Plastic Crawl Space Access Device with Waterproof Tub
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Solution Overview
Problem
Current crawl space access systems are costly, time-consuming to construct, prone to water infiltration, and suffer from material degradation due to rust, requiring significant coordination and maintenance efforts.
Innovation Solution
A plastic, double-walled crawl space access device with a tub-like design, featuring a removable sump hole cover, that can be easily installed below grade level, secured to the wall with fasteners, and includes insulation or ballast for added strength, along with a hinged lid for secure access and a gasket for moisture prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional crawl space access system with concrete block walls and metal doors is constructed, then the structure provides basic access functionality, but it is costly, time-consuming to construct, and requires significant coordination of multiple construction phases
Solution Approach 1:
The access system is divided into separate functional components: a pre-formed plastic tub structure for the pit, a separate door assembly, and a cap structure. This segmentation allows each component to be manufactured independently and assembled quickly on-site, dramatically reducing construction time while maintaining structural integrity.
Solution Approach 2:
The plastic tub structure is pre-formed in a manufacturing process that includes integrated reinforcement ribs and mounting features. This preliminary action eliminates the need for on-site concrete pouring, curing, and multiple construction phases, allowing the structure to be installed as a single unit that provides immediate structural stability.
2Strength
If metal doors and concrete block walls are used in the crawl space access system, then the structure provides basic access and support, but the materials are prone to rust and material degradation over time
Solution Approach 1:
The system uses a composite construction approach: the tub structure is made from high-density polyethylene plastic reinforced with integrated rib structures, the door is constructed from pressure-treated wood with metal hardware, and the cap is made from rot-resistant materials. This combination of materials provides structural strength while resisting rust and degradation.
Solution Approach 2:
The design accepts that the door and cap are replaceable components that can be easily replaced if damaged or degraded. This approach uses simpler, more economical materials for these non-structural elements while maintaining overall system durability through the permanent tub structure.
3Strength
If the crawl space access pit is constructed with concrete block walls, then the pit provides structural support, but water can still infiltrate into the pit and the construction process is complex and time-consuming
Solution Approach 1:
The tub structure uses a molded plastic shell that forms a continuous, non-porous barrier against water infiltration. This flexible yet strong plastic construction provides both structural support and waterproofing in a single integrated component, eliminating the need for separate waterproofing measures required with concrete block walls.
Solution Approach 2:
The tub structure combines the structural strength of reinforced plastic with the waterproofing properties of molded polymer materials. This composite approach provides both pit wall strength and protection against water infiltration simultaneously.
4Productivity
If a pre-formed plastic tub structure is used instead of traditional construction methods, then construction time is reduced and material durability is improved, but the device complexity increases due to the integrated design
Solution Approach 1:
Multiple functions are merged into the single tub structure: structural support for the pit, waterproofing barrier, mounting surface for the door, and containment for backfill material. This consolidation reduces the number of separate construction steps and materials needed, increasing productivity despite the complexity of the integrated design.
Solution Approach 2:
The tub structure serves multiple purposes simultaneously: it provides structural support, prevents water infiltration, facilitates quick installation, and offers a mounting surface for the door assembly. This multi-functionality compensates for the increased device complexity by eliminating the need for multiple separate components.
Data Source
AI summary
A crawl space access device is capable of being placed in a below grade level crawl space entry pit, and mating with the below grade opening in a building wall. The crawl space access device includes a body member having a base portion restable on a horizontal surface of the pit. A side wall portion extends generally perpendicular to the base portion. The side wall portion includes a side wall opening matable with the below grade opening.