, an approximate 60-pound tensile load applied transversely to the tile roof component will break the mortar bond between the tile roof component and the roof substrate. During high wind loading conditions, such as that experienced during a hurricane or a tornado, the tile roof components frequently release from the roof structure and become life threatening, flying projectiles. During such events, the tile roof components are widely strewn about and scattered throughout the area. The flying tile roof components result in additional danger during these devastating events and further increase the tremendous burden of clean up after these catastrophic events.
Assignee's U.S. Pat. No. 5,362,342 discloses a method of bonding tile roof components to a roof substrate utilizing polyurethane foam as the bonding medium. The method includes the step of applying under low pressure a stream of two component foamable liquid polyurethane on a prepared roof substrate. The foamable liquid polyurethane has a density preferably in the range of one and one-half to two pounds per cubic foot and a reactivity period in the range of one and one-half to four minutes. The foamable liquid polyurethane is preferably applied at a rate in the range of two to three pounds per minute. The tile roof component is placed into contact with the foamable liquid polyurethane during the reactivity period of the foamable liquid polyurethane. The bond between the tile roof components and the roof substrate with the polyurethane foam is several times increased over the mortar and mechanical bonds.
Another type of roof component used is a roof panel, typically made of metal. Roof panels are often used to form a standing seam roof. A typical standing seam roof utilizes adjacent interlocking elongated panels which are affixed at their edges. Typically, the standing seam roof panels are generally flat with upstanding interlocking ribs extending the length of the elongated panel. Separate attachment clips or fasteners spaced along the standing seam are typically utilized to attach the panel to the roof deck or substrate. The fasteners, in some instances, include nails or screws penetrating the roof panel. Problems exist in trying to secure such panels to a roof so that they survive substantial wind conditions and the capillary action of water (and the problems it causes to the underlying roof structure). Roof panels are available in a variety of sizes, shapes and materials. For example, some roof panels are approximately 12″ wide and have a length of 40′ while some roof panels have a width of approximately 36″ and lengths ranging from 2′ to 20′. Some roof panels are “stepped” to create a tile-like appearance and are commonly referred to as “tile panels.” A typical tile panel, typically made of metal, gives the appearance of rows of overlapping Spanish tiles without the weight of Spanish tile. A single 36″ wide by 20′ panel covers as much area as 80 tiles at just a fraction of the weight.
It is desirable to provide an energy efficient pitched roofing system at a reasonable cost. Thus, it is desirable to have a pitched roofing system that provides insulation to reduce energy consumption. It is also desirable that the method of installation be a simple operation, non-labor intensive, economical and not require excessive installation time. It may also be desirable to minimize the difficulty of precisely aligning and installing the rows of roof components to assure the most aesthetically pleasing appearance of the installed roofing system. Additionally, the pitched roofing system should withstand the long-term effects of temperature and climatic variations experienced by the pitched roofing system under normal circumstances.
One embodiment of the present invention includes an insulated pitched roofing system and method of installation for a sloped or pitched roof deck of wood, metal, concrete or other material. The pitched roofing system according to an embodiment of the present invention is energy efficient and is particularly suited to a roof having a 2:12 pitch or greater.
An insulating component according to an embodiment of the present invention includes a board or sheet material which is adhered to the roof deck. Preferably, the sheet material includes a substantially flat lower surface and an upper surface. The lower surface is preferably adhered to the roof substrate on the roof deck with a polymer adhesive. Preferably, the roof components, such as roof tiles or roof panels, are adhered to the upper surface of the sheet material with the polymer adhesive.
An alternative embodiment of the present invention includes the sheet material having a contoured upper surface corresponding with the tile profile to be installed. The contoured upper surface provides guidance in properly placing and aligning the roof tiles on the roof for ease of installation and a more pleasing appearance.
The method of installing the pitched roofing system according to an embodiment of the present invention is a simple operation, non-labor intensive, economical and does not require excessive installation time. The pitched roofing system will withstand the long-term effects of temperature variations and climatic conditions experienced by the pitched roofing system under normal circumstances.
The objects, advantages, and features of the invention will become more apparent by reference to the drawings which are appended hereto and wherein like numerals indicate like parts and wherein an illustrated embodiment of the invention is shown, in which:
The insulated pitched roofing system and method of installing same, generally designated as 100, will now be described in greater detail with specific reference to the drawings. Referring to
As shown in
A pitched roof deck, generally designated as 50, is shown in
Preferably, a roofing substrate 20 forming a waterproof coating is applied and preferably bonded to the upper surface of the decking material 52. The roofing substrate 20 can be a felt, commonly used in the roofing industry. The felt is a roll goods membrane that is fastened to the decking material 52, typically with mechanical fasteners such as nails and/or bonded to the decking material with, for example, tar or bitumen. The felt is typically applied along the length of the roof with an adjacent row of the felt overlapping the edge of the prior row of felt. The roofing substrate 20 protects against rain and moisture coming into contact with and passing through the pitched roof deck 50. It is to be understood that in some circumstances the roofing substrate 20 may not be desired or necessary for the present invention.
Referring to
The roof components 10 are preferably adhered to the upper surface 22a of the sheet material 22 with an adhesive, such as the polymer adhesive 40. Preferably, the polymer adhesive 40 is a polyurethane described in greater detail below. A method of attaching the roof components 10 to a roofing substrate and a typical polymer adhesive 40 are disclosed in assignee's U.S. Pat. No. 5,362,342, issued to Murray et al., which is incorporated by reference. However, it is to be understood that the present invention is not limited to the method and adhesive disclosed in U.S. Pat. No. 5,362,342.
One method of attaching the roof components 10 with the polymer adhesive 40 is shown in
According to one embodiment of the present invention, the polymer adhesive 40 may be a foamable or a non-foamable polymer adhesive. Preferably, the polymer adhesive 40 is a polyurethane adhesive, and more preferably a plural component polyurethane adhesive. The significant advantage of the plural component polyurethane adhesive is being able to walk on the installed roof components 10 shortly after the roof components 10 have been installed without affecting the bond between the roof component 10 and insulating sheet 22. The reactivity period or rise time of the plural component liquid polyurethane adhesive 40 of the present invention is preferably about one-half to about ten minutes and most preferably about one and one-half to about four minutes. It is important that the roof component 10 be properly placed during the reactivity period to achieve the required bonding of the roof component 10 to the insulating sheet 22. During the reactivity period, a foamable polyurethane adhesive 40 is an expanding foam, which will fill gaps and imperfections. The resulting foam provides excellent bonding between the roof component 10 and the insulating sheet 22 due to the adhesive properties of the urethane. It has been found that a reactivity period of less than about one-half minute makes it difficult to timely place the roof component 10 during the reactivity period.
The foamable liquid polyurethane 40 is preferably a froth foam. Froth foam chemistry is well known in the art of urethane foams. The froth foam may be formed by using blowing agents such as hydrogenated chlorofluorocarbon R22 (HCFC-R22), hydrogenated fluorocarbon 134A (HFC-134A), or chlorofluorocarbon R12 (CFC-R12). Preferably, the froth foam 40 is formed by using the hydrogenated blowing agents HCFC-R22 or HFC-134A, and not CFC-R12 due to CFC-R12's reported deleterious effects to the earth's ozone layer.
Preferably, the froth foam 40 has a consistency similar to a foamy shaving cream. The froth foam is preferable over other types of foams because it can be neatly and accurately dispensed without blowing or overspraying onto other areas of the roof deck or onto the outer surface of adjacently installed roof components 10. The preferred liquid polyurethane 40 with its shaving cream consistency does not run when placed onto a steeply pitched roof, but remains where it is installed on the insulating sheet 22. This ensures that the adhesive bond will be formed at the appropriate locations of the roof component 10. Additionally, the froth foam 40 begins expanding immediately upon application to the insulating sheet 22 and results in a firm bond with the underside of the roof component 10.
The liquid polyurethane 40 preferably has a density of about one to about eight pounds per cubic foot. It may be desirable to minimize the density of the liquid polyurethane 40 to minimize the weight on the roof while still providing an excellent bonding of the roof component 10 to the insulating sheet 22. It has been found to be most preferable to have a foam density of about one and one-half to about two pounds per cubic foot. The application rate of the liquid polyurethane 40 is preferably about one to about six pounds per minute and most preferably about two to about three pounds per minute.
Referring to
Referring to
As shown in
It is to be understood that the present invention is an insulated pitched roofing system and method 100 that can be used on pitched roof decks 50 made of various materials, including but not limited to wood, metal and concrete. The system 100 according to an embodiment of the present invention includes an insulating sheet 22, 220 adhered with a polymer adhesive 40 to the pitched roof deck 50 or the roof substrate 20 attached to the pitched roof deck 50. The roof components 10 are adhered with the polymer adhesive 40 to the insulating sheet 22, 220. The upper surface 220a of the insulating sheet 220 may be contoured to aid in properly placing the roof components 10. The improved roofing system 100 provides a well insulated roof for energy efficiency.
A few embodiments of a pitched roofing system and method of installing same according to the present invention have thus been set forth. However, the invention should not be unduly limited to the foregoing, which has been set forth for illustrative purposes only. Various modifications and alterations of the invention will be apparent to those skilled in the art, without departing from the true scope of the invention.
This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/294,959, filed Nov. 14, 2002, which claims priority from Provisional Application Ser. No. 60/334,787, filed on Nov. 15, 2001. Applicant incorporates by reference herein U.S. patent application Ser. No. 10/294,959.
Number | Date | Country | |
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60334787 | Nov 2001 | US |
Number | Date | Country | |
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Parent | 10294959 | Nov 2002 | US |
Child | 11881073 | Jul 2007 | US |