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Prevent future crawl space water entry by crawl space waterproofing methods:
How to keep water from entering a building crawl space in the first place.
Here we summarize the approach to preventing water from leaking into a building crawl area. The place to start is with an outside inspection for sources of leaks into the crawl area, but we also discuss using a sump pump to lower the water table under and around the building.
How to Keep Out Crawl Space Water & Moisture - Exterior Measures for Crawl Space Moisture Control
We noted earlier that it is almost always preferable to keep water from entering a building rather than allowing it to enter and then working to get rid of it. Here we refer to articles giving more detail on measures to keep unwanted roof runoff or surface or even subsurface water from entering a basement or crawl space.
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Inspect the roof drainage system, gutters and downspouts to be certain that roof spillage is not ending up by the building foundation.
Defects in handling roof runoff is the number one source of basement and crawl space dampness and water entry.
Start outside the building: inspect the building roof drainage system and surface grading to be sure that roof runoff is not spilling where it is trapped against the crawl space foundation walls.
The articles listed just below provide ample detail for more complete water entry source, cause & cure investigation for a crawl space.
Key building water entry diagnosis and cure articles:
SUMP PUMPS GUIDE - how and where to install a sump pump as an emergency backup against basement or crawl space flooding
WATER ENTRY in BUILDINGS catalogs all of the steps you should consider in keeping water from entering a building basement or crawl space. Just about every step you would take to prevent basement water entry applies to preventing crawl space water entry.
In a crawl space where there is standing water, dehumidification and dry-out efforts will be ineffective. We need first to get rid of standing water and second (as discussed previously) keep water from entering the crawl area.
It's always better to keep water out of buildings than to let it come in and then try to get rid of it. But some building sites and conditions may still justify one or more sump pumps in the crawl space. Earlier we stressed the importance of making sure that the crawl space floor drains to one or more points where as sump pump can be installed if needed.
Not like this! We cannot show all of the ways to foul up a sump pump installation in one article, but our photo at left is particularly disgusting. Don't just throw a sump pump into a low area in the floor. The resulting lake will continue to damage the rest of the building.
A sump pump can, by lowering the water table under a crawl space floor, reduce the chances of water entering the crawl space through the lower foundation walls or floor. We have used this method with success in areas of seasonally wet soils, but we would not add a sump pump installation to try to dry out a crawl area (or basement) before first fixing all outdoor water entry sources possible.
Otherwise you may find you are simply cycling water: pumping it out of the crawl area only to have the same water cycle back into the structure.
At SUMP PUMPS GUIDE we discuss types of sump pumps and how they should be connected to electrical wiring and to drainage destinations. Keep in mind that the time you are most likely to need a crawl space sump pump is during hurricanes or tropical storms or in northern climates during times of heavy snow melt.
During a storm is just when electrical power may be lost. If your electrical power is not reliable you should consider a battery-operated backup sump pump system with enough capacity to keep the pump(s) running until power is restored.
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 Harriet Burge, Harvard School of Public Health, and EM Laboratory, a private mold and environmental testing lab - email to D.F. August, 2004. Dr. Burge is an educator, writer, and consultant in the field of indoor air quality and mold contamination.
 Product literature and MSDS sheets for the biocides and fungicidal sealants listed in this article.
 US Centers for Disease Control, CDC: www.cdc.gov/ncidod/diseases/hanta/hps/ describes the risks associated with hantavirus.
 International Residential Code, IRC Section R408, Under Floor Space, http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_4_sec008.htm, retrieved 3/2/2013
See IRC Section M1305.1.4 [PDF] Section M1305.1.4 for access requirements where mechanical equipment is located under floors.
 International Residential Code, IRC Section R406, Foundation Waterproofing and Dampproofing, http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_4_sec006.htm, retrieved 3/2/2013
Thanks to reader C. Brown for suggesting the need for detail about rapid dryout procedures for a wet crawl space
Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
Humidity: What indoor humidity should we maintain in order to avoid a mold problem?
Stuff that is not mold but is often mistaken for it - things you may not want to test. Also, not all "black mold" is toxic - here are examples of harmless black mold.
Mold-Resistant Building Practices, advice from an expert on how to prevent mold after a building flood and how to prevent mold growth in buildings by selection of building materials and by anti-mold construction details.
"Weather-Resistive Barriers [copy on file as /interiors/Weather_Resistant_Barriers_DOE.pdf ] - ", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Asbestos: How to find and recognize asbestos in buildings - visual inspection methods, list of common asbestos-containing materials
Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on ASBESTOS, ITS INDUSTRIAL APPLICATIONS, ROSATO 1959, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print).
Asbestos Identification and Testing References
Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone
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