Patent Application
20100055430
Buildings have peripheral side walls supporting roof structures that define interior enclosures. Lower areas, such as crawl spaces, frequently might have only dirt and/or dirt/stone floors. Gases including water vapor and the potentially toxic radioactive Radon gas might then be discharged via the unsealed crawl space floors into the building enclosure. This can be unhealthy and/or uncomfortable to the building occupants.
Recognizing this, it is common to spread a thin vapor barrier, such as a plastic sheet, over the dirt crawl spaces floor so as to restrict free passage of these gases. However, many existing plastic barrier sheets are either so thin to easily puncture or rip or so thick to be heavy and difficult to be properly positioned.
This invention relates to an improved composite planar sheet vapor barrier suited for preventing the passage of gases there through.
The improved composite planar sheet barrier is sufficiently light weight to be spread out flat at many building locations, but yet tough, durable and highly resistant to the transverse passage of water vapor or other gases, for improved thermal, moisture and draft control and personal comfort.
The improved composite planar sheet barrier can be formed of three generally planar sheet-like components overlaid and secured together. It is durable and resistant against punctures and tears, can be offered in convenient sizes (possibly 6 to 12 feet wide) and stored on rolls to allow easy layout over a floor or the like, and can be sufficiently light for easy installation in being laid out flat with adjacent edges overlapped and tapped together, suited even for broad area coverage if needed.
The inventive planar barrier might be formed of three different generally planar sheet components overlaid and secured together. Lamination under heat and pressure is a preferred manner of securing the components together in forming the composite vapor barrier sheet. Adhesive could also or alternatively be interposed between the adjacent planar components.
One main use of this barrier might be to spread it out over a crawl space dirt floor, possibly even having its edges rise up and overlie the lower inch or so of the foundation wall. The edges of the different composite sheets could be overlapped and taped together, and tape could also secure the sheet edges to the adjacent foundation wall.
These and other objects, features or advantages of the invention will be more fully understood and appreciated after considering the following description of the invention, which includes the accompanying drawings, wherein:
A vapor barrier sheet 10 is formed of several different generally planar sheet-like components 12, 14, and 16 that are overlaid or sandwiched and secured together to form the composite sheet 10.
One outer planar sheet component 12 is comprised of aluminum foil 20, with one face being coated with a thin film 24 of polyethylene or similar PVC. The cured film coating 24 on the foil significantly reinforces the foil against tearing or ripping, and without materially reducing the foil flexibility.
The other outer planar component 16 can be a thin sheet 28 of plastic, possibly reinforced by intersecting integral plastic formations or filaments 30, that can be arranged in a precise manner such as by meeting or crossing at specific angles, and/or with more random contact orientations.
The middle planar component 14 can be a foamed plastic sheet, only being much thicker than either of the other planar components 12, 16.
The two outer planar sheet components 12, 16 are bonded to the opposite faces of the foamed middle sheet component 14 in forming the vapor barrier sheet 10. One manner of bonding such components might be by laminating them together between compression rollers (not shown), using both local pressures (possibly 100-1000 psi) and elevated temperatures (possibly between 250-1000 degrees F. Adhesive could also be used to hold the sheets overlaid and secured together.
Thus, the planar sheet sections 12, 14 and 16 are sandwiched fixedly together, with one outer sheet section being of aluminum foil having a thin film of polyethylene on it outer face, with the other outer sheet section being of plastic having reinforcing filaments thereon, and with the thicker middle sheet section being of a foamed plastic.
More specifically, each of the outer planar sheet sections might be between 0.005″-0.05″ thick, while the middle planar sheet section might be between 0.01″-0.10″ thick. Also, the film of polyethylene on the outer face of the one outer sheet section might be between 0.0005″-0.005″ thick.
Of significance, the separated thin outer layers sandwiching the thicker middle layer appreciably strengthens the composite vapor barrier sheet 10, although the sheet is still lightweight and flexible, and can be easily shaped around or over corners. The cured coating 24 of the foil preferably could be located on one outside face of the composite sheet. The sheet vapor barrier might have an overall thickness possibly between 0.01″-0.10″.
The different composite sheet layers can be sandwiched together in the manner noted, in varying widths and lengths, including widths of possibly 6 to 12 feet and lengths of 50, 100 or even more feet, which could then stored on rolls (not shown).
Nonetheless, the composite barrier sheet 10 could be laid flat over the crawl space floor 30 to be covered as needed. When covering a floor area larger than a single composite barrier sheet, second barrier sheets 10′ could have its edge overlap by an inch or so the edge of a barrier sheet 10 already on the floor, and tape 34 can overlie and secure the overlapped edges together. When covering a crawl space floor, the sheet edge could be folded approximately 90 degrees up from the floor to lie with an inch or so flush against the foundation wall 32, suited then to be taped to the wall.
Support posts 36 might also rise up from the crawl space floor, and the separate composite sheets might have edge cutouts for receiving the posts, and tape 34 can be used for closing any gaps between the sheet and post.
