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Exterior Waterproofing for Crawlspaces

Exterior Waterproofing prevents water intrusion into a crawlspace. In order for a crawlspace to be completely waterproof, it needs to have protection from subsurface water for all of the below grade walls. All of this protection must span from grade level down to a depth deeper than the crawlspace floor.Lindsley Waterproofing uses state-of-the-art waterproofing materials—usually a 56-mil, pliable, rubber-like membrane to prevent wall penetration of water. Successfully blocking the sub-surface water from crawlspace walls is not enough. We can’t just ‘wish’ the water away. We must provide a means of getting rid of the water that has been blocked by the waterproofing materials. Otherwise water would build up outside the foundation walls. Water doesn’t stack very well so it usually finds its way to the crawlspace floor by going under the foundation. Disastrous floods can, and very often do, occur without a single drop of water penetrating the crawlspace walls. Waterproofing without drainage is destined to fail. You’d be better off having good drainage and no waterproofing!!! (A good roof isn’t even close to being waterproof but since it drains so well, there’s not a problem.) Crawlspace drainage is much more difficult—it has to be deeper than the crawlspace floor which is sometimes quite deep in the ground.


There are two methods of getting rid of the water that waterproofing has blocked from the walls—installing a gravity drain or installing a pump system. A gravity drain is a downhill pipe sloped away from the house. It’s often referred to as a ‘tail line’. A gravity drain is the preferred method but there must be a destination for this pipe, or pipes, well below the crawlspace level to which the water can flow. If there is no such destination on the property, the second method of water disposal is unavoidable—a pump system must then be used. Sometimes a pump system is opted for because it costs less and is easier to install.


Exterior Waterproofing & drainage is by far the best protection for a crawlspace. It’s used almost exclusively when houses are being built. However, in ‘retrofit’ situations—not-so-new houses with established landscaping, connected utilities, air conditioners, patios, decks, additions, garages, etc., Exterior Waterproofing can be at best impractical—if not close to impossible. 


For a less expensive approach to correcting a wet, flooding or excessively humid crawlspace, see Interior De-Watering


For more information and help determining if Exterior Waterproofing is best for your crawlspace, please contact us to schedule a FREE inspection and consultation.



Why Exterior Waterproofing for a Crawlspace?

Exterior Waterproofing not only prevents flooding but it also dries out and protects crawlspace walls from deterioration. Exterior Waterproofing also minimizes humidity inside a crawlspace because of the dry walls. Humidity in a crawlspace provides a haven for mold, mildew, & insects. 


Without the drainage that comes with Exterior Waterproofing, below grade water collects around the footings of a foundation. That will compromise the structural integrity of a house. This can lead to cracked footings, cracked foundation walls, and costly repairs. Exterior waterproofing & drainage will prevent water from damaging your home and can save you tens of thousands of dollars in the long run.


For more information regarding exterior waterproofing & drainage for your crawlspace, or to schedule a FREE inspection, please contact us.


The most common BAD ADVICE: “Your crawlspace will be dry if you fix your gutters, extend buried pipes for your downspouts, and grade the surface to slope away from the house.” Not really bad advice to do those things as long as it’s pointed out that those improvements won’t cure a wet crawlspace problem. Only when it’s suggested that doing the above will solve a water problem is it truly misleading advice. A false sense of security can have disastrous results. Without question every drop of water that’s diverted away from a house is a good thing. The above steps are a definite improvement. We do them all the time. Just don’t expect those steps to completely solve a water intrusion problem. Simple logic explains why it’s just not enough:


  1. If a crawlspace is getting wet, that automatically means that the in ground protection is failing. That would be a Waterproofing and/or a Drainage failure.

  2. Therefore, when the ground gets saturated, the failure(s) will be exploited.

  3. NO AMOUNT OF GRADING WILL STOP THE GROUND FROM GETTING SATURATED. (If a sloped surface kept water out of the ground, there would be no trees, or any other vegetation on the sides of hills or mountains.)


For more information and help determining if Exterior Waterproofing is best for your basement, please contact us to schedule a FREE inspection and consultation.


Since 1994 Lindsley Waterproofing has been Making Homes Healthy by providing expert waterproofing services to homes and businesses in the Research Triangle region of North Carolina. We can help you if you are in or are near Apex, Benson, Carrboro, Cary, Chapel Hill, Clayton, Durham, Franklinton, Fuquay Varina, Garner, Hillsborough, Holly Springs, Knightdale, Pittsboro, Raleigh, Rolesville, Roxboro, Selma, Smithfield, Wake Forest, Wendell, Youngsville, Zebulon, North Carolina. We repair and prevent structural water damage provide for new & existing structures. Our guaranteed services include de-watering, foundation repair, structural repair, fixing foundation leaks, waterproofing, yard drainage, french drains, crawlspace conditioning, helical pier foundations and ensuring that we help you to create a healthy home.

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