High Traction Roofing Underlayment

This application is a continuation of International patent application No. PCT/EP2024/052667 having an international filing date of Feb. 2, 2024, which claims the benefit of priority to U.S. provisional application No. 63/443,241, filed on Feb. 3, 2023 and U.S. provisional application No. 63/579,171, filed Aug. 23, 2023; this application also claims the benefit of priority to U.S. provisional application No. 63/685,392, filed on Aug. 21, 2024; the entireties of all prior applications are hereby incorporated by reference herein.

The invention relates to high traction roofing underlayment having a fabric on an exposed side to provide better traction for workers on a roof.

Roofing underlayment is used to provide a layer of additional resistance for moisture to pass through the roof into the building and may be non-breathable synthetic material. The roofing underlayment is applied over the plywood and shingles are mechanically attached to the roof, such as by roofing nails through the shingle, through the roofing underlayment and into the plywood. Roof underlayment may be configured with a surface adhesive strip that is configured to bond with the adhesive layer of another piece of roof underlayment when overlapped on a roof. Roofing underlayment can be low friction or slippery, especially when wet and this can lead to falls and injury. Many roofs are configured at an angle and therefore there is a high propensity for falls.

Some roof underlayment has sand attached to the surface side of the underlayment to provide additional friction and traction for those walking on the underlayment. The sand does not effectively stick to the underlayment and provides only marginal improvements in traction. The underlayment with a sand or particle coating is therefore slippery and dangerous, especially in wet conditions.

The invention is directed to a high traction roof underlayment comprising a barrier layer with an adhesive configured on a roof side and a high friction layer configured on a surface or exposed side when configured on a roof. The high friction layer may be a fabric having fibers and may be woven or a non-woven fabric. A high friction layer may preferably be a non-woven as these materials are less expensive than woven material and can provide a high friction for traction on the surface side of an underlayment. An exemplary fabric may be a fleece fabric that is woven and the brushed to produce a napped surface. Fleece is typically made with synthetic polymer fibers, such as polyester, but can be made with natural fibers, such as wool.

The traction layer may include a fabric having fibers and may be woven or a non-woven fabric and includes a high friction layer that may be a continuous or discontinuous layer. A fabric layer of the traction layer may preferably be a non-woven as these materials are less expensive than woven material and can provide some traction and may be well suited for bonding to the high friction layer on the surface side of an underlayment. A fabric layer of the traction layer may be embossed to produce a non-uniform thickness and the friction layer may be attached to the peaks or raised portions of the embossed fabric layer.

An exemplary high friction layer may include a discontinuous high friction layer that has gaps between portions of the high friction layer. The high friction layer may include bands or bands of high friction material separated by gaps between the bands. The bands may extend along the length of the high traction roof underlayment, wherein the bands run across the roof to provide effective contact with a shoe that may begin to slip down along the high traction roof underlayment. The high traction roof underlayment is typically provided in a roll of high traction roof underlayment having a length wrapped into a roll and a width. The roll of high traction roof underlayment is rolled across a roof with a first edge along a top or elevated on a pitched roof over a second edge. The bands of high friction material may extend along the length of the roll such that if traction is lost, the foot would have to traverse over bands of high friction material to better aid in regaining traction and footing to prevent falls. A roll of high traction roof underlayment may have a length of about 5 m or more, about 10 m or more, about 25 m or more and any range between and including the values provided.

The high friction layer may also include discrete high friction material that is surround by a gap in the high friction layer. Openings or gaps in the high friction layer may promote moisture to run off or out of the high friction material and thereby improve traction. Also, strips or bands or discrete high friction portions may dry out more quickly after becoming wet from precipitation. Furthermore, discontinuous and discrete high friction material has reduced weight over a continuous layer and this is desired.

A band of high friction material and the gaps therebetween may a width of about 10 mm or more, about 20 mm or more, about 30 mm or more, about 50 mm or more and any range between and including the width values provided. A discrete high friction material may occupy an area of about 100 mmor more, about 250 mmor more, about 1 cm, about 5 cmor more, about 10 cmor more and any range between and including the area values provided. Again, a smaller area may enable better drainage and may enable the high friction material to dry out quickly. However, a large enough area may be preferred to provide adequate traction, such as at last 250 mmor more. A high friction layer may have a height or thickness of about 1 mm or more, about 2 mm or more, about 4 mm or more, about 5 mm or more and any range between and including the thickness values provided. A large thickness may not be required to greatly increase traction and a lower thickness reduces weight, which is desirable, therefore thinner is preferred.

The friction layer of the high traction roof underlayment may be a continuous friction layer, discontinuous friction layer or a discrete friction layer. A continuous friction layer forms a film of high friction material on the high traction roof underlayment and may be bonded to the barrier layer or to a fabric layer. A discontinuous friction layer has opening or apertures in the friction layer and may include elongated friction portions that may crisscross each other to form a grid or may be some other pattern. A grid of bands of high friction material forms a discontinuous friction layer that may be contiguous, wherein the friction material is connected across the grid pattern A discrete friction layer has discrete friction portions that are not connected to other friction portions, wherein the discrete fiction portions have a closed perimeter. A discrete friction layer has friction material configured as discrete dots or other discrete geometric portions, including, but not limited to diamonds, polygonal shapes, and the like.

A preferred friction layer may be an interconnecting pattern of elongated high friction material, or bands of high friction layer material. A strand of high friction material is elongated having a length that is five times or more, and in most cases ten times or more the width of the strand. A strand of high friction material may extend continuously across the high traction roof underlayment. An interconnecting pattern may form discrete openings in the interconnecting pattern and may be a grid pattern. The grid pattern may include a first series of bands of high friction material and second series of stands of high friction material that is configured substantially orthogonally to the first series of bands of high friction material, or within about 20 degrees of orthogonal, to form a grid. The bands of high friction material may have a width of about 2 mm or more, about 4 mm or more, about 6 mm or more, about 8 mm or more and any range between and including the values provided. The distance between adjacent elongated high friction bands may at least the same as the width of one of the bands of high friction material forming the cell or opening in the grid and may be twice the width or more, or about five times the width or more, or ten times the width or more, or event 20 times the width or more. A grid pattern of bands of high friction material may be preferred as it may be more durable to abrasion and prevent peeling of the high friction material from the base material, the fabric layer or the barrier layer.

A high friction material is a material with a static coefficient of friction against stainless steel surface as defined by a Coefficient of Friction (COF) test under ASTM D1894 of about 0.35 or more, about 0.40 or more, about 0.5 or more, about 0.60 or more, and any range between and including the static coefficients of friction provided. A test block or sled for ASTM 1894 from The Universal Grip Company, Salem, MA is used in the testing and is the second surface against the material tested.

A high friction material may be a varnish, an elastomeric material such as a urethane or silicone.

A high friction material may have a thickness of about 5 μm or less, 10 μm or less, or about 0.01 mm or more, about 0.1 mm or more, about 0.25 mm or more, about 0.5 mm or more and any range between and including the values provided. The thinner the layer the less weight the high friction material adds to the high traction roof underlayment. A high friction material may be coated onto the barrier layer or onto a fabric layer and may be a wash-coat, a solution of friction material in a fluid carrier, the friction material may be dissolved in a liquid carrier or may be a suspension of solid particles in the liquid carrier.

A high friction layer may only cover a portion of the surface side of the high traction roof underlayment and may cover about 100% or less, about 95% or less of the area, about 80% or less, about 75% or less, about 50% or less, about 35% or less, about 25% or less of the area and any range between and including the values provided. A high area of coverage may provide improved slip resistance but may be more expensive and may make the underlayment much heavier which may make it more difficult to move onto a roof and manipulate on a roof. Also, a high coverage of the high friction layer would be more expensive. For these reasons a coverage of about 50% or less is preferred and 35% or less areal coverage is even more preferred. For higher coverage areas of the friction material, the thickness of the friction material may be very thin, such as less than 0.01 mm, or about 10 μm or less, for example and the friction material may be applied by a coating.

The adhesive on the roof side of the high traction roof underlayment may be a continuous adhesive layer, discontinuous or a discrete adhesive layer. A continuous adhesive layer forms a film of adhesive on the high traction roof underlayment and may be bonded to the barrier layer. A discontinuous adhesive layer has opening or apertures in the adhesive layer and may include elongated adhesive portions that may crisscross each other or some other pattern. A discrete adhesive layer has discrete adhesive portions that are not connected to other adhesive portions, or put another way, a discrete adhesive layer or portion has a closed perimeter.

A high traction roof underlayment may have a traction layer that is water resistant and/or water repellant to prevent liquid water from absorbing into the traction layer. A traction layer may be made of water repellant materials, or materials that do no absorb water, such as a polymer, or an elastomer, such as silicone. A traction layer may include a hydrophobic coating such as on or within a fabric layer of the traction layer, wherein the fabric is coated with a hydrophobic material to prevent water from absorbing into the fabric layer of the traction layer. Also, the friction layer may include a hydrophobic coating on the surface of the friction layer or material. The friction material may also be inherently hydrophobic such as a silicone high friction material.

The high traction roof underlayment may also be a self-adhering underlayment that includes an activator layer on the surface side that is configured to activate and bond with the adhesive when configured in contact on a roof. The activator layer may be a strip configured proximal an edge of the self-adhering underlayment, such that a second piece of self-adhering underlayment will overlay and contact this activator layer strip when installed on a roof. The activator layer may be configured to chemically react with the adhesive layer to enable adhesion between the layers. The activator layer may comprise a chemical that chemically bonds with the adhesive layer. The activator layer may not be a tacky adhesive and therefor a release liner for the activator layer may not be required. An activator layer may be non-tacky as defined as not adhering when pressed against the barrier layer of the self-adhering underlayment comprises for one minute with a pressure 70 kPa.

An exemplary high traction underlayment comprises a barrier layer, and an adhesive layer for bonding to a roof. The barrier layer may include a structural component such as a woven or non-woven fabric or scrim and a water barrier component, such as a polymer coating or film layer attached to the structural component. In an exemplary embodiment, the structural component is a woven material and the water barrier component is a coating of polymer on the woven structural component.

A water barrier component may be selected based on the application and location of use. Very wet areas may require a more substantial or thicker water barrier component while more arid locations may require minimal water barrier thickness. A water barrier component may include a polymer coating or a polymer film that may be olefin, polypropylene, polyethylene, polyester, polyurethane and the like. The polymer films maybe tensilized to increase the modulus. The polymer films may be uniaxially oriented, wherein they are tensilized in one direction, the machine direction, or they may be biaxially oriented, wherein they are tensilized in both the machine direction and cross-machine direction. The polymer films may have a thickness of about 10 mm or less, about 6 mm or less, about 4 mm or less, about 2 mm or less, or even about 1 mm or less.

A high traction underlayment may be a solid layer to prevent liquid water passage but may have a high moisture vapor transmission rate (MVTR) to enable moisture in the house to pass through the housewrap to prevent mold. An exemplary high traction underlayment may include a high MVTR layer including urethane, copolyester elastomer, microporous PP or PE, ethyl/ethylacrylate copolymer, ethyl/methylacrylate copolymer, and the like. This MVTR layer may be configured as the water barrier component. The moisture vapor transmission rate (MVTR) through the high traction underlayment according to ASTM E96-00 may be about 2.0 perm or more, about 3.0 perm or more, about 4.0 perm or more, and even at least 5.0 perm or more.

A high traction underlayment may be a solid layer to prevent liquid water passage but may have a high moisture vapor transmission rate (MVTR) to enable moisture in the house to pass through the housewrap to prevent mold. An exemplary self-adhering underlayment may include a high MVTR layer including urethane, copolyester elastomer, microporous PP or PE, ethyl/ethylacrylate copolymer, ethyl/methylacrylate copolymer, and the like. This MVTR layer may be configured as the water barrier component. The moisture vapor transmission rate (MVTR) through the self-adhering underlayment according to ASTM E96-00 may be about 2.0 perm or more, about 3.0 perm or more, about 4.0 perm or more, and even at least 5.0 perm or more.

An adhesive layer may be coupled to the barrier layer on the roof side to enable direct attachment to the exterior roof surface of a building. An adhesive layer may extend substantially over the entire roof surface of the high traction roof underlayment, or over at least 90% of the surface area. An adhesive layer may be a pressure sensitive adhesive that is configured in a continuous layer or as a discontinuous layer, such as dots or a grid or adhesive. The adhesive release liner is configured over the adhesive layer to prevent adhesion of adjacent layers when in a roll form.

Moisture vapor transmission rate through the barrier composite may be measured using ASTM E96-00 (Last Updated: Aug. 16, 2017), Water Vapor Transmission. ASTM E96 tests and evaluates the water vapor transfer through semi-permeable and permeable samples.

The summary of the invention is provided as a general introduction to some of the embodiments of the invention, and is not intended to be limiting. Additional example embodiments including variations and alternative configurations of the invention are provided herein.

Corresponding reference characters indicate corresponding parts throughout the several views of the figures. The figures represent an illustration of some of the embodiments of the present invention and are not to be construed as limiting the scope of the invention in any manner. Some of the figures may not show all of the features and components of the invention for ease of illustration, but it is to be understood that where possible, features and components from one figure may be included in the other figures. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Certain exemplary embodiments of the present invention are described herein and are illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention. Other embodiments of the invention, and certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, combinations, modifications, improvements are within the scope of the present invention.

shows a cross sectional view of layers of roof underlayment,′ of the prior art. Each layer of the roof underlayment has a barrier layer,′ and an adhesive release linerthat is configured between the adhesive layerof one layer and the barrier layer′ of the other layer of roof underlayment′. The barrier layer is on the surface sideand the adhesive layeris on the roof side.

shows a perspective view of the prior art roof underlayment with both release liners removed and the second roof underlayment′ attached to a roofby the adhesive layer′ on the roof sideof the roof underlayment. The barrier layerof each piece of underlayment is exposed to the surface for walking thereon and may be slippery.

Referring now to, an exemplary high traction roof underlayment systemincludes high traction roof underlayment,′ each having a barrier layer,′ an adhesive layer,′ on the roof sideand a fabric layer,′ on a surface side. The barrier layer may include a structural componentfor strength and a water barrier componentto prevent water passing through the high traction roof underlayment. An adhesive release liner,′ is configured over the adhesive layers,′ respectively when in a rolled configuration, as shown in. The fabric layermay have high friction and may be a woven or non-woven.

As shown in, the two pieces of exemplary high traction roof underlayment,′ are being attached together on a roofwith the fabric layeron the surface side. The first high traction roof underlaymenthas a widthfrom a first edgeto second edge′.

As shown in, the first piece of high traction underlaymentis being overlapped on the second piece of high traction roof underlayment′ such that the fabric layer′ of the second piece of high traction roof underlayment′ is contacting the adhesive layerof the first piece of high traction roof underlayment. The fabric layermay be configured to bond to the adhesive layer and provide a strong bond between the first piece of high traction roof underlayment and second piece of high traction roof underlayment.

shows a cross sectional view of layers of roof underlayment,′ of the prior art including a barrier layerand an adhesive release linerover the adhesive layerand a second surface adhesive linerover a surface adhesive stripconfigured on the surface sideto bond to the adhesive layerof a layered piece of roof underlayment when applied on a roof.

shows a perspective view of the prior art roof underlayment shown in, with both release liners removed and being attached to a roofwith the surface adhesive stripbonding to the adhesive layeron the roof sideof the roof underlayment.

Referring now to, a roll of high traction roof underlaymentincludes layers of high traction roof underlayment,′ that are rolled over each other. The high traction roof underlayment layers shown are self-adhering roof underlayment,′ having a barrier layer, an adhesive layeron the roof sideand a fabric layer,′ and activator layeron a surface side. The barrier layer may include a structural componentfor strength and a water barrier componentto prevent water passing through the self-adhering roof underlayment. An adhesive release lineris configured over the adhesive layer when in a rolled configuration, as shown in. The activator layer′ of the second high traction roof underlayment′ may have an activator chemical′ that is configured to chemically react with an adhesiveof the adhesive layerof the first high traction roof underlayment, and may cross-link with the adhesive of the adhesive layer.

As shown in, the two pieces of exemplary self-adhering roof underlayment,′ are being attached together on a roofwith the activator layer′ on the surface side′ of the second piece of self-adhering roof underlayment′ contacting the adhesive layeron the roof sideof the first piece of self-adhering roof underlayment. The activator layer will activate the adhesive to bond to the activator layer. The adhesive layer′ of the second piece of self-adhering roof underlayment′ is bonded to the roof. The first piece of self-adhering roof underlayment also has an activator strip that is configured to bond to the adhesive layer of a third piece of self-adhering roof underlayment when configured over the second piece of self-adhering roof underlayment.

As shown in, the activator layerhas a widththat may be a proportion of the overall widthfrom a first edgeto a second opposing edge′ of the high traction roof underlayment, such as about 20% or less, about 10% or less, or 5% or less. Put another way, the width of the activator layer may be about 10 mm or more, about 20 mm or more, about 30 mm or more, about 50 mm or more, about 100 mm or less and any range between and including the values provided.

As shown in, the first piece of high traction roof underlaymentis being overlapped on the second piece of high traction roof underlayment′ such that the activator layer′ of the second piece of high traction roof underlayment′ is contacting the adhesive layerof the first piece of self-adhering roof underlayment. Note that both the adhesive release liners are removed from the adhesive layer.

Referring now to, a high traction roof underlaymentmay have a discontinuous fabric layerthat may have gapsbetween portions of the fabric layer. As shown in, the discontinuous fabric layerincludes bands of fabricthat extend along the length of the high traction roof underlaymentwith gaps extending a gap widthbetween the bands of the fabric. The gaps and bands of fabric are elongated having a length that is at least five times greater than the width. The bands of fabrichave a widthand this width may be configured to provide adequate friction for a person walking on the high traction roof underlaymentwhen on a roof. Also, as shown in, the fabric layermay be configured an upper offset distancefrom the edge, a top edge when configured on a roof, wherein the surface adhesive stripand surface release linerare configured. Put another way, the fabric layermay be offset from the top edge to allow room for the surface adhesive stripand surface release liner. Likewise, the fabric layermay be configured a lower offset distancefrom the edge, a lower or bottom edge when the high traction roof underlaymentis configured on a roof.

As shown in, the high traction roof underlaymenthas a discontinuous fabric layerwith discrete fabric layersand gapsthat extend around the discrete fabric layers. This configuration may provide effective traction and may also prevent water from gathering on the surface as there is drainage between the discrete fabric layers or areas. The high friction fabrichas a lengthalong a length axis or direction of the high traction roof underlayment.

shows a cross sectional view of layers of roof underlayment,′ of the prior art. Each layer of the roof underlayment has a traction layer,′ on a surface side,′, a barrier layer,′, and an adhesive,′, on a roof sidethat bonds to the roof. The barrier layer is configured between the adhesive and the traction layer. The bottom edgeof the first roof underlaymentoverlaps the top edge′ of the second piece of roof underlayment′. The top edgeof the first piece of underlayment is configured above the bottom edge when the roof underlayment is configured on a pitched roof.

shows a perspective view of the prior art roof underlayment,′ being attached to a roofby the adhesive layeron the roof sideof the roof underlayment. The traction layerof each piece of underlayment is exposed to the surface on the surface sidefor walking thereon and can become slippery especially when wet.

Referring now to, an exemplary high traction roof underlaymenthas a traction layerthat includes a friction layeron a surface sideof the underlayment. The friction layermay be bonded to a fabric layer, which may be a non-woven fabric. Also, the fabric may be an embossed fabric layer, having raised areas that extend up from compressed areas. The friction layeris discontinuous on the surface and may include discrete friction portions having a bound or closed perimeter, such as dots or diamonds. The traction layermay be bonded to the barrier layerand an adhesive layer, containing an adhesive, may be bonded to the barrier layer on the roof sideof the high traction roof underlayment.

As shown in, the traction layermay include a hydrophobic coating, which may be configured on the friction layerand/or on a fabric layer. As shown in, a hydrophobic coatingis configured on the friction layer, such as on the discrete friction layerand a hydrophobic coating′ is configured on the fabric layer, such as a coating the fibers of a non-woven fabric.

As shown in, a traction layerincludes a discrete friction layerhaving discrete dots of friction materialhaving a closed perimeter, wherein each discrete dot of friction material does not contact the other discrete dots. As shown in, the friction layeris raised up from the fabric layerand the fabric layer is bonded to the barrier layer. The adhesive layeris bonded to the barrier layer on the roof sideof the high traction roof underlayment.

As shown in, a traction layerincludes a discrete friction layerhaving discrete dots of friction materialhaving a closed perimeter, wherein each discrete dot of friction material does not contact the other discrete dots. As shown in, the fabric layeris an embossed fabric layerhaving raised portionsand depressed portions. The friction layeris configured or bonded to the raised portionsof the embossed fabric layerand the fabric layer is bonded to the barrier layer. The adhesive layeris bonded to the barrier layer on the roof sideof the high traction roof underlayment.

As shown in, a traction layerincludes a discontinuous friction layerhaving elongated bandsof friction materialthat extend across the underlayment to form rows of friction material. The friction materialis bonded to the fabric layer. As shown in, the friction layeris raised up from the fabric layerto form groves in the friction layer which may effectively channel water to run off the underlayment. The rows may be configured to extend from a position proximal a top edgetoward a bottom edgeof the underlayment, or across the width of the high traction roof underlayment, or orthogonal to the length axisof the high traction roof underlayment. The fabric layer is bonded to the barrier layer. The adhesive layeris bonded to the barrier layer on the roof sideof the high traction roof underlayment.

As shown in, a traction layerincludes a discontinuous friction layerhaving elongated bands of friction materialthat crisscross each other on the underlayment to form a grid of frictionmaterial. Bands extend along the length axisand across the width from a top edgeto a bottom edgeof the high traction roof underlayment. The friction materialis bonded to the fabric layer. As shown in, the friction layeris raised up from the fabric layerto form a grid in the friction layer which may provide a very effective friction pattern and may be most durable, wherein abrasion of the grid is less likely to peel away a portion of the friction material. The fabric layeris bonded to the barrier layer. The adhesive layeris bonded to the barrier layer on the roof sideof the high traction roof underlayment.

As shown in, a first high traction roof underlayment, is bonded to the roofby the adhesive layerand a second high traction roof underlayment′ has a release linerconfigured over the adhesive layer′. The release lineris configured from removal from the adhesive layer′ to expose the adhesive′ on the roof side′ of the second high traction roof underlayment′. The second high traction roof underlayment′ can then be attached to the roof and to the first high traction roof underlayment. The bottom edgeof the first high traction roof underlayment′ overlaps the top edge′ of the second piece of high traction roof underlayment′. The top edgeof the first piece of roof underlayment is configured above the bottom edge when the roof underlayment is configured on a pitched roof.