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US 4,045,934 AGranted
Roof and method of preparation
AssigneeThe Dow Chemical Company
InventorsJames P. Sheahan, Lowell E. Putnam
Life of this patent
Estimating the term…
Abstract
Ponding is eliminated or substantially reduced on flat roofs by employing a closed cell, thermally insulating foam above the water barrier layer and varying the thickness of the closed cell foam to displace at least a majority of water which might accumulate in areas subject to ponding.
Claims9
A roof structure, the roof structure comprising in cooperative combination
- a roof support means, the roof support means carrying thereon
- a roof deck, the roof deck supporting
- a water impermeable membrane, the water impermeable membrane having a generally flat surface generally coextensive with the roof and deck,
- a first layer of closed cell plastic foam insulation adjacent the membrane and remote from the deck, the membrane and first layer defining at least one generally upwardly facing
- cavity in which water does not drain under the influence of the force of gravity,
- the improvement which comprises
- at least one second layer of a closed cell plastic foam disposed within the cavity, the plastic foam of the second layer being present in a quantity sufficient to displace at least a major portion of water which would collect in the cavity under the influence of the force of gravity.
4 more elements
A method for roofing and reroofing, the steps of the method comprising;
- providing an upwardly facing roof surface having a first layer of closed cell plastic foam insulation thereon, the roof surface being subject to ponding, that is the collection of water in at least one upwardly facing cavity of the roof surface under the influence of gravity, the cavity being so arranged that water collected therein is not displaced therefrom by the force of gravity,
- the improvement which comprises
- disposing within the cavity a second layer of closed cell plastic foam sufficient to displace at least a major portion of water which would otherwise collect in said cavity.
Dependencies are inferred from the claim text.