TγγLE OF THE INVENTION

Method and Device for Resilient Seal System

BACKGROUND OF THE INVENTION

Field of the Invention. The present invention relates generally to systems and

5 methods for creating a seal system between adjacent panels subject to temperature expansion and contraction. More particularly, the present invention is directed to providing seals in construction joints that are resilient, and ideally waterproof, over relatively long periods of time.

Description of the Related Art. Construction panels come in many different sizes

1.0 and shapes and may be used for various purposes, including roadways, sideways, and precast structures. In many situations it is necessary to form a lateral gap or joint in the structure to allow for independent movement of the adjacent sections. Such movement is caused by many factors including expansion and contraction of the adjacent sections due to changes in temperature.

15 Various seal systems and configurations have been used to seal such gaps or joints.

One popular technique involves pressing a flexible rod or tube into the gap or joint The rods or tubes are typically made from some type of foam material and are commonly referred to as "backer rods". The remainder of the gap or joint above the tube is then filled in with a sealant. The backer rod does not add any waterproofing value, as it is only used to

20 control the depth of the sealant. Another method is to use pre-compressed saturated, foam tapes. Pre-compressed foam tapes can require additional time to be sized to the particular distance between any two panels, which may vary slightly or significantly. Such variations also require a variety of sizings to be readily accessible for the particulars of any single gap. Such pre-compressed tapes are expensive. Another method is to combine the sealant

25 and the pre-comprcsscd foam tape; however such a method may require additional time because each joint must be coated with the sealant along its entire length, which may be five to seven feet, allowed to cure, then be compressed into the "precompressed" state for installation.

The seal system is intended to deter water and other contaminants from entering the

30 gap or joint. It is important that the seal be effective over relatively long periods of time and that it function properly even when exposed to extreme weather conditions. Major problems with seals include water penetration and contaminant penetration. Water penetration may result in exposure of -unsealed surfaces or in freezing expansion. In the

case of a seal where at least one panel contains wood, water penetration of the seal may result in rotting, particularly as the water may become trapped within the seal or gap. In the case of a seal where at least one panel contains masonry, the water may penetrate into the masonry and expand when cooled below its freezing point, creating internal stresses on the masonry and potentially fracturing the masonry. In all instances, penetration of water may result in further destruction of the seal should the water cool below its freezing point. Contaminant penetration may also have detrimental effects on the gap or seal. As the gap or seal is intended to permit expansion of the panels into the gap or seal, the presence of non-flexible contaminants may prevent such expansion and contribute to the increase of stresses and strains within the panels.

It is known that such flexing and conditions may have a detrimental effect on the seal between the panels. Flexing may fatigue the sealant, which has limited flexibility and elasticity. Weather conditions may alter the flexibility and elasticity of the sealant so as to result in cracking. It is known to introduce the sealant into the space between the adjacent construction panels in two applications, forming two seals, so that if one seal fails, the other may remain waterproof. However the conditions which cause failure of the first seal layer may also cause the second substantially identical seal layer to fail.

Another difficulty in applying such sealants is to ensure that the sealant completely fills the gap or joint as it then exists and adequately attaches to the adjacent panels. This may be accomplished by increasing the nozzle size, by slowing the rate at which the applicator is moved while increasing the rate of application, or by hand tooling. Increasing the nozzle size creates problems as the optimum nozzle size is the approximate width of the distance between adjacent panels at the lowermost portion of the gap or joint, which becomes difficult to reach with a full width nozzle. Slowing the rate of application, while effective, slows the construction process, increases manpower requirements, and may require additional time for staging and scaffolding use, all of which are undesirable.

A further difficulty in apply such seals is that time necessary to apply multiple seal layers. The second seal cannot be applied before the first seal has sufficiently cured as to prevent the seals from becoming intertwined or not allowing air required to cure and therefore transferring destructive forces between themselves. Moreover conventional seals require each seal to be applied and worked by hand to ensure adherence to the adjacent panels and sufficient penetration into the gap or joint. Such conventional seals may require skilled labor, further consuming additional time.

It would be an improvement to the art to have a seal system, and a method for application of such seal system, which would provide a seal having a longer duration of use, which would better seal adjacent panels regardless of distance and which could be rapidly applied without the need multiple sized backer rods. It would be a further improvement to increase the speed of application, and to reduce costs, labor requirements, and material needs. It would be a further improvement to have a second seal which would not fail due to the same conditions as a first seal.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, a seal system and method are provided for slowing deterioration at joints or gaps and for providing a second seal having physical properties different from the first seal.

The method for creating a resilient interface to deter water and contaminants from entering the joint or gap adjacent construction panels in accordance with the present invention includes introducing a foaming liquid expansive elastic closed-cell liquid- impermeable sealant between the two adjacent panels with sufficient volume to fill the distance between the two panels and adhere to each. A seal is then introduced above the foamed liquid expansive elastic closed-cell liquid-impermeable sealant with sufficient volume to also fill the distance between the two panels and adhere to each. The seal may be by application of one or more gunnablc sealants, which are well known in the art, typically being sold tn a tube form tor use with a caulking gun. Alternatively, the seal may comprise an extruded resilient member affixed in gap with adhesive sealant on each side.

The extruded resilient member may be one or more from the group of neoprene, santoprene, silicone, and urethane. A backer rod may be inserted in the seal between the layering of sealant and the seal to control sealant application depth and to contour the first sealant.

The resulting structure of the seal system provides a resilient interface intermediate a first construction panel and a second construction panel including a first seal composed of a foaming, expansive elastic closed-cell liquid-impermeable sealant, potentially a backer rod, and finally a second seal. The above described and many other features and attendant advantages of the present invention will become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.

Accordingly, the objects of my invention are to provide, inter alia, a seal system

that:

• extends the lifespan of the seal;

• extends the lifespan of the adjacent panels;

• utilizes at least two different seals to increase longevity; • can include a backer rod to absorb some of the load and to provide further impediments to external articles invading the lower seal.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross sectional view of the seal without the backer rod. Figure 2 is a cross-sectional view of the seal with the backer rod. DESCRIPTION OF THE INVENTION

As shown in Figure 1, the seal system 10 comprises of a foaming sealant 20 and a seal 40 applied between adjacent first panel 110 and second panel 120.

Foaming sealant 20 is a sprayed-in-place, elastic closed cell hydrophilic/phobic sealant that expands when exposed to air, is impermeable to water and cures rapidly. Because the foaming sealant 20 expands and fills the joint when dispensed, seal 40 may be applied almost immediately thereafter. In one embodiment foaming sealant 20 may be a polyurcthane-based sealant. No hand working of foaming sealant 20 by the applicator is necessary once applied. Foaming sealant 20 expands upon contact with air/moisture and is applied in sufficient volume to expand to completely cover the distance between first panel 110 and second panel 120 and to adhere to first panel surface 111 and to second panel surface 121, forming a first resilient seal. Foaming sealant 20 is elastic, therefore not detaching from first panel surface 111 or from second panel surface 121 during expansive cycling. Moreover the elastic property of foaming sealant 20 permits foaming sealant 20 not to internally shear or fail between first panel surface 111 and to second panel surface 121 during expansive cycling.

Seal 40 is seal of any material known in the art. In the preferred embodiment, seal 40 is a standard gunnable sealant, including acrylic-latex-based caulk, polysulfide-based caulk, urethane-based caulk, poly-urea-based caulk, and silicone-based caulk. As is known in the art seal 40 is not foaming or expansive, but is instead applied with a compressing "gun," such as a caulking gun, as a highly viscous liquid, which may be worked in place, including by increasing the nozzle size, by slowing the rate at which the applicator is moved while increasing the rate of application, or by hand tooling. Such adjustments may be necessary to ensure seal 40 adheres to both first panel surface 111 and second panel

surface 121. In an alternative embodiment (not shown), seal 40 may comprise an extruded resilient member affixed about gap 50 with adhesive sealant. The extruded resilient member may be one or more from the group of neoprene, santoprene, silicone, and urethane. Iti operation, foaming sealant 20 is applied to gap 50 in sufficient volume to expand to adhere to both first panel surface 111 and second panel surface 121. After time for outer surface 21 of foaming sealant to cure sufficiently to become semi-rigid, seal 40 is applied into gap 50 above foaming sealant 20 in sufficient volume to contact or be worked into contact with panel surface 111 and second panel surface 121. Tn the alternative embodiment depicted in Figure 2, a backer rod 30 may be located between foaming sealant 20 and seal 40. Backer rod 30 is constructed of a foam or other material, which is cut to length on site and which is intended as a spacing member. Backer rod 30 provides additional support for the forces exerted on foaming sealant 20 and on seal 40 from contact with panel surface 111 and/or second panel surface 121. Moreover backer rod 30 serves to prevent contaminants that may pass seal 40 from reaching foaming sealant 20. Finally, backer rod 30 may be inserted immediately after application of foaming sealant 20, including at times prior to the sufficient curing of foaming sealant 20 for outer surface 21 to become semi-rigid. Seal 40 may therefore be applied nearly immediately after application of foaming sealant 20. In operation for the alternative embodiment depicted in Figure 2, foaming sealant

20 is applied to gap 50 in sufficient volume to expand to adhere to both first panel surface 111 and second panel surface 121. Backer road 30 is inserted into gap 50 atop foaming sealant 20. Seal 40 is then applied into gap 50 above backer rod 30 in sufficient volume to contact or be worked into contact with panel surface 111 and second panel surface 121. The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.