Recreational vehicle roofing coating

1. A recreational vehicle roof comprising a layer of a rigid non-waterproof material, at least a portion of the layer having a coating formed from a solvent based polyurethane:

exhibiting an elongation at break of at least about 50%; wherein the polyurethane coating forms a waterproof membrane capable of stopping the transfer of water vapor, having a thickness of at least 10 mils.

2. The recreational vehicle roof as claimed in claim 1 wherein said solvent based polyurethane coating comprises the reaction product of a composition comprising a first part and a second part wherein:

said first part comprises about 50% to about 90% by weight of a urethane prepolymer formed from a polyol and an aliphatic isocyanate and about 10% to about 50% by weight of at least one organic solvent; and

said second part comprises about 5% to about 30% by weight of an aromatic or aliphatic amine, about 30% to about 60% by weight of a thixotrope, and about 0% to about 20% by weight of a pigment dispersion.

3. The recreational vehicle roof of claim 1 , wherein the rigid non-water proof material is formed from wood or a wood product.

4. The recreational vehicle roof of claim 3 , wherein the rigid non-water proof material is formed from at least one of wood, plywood, particle board, fiberboard, oriented strandboard, chipboard, and medium density fiberboard.

5. A recreational vehicle roof comprising a layer of a rigid non-waterproof material, at least a portion of the layer having a coating formed from a solvent free polyurethane:

exhibiting an elongation at break of at least about 50%; wherein the polyurethane coating forms a waterproof membrane capable of stopping the transfer of water vapor, having a thickness of at least 10 mils.

6. The recreational vehicle roof as claimed in claim 5 wherein said solvent free polyurethane coating comprises the reaction product of a composition comprising a first part and a second part wherein:

said first part comprises about 50% to about 90% by weight of a urethane pre-polymer formed from a polyol and an aliphatic isocyanate and about 0% to about 25% by weight of a diluent; and

said second part comprises about 5% to about 100% by weight of at least one aliphatic or aromatic amine.

7. The recreational vehicle roof of claim 5 , wherein the rigid non-water proof material is formed from wood or a wood product.

8. The recreational vehicle roof of claim 7 , wherein the rigid non-water proof material is formed from at least one of wood, plywood, particle board, fiberboard, oriented strandboard, chipboard, and medium density fiberboard.

9. A recreational vehicle roof comprising a layer of a rigid non-waterproof material, at least a portion of the layer having a coating formed from a water based polyurethane

exhibiting an elongation at break of at least about 50%; wherein the polyurethane coating forms a waterproof membrane capable of stopping the transfer of water vapor, having a thickness of at least 10 mils.

10. The recreational vehicle roof of claim 9 , wherein the rigid non-water proof material is formed from wood or a wood product.

11. The recreational vehicle roof of claim 10 , wherein the rigid non-water proof material is formed from at least one of wood, plywood, particle board, fiberboard, oriented strandboard, chipboard, and medium density fiberboard.

12. A recreational vehicle, comprising:

a vehicle body; and

a roof on at least a portion of said vehicle body, wherein the roof or portion thereof is made from a layer of non-waterproof material and at least a portion of the layer is coated with a substantially waterproof polyurethane coating, wherein:

the polyurethane coating comprises a single layer coating that forms a waterproofing membrane;

the polyurethane coating has a thickness of at least 10 mils;

the polyurethane coating has an elongation at break of at least about 50%; and

the polyurethane coating has a Shore A hardness of about 50 to about 90; and

wherein the portion of the recreational vehicle roof that is coated by the polyurethane coating is substantially waterproof.

13. A method of waterproofing a recreational vehicle roof comprising a layer of a rigid non-waterproof material, the method comprising:

applying a single coating of a polyurethane exhibiting an elongation at break of at least 50% to at least a portion of the layer of rigid non-waterproof material to form a waterproof membrane at least 10 mils thick on the layer of rigid non-waterproof material, wherein the waterproof membrane is capable of stopping the transfer of water vapor, and disposed such that the waterproof membrane is directly exposed to the atmosphere outside of the recreational vehicle roof;

subsequently forming at least one opening in the recreational vehicle roof, and

installing the recreational vehicle roof on a recreational vehicle.

14. A method of waterproofing a recreational vehicle roof comprising a layer of a rigid non-waterproof material, the method comprising:

forming at least one opening in the recreational vehicle roof;

subsequently applying a single coating of a polyurethane exhibiting an elongation at break of at least 50% to at least a portion of the layer of rigid non-waterproof material to form a waterproof membrane at least 10 mils thick on the layer of rigid non-waterproof material, wherein the waterproof membrane is capable of stopping the transfer of water vapor, and disposed such that the waterproof membrane is directly exposed to the atmosphere outside of the recreational vehicle roof; and

installing said recreational vehicle roof on a recreational vehicle.

15. A method of waterproofing a recreational vehicle roof containing a layer of a rigid non-waterproof material, the method comprising:

mixing a first part of a polyurethane composition with a second part of a polyurethane composition to form a mixture, wherein the polyurethane within the mixture exhibits an elongation at break of at least 50%;

applying the mixture using a method selected from spraying, troweling, rolling, and knifing, wherein the mixture is applied to at least a portion of the layer of rigid non-waterproof material to form a waterproof membrane at least 10 mils thick on the layer of rigid non-waterproof material, wherein the waterproof membrane is capable of stopping the transfer of water vapor; and

allowing the mixture to cure.