BASC Search | Building America Solution Center

This building foundation has a drainage layer located on the exterior of the waterproofing membrane.

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The sheathing has rotted because there was not a sufficient drainage gap behind the stucco cladding

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Traditional methods of site drainage, such as site grading, can be difficult to achieve on urban sites.

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A common method of addressing significant groundwater leakage in the foundation is to line the interior perimeter of the foundation with a drainage layer.

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Standard Specification for Manufactured Polymeric Drainage and Ventilation Materials Used to Provide a Rainscreen Function, ASTM E2925–19a

Reference

Specification describing criteria for manufactured polymeric materials used to provide a rainscreen function, a means for the drainage of liquid moisture and the ventilation of vapor moisture that enters an above-grade exterior wall assembly which was published in the year 2019, and is available for...

Right - This cedar siding is installed over furring strips which allow an air and drainage gap behind the siding.

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A common method of addressing significant groundwater leakage in the foundation is to line the entire foundation assembly, including the slab, with a drainage layer.

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A plastic fiber drainage mat rainscreen provides uniform support for the siding and allows moisture to flow horizontally and diagonally in addition to vertically.

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Right - The service penetration in the waterproofing membrane is well-sealed, and there is a drainage mat acting as a protective layer on the interior of the soldier piles and wood lagging.

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A liquid-applied water barrier covers the walls, serving as a drainage plane, air and vapor barrier, and secondary window flashing beneath the rigid foam that will be installed next.

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The builder installed a rain screen product that provides an air gap and drainage plane between the coated OSB sheathing and the cladding; the fabric layer folded over the bottom edge forms an insect screen.

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Below-Grade Water Management for Urban Sites

Guide

Guide describing methods to manage groundwater under and around urban multifamily buildings.

Stone Exterior Installation for Durability and Water Management

Video

Video describing how to properly install exterior stone on a house by providing a drainage plane to prevent moisture from infiltrating the wall assembly.

Temporary dry floodproofing wall design concepts

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Final Grade Slopes Away from Foundation

Guide

Guide describing how to properly grade a site so water will flow away from the foundation.

Water Management of Existing Crawlspace Floor

Guide

Guide providing information about treating bulk water drainage issues and moisture control measures in existing basements and crawl spaces.

Air Sealed, Insulated Basements

Guide

Guide describing how to insulate a basement to improve the overall thermal performance of the building and provide more dry, usable conditioned space for home occupants and HVAC equipment.

Managing Indoor Humidity and Ventilation in Cold Weather

Guide

Guide describing steps to take to minimize indoor humidity during cold winter weather.

Flooding Overview

Information Guide

Overview guide describing residential floodproofing steps.

No Vapor Retarders on Interior Side of Air-Permeable Foundation Insulation

Guide

Vapor retarder plastic should not be installed over fibrous insulation on basement or crawlspace walls; rigid foam or spray foam should be installed directly against the concrete, behind the blanket insulation.