InspectAPedia ^®

This article discusses options for sealing basement or crawl space floors and walls, or other building foundation walls to stop water entry and to reduce interior moisture and mold risks. See WET BASEMENT PREVENTION for a description of the critical steps to prevent basement water entry and foundation leaks. See Also see BASEMENT LEAKS Moisture or Mold for articles on diagnosing building water entry, and see CRAWL SPACE Dryout Procedures.

The photograph at page top shows a very wet basement foundation wall built of concrete block. The stain pattern extends high on the basement walls, down the full wall, onto the basement floor. Correcting this particular water entry problem should begin outside with roof drainage and surface runoff. This article discusses foundation wall and floor slab sealant options. .

© Copyright 2010 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

Basement Waterproofing Using Sealers for Concrete Floors & Masonry Foundation Walls

Aaron Kuertz, Applied Technologies, Inc.

Sodium Silicate Sealers for Floor & Foundation Wall Waterproofing

Sodium silicate is used in a water-based mixture to seal the basement walls and floors.  The sodium silicate penetrates up to 4” into the substrate.  After penetrating the sodium silicate reacts with the free lime content of the concrete or masonry .  Concrete, concrete block and masonry has lime as a natural component in their composition. 

This reaction between the sodium silicate and free lime produces a solid crystalline structure that fills the microscopic cracks and pores of the substrate.  This hardens and densifies the concrete and masonry so that water vapor and gasses cannot migrate through by capillary action.  Also, gasses are retarded from entering a basement.  After curing, the substrate looks the same as if it were not sealed.  There is no surface film or sheen to it.

Benefits of Sodium Silicate for Building Waterproofing

By sealing the basement walls and floors with sodium silicate water vapor will be stopped from entering into a basement.  The basement will be dryer than before.  This greatly improves the interior air quality of a home by retarding the growth of mold and mildew. 

Since the surface of the walls and floors are hardened, they will have less dusting and chalking.  Gas transmission will be reduced as well, further improving air quality.

Many people like to paint the floors and walls of their basements.  If paint is applied to unsealed walls and floors, it is possible for the water vapor to get trapped under the paint.  After a period of time the water vapor can break the bond between the paint and the substrate.  This causes the paint to blister and peel.

After application of a sodium silicate the walls and floors can be painted without fear of the paint peeling and flaking.  Also, adhesives for tiles or other floor coverings can be used.

Application of Sodium Silicate for Basement or Crawl Space Waterproofing

Sodium silicate is applied to bare concrete, concrete block or masonry.  Anything that would prevent the sodium silicate from being absorbed must be removed.  No grease, dirt, soil, adhesives, oil, sealer or paint can be on the surface to be sealed prior to application.

Application is done simply by using a garden sprayer, roller or brush.  First dampen  the surface with water using a mop or brush.  Apply in areas 10’ x 10’ in several light coats.  Apply each coat after 10-20 minutes.  Concrete takes 2-3 coats, concrete block and masonry 3-4 coats.  Do not over apply the sodium silicate since if all of the product is not  absorbed it may leave a white residue.  Wipe up any excess product.

For several days after application loose dirt will be pushed out of the substrate.  This is normal and can be swept off.

Share this Article      

...

Technical Reviewers & References

• InspectAPedia.com^® - Daniel Friedman
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

WATER ENTRY in BUILDINGS
  ATTIC LEAKS Moisture or Mold
  BASEMENT De-Watering Systems
  BASEMENT HEAT LOSS
  BASEMENT LEAKS Moisture or Mold
    Cold Pour Joint Leaks
    Form Tie Leaks
    Wall Crack Leaks
    Floor-Wall Joint Leaks
  BASEMENT WATERPROOFING
    BASEMENT DE-WATERING SYSTEMS
    EXTERIOR WATER SOURCE ELIMINATION
    FOUNDATION DRAINS & FRENCH DRAINS
    FOUNDATION WATERPROOFING
    GEOTEXTILES & DRAINAGE MATS
    SEALERS, Basement Floor & Wall Moisture
    SITE DRAINAGE
    SUMP PUMPS GUIDE
    WINDOW LEAKS INTO BASEMENT
  WET BASEMENT PREVENTION
  CRAWL SPACE Dryout Procedures
  DEW POINT CALCULATION for WALLS
  DEW POINT TABLE - CONDENSATION POINT GUIDE
  EFFLORESCENCE, Salts & White / Brown Deposits
  FLOOD Damage Assessment & Repairs
  FLOOD DAMAGED FOUNDATIONS
  FLOOD VENTS
  FLOODS IN BUILDINGS-priorities
  FOUNDATION WATERPROOFING
  HUMIDITY CONTROL & TARGETS INDOORS
  HOUSEWRAP AIR & VAPOR BARRIERS
  LOG HOME Leak Diagnosis & Cure
  LOG HOME Condensation &Moisture
  MOISTURE CALCULATIONS
  MOISTURE PROBLEMS: CAUSE & CURE
  MOLD in BUILDINGS
  SEWAGE CONTAMINATION
  SUMP PUMPS GUIDE
  WET BASEMENT PREVENTION
    Wet Conditions - Foundation Collapse
    Living With a Basement that Floods
    Steps to Prevent Basement Water Entry
    Soil Testing
    Water Entry Priorities
    True Foundation Waterproofing
    Foundation Footing Drain Details
    Foundation Drainage Backfill Details
    Finish Grading
    Repairs Cure Basement Leaks

• Aaron Kuertz is with Applied Technologies, Fairfield, OH  45018, 877-APPLY-IT (277-5948). (513) 939-3767. Mr Kuertz has been in the waterproofing industry since 1998.  Applied Technologies is a manufacturer of waterproofing products used by both professional contractors and homeowners alike.  For more information on Hydra Block™ water-based concrete and masonry penetrating sealer used for concrete and concrete block basement sealing, see Applied Technologies at www.appliedtechnologies.com

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• More Reading about Dealing with Attic Mold, Identifying, Removing, and Preventing Mold in Attics

  Be sure to review HOW TO FIND MOLD: How to Inspect Homes and Other Buildings for Mold - the Basics of How to Find Problem Mold Indoors in our Mold Action Guide. Here are other articles that will be helpful in evaluating attic mold presence, causes, and cures:

  • What Mold and Allergens Look Like: mold identification photos to help identify mold - choosing what to sample in buildings
  • How to Clean Moldy Wood Framing & Sheathing How to clean/seal mold from/on exposed lumber or plywood subfloor or roof sheathing indoors - some suggestions based on our field and laboratory research
  • Lighting, proper use of: proper aiming of a good flashlight can disclose hard to see but toxic light or white mold colonies on walls.
  • Mold spores in the Home - a Photo ID Library for detection and identification of mold allergens.
  • How to Find and Test For Mold in Buildings A "how to" photo and text primer on finding and choosing the right spots to test for mold in buildings
  • 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.
  • Simple Adhesive Tape Sampling of Moldy Surfaces - how to send a mold sample to our lab
  • Mold Sampling Methods in the Indoor Environment - In-depth article: detailed critique of popular mold testing methods - Is your mold test kit worth the bother?
  • Humidity: What indoor humidity should we maintain in order to avoid a mold problem?
  • 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.
• ...

More Information on Building Diagnostic Inspections and Repairs

...

InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

Contact Daniel Friedman for website content suggestions or for fee-paid consulting