Basement flooding is not always what it seems, a visual guide Paragon Home Inspections Evanston / Chicago

Homeowners often assume that flooded basements and crawl spaces like this one are the result of underground seepage through the foundation wall and floors, and assume that expensive "basement waterproofing" will be necessary to correct such problems. The inspection of this property identified a number of much less expensive steps that could be taken to reduce and perhaps even eliminate water problems.

Wet basements and crawl spaces are a frequent cause of homeowner distress, and a majority of the basements we see at home inspections in Chicago and many suburban areas show at least some evidence of current or previous seepage or flooding.

Correcting such problems can be expensive, and it's not possible to be sure that water problem once fixed will not reoccur as a building settles and the foundation walls are stressed over time

Fortunately. at the majority of properties we inspect with wet basements and crawl spaces there are inexpensive initial steps that can reduce and sometimes even eliminate such water problems.

The article will outline some of them, using an actual inspection as an example.

The crawl space in the picture above was located below this typical Chicago style ranch home in Wilmette IL. The home inspector's initial impression from the curb was that the house appeared to be well maintained, and the client probably expected to receive to relatively "clean" report on the property's condition.

The first indication that there might be a water problem was found at the exterior - there were no gutters or other water control methods where the roofs met at the junction between the main structure of the house and an addition at the rear.

The water flowing off the roof at the bottom of the valley had go somewhere, and in this case it went down the wall of the building and then flowed along the foundation.

With this in mind, lets go back and take another look at the crawl space, paying special attention to the area near the gas meter in the picture above.

Now that we know where to look, a wet area of the crawl space wall is apparent at the interior opposite the gas meter.

The next step is to confirm possible water entry at this point by closer examination of the foundation wall in this area. If the wood structure above the foundation has an elevated moisture level it's a strong indication that we have identified the source of at least some of the water in the crawl space.

At this point the inspector knew that the potential purchaser would have to budget for a substantial expense to repair this damage, a problem which could have been prevented by the thoughtful design and installation of less than a hundred dollars worth of flashing and downspouts to properly dispose of water flow off the roof.

We could stop at this point... but this house still has some things to teach us. top

Downspout too close to foundation and wet location, water is being directed back toward flooded crawl space

This downspout is on the same wall which is receiving water from the valley, you can see it's location in a wider context it in a picture above to the right of the ladder.

The picture to the left is one of the most mundane in home inspection - in our area some version of it probably appears in two thirds of the reports written on single family homes.

This belies the fact that it's also one of the most important items on many reports - in many cases relocating downspouts on buildings with wet basements or crawl spaces can largely or even completely eliminate such problems.

The reason why downspout placement is so important is well illustrated by this example - the darker material below and to the left of the downspout indicates that downspout discharge is backing up behind the paving blocks and is being held against the foundation wall

If a flaw in the foundation wall can admit moisture, or if the wet soil is rises above the foundation wall and water can enter between the foundation wall and the structure above, the water saturated soil will provide a path for water from the downspout's discharge to the interior of the basement or crawl space.

If you have such downspouts and also have basement or crawl space water problems, then improving downspout discharge locations is the logical place to start attempts to reduce moisture in a basement or crawl space.

Given the expense and annoyance resulting from wet basements, and the often easy and inexpensive downspout improvements that can often cure them. such improvements are often the most cost effective suggestion in an inspection report.

Downspout discharging onto improperly pitched (sloped) driveway is directing water back toward flooded crawl space

An attempt has been made to seal the junction of the siding to the driveway with caulk. Not only is the seal unlikely to be watertight, but any moisture behind the caulk will be held against the wall and cracks in the caulk provide a hidden mode of entry for insects.

On the opposite side of the building it was even more difficult to provide for proper disposal of downspout runoff as the downspout discharged onto a driveway which did not have sufficient pitch away from the structure. As a result water was running around the corner and next to the foundation.

In such cases it is necessary to relocate the downspout's discharge to a more acceptable location.

Often the easiest way to relocate the discharge is by moving the downspout to a different location on the gutter and re-pitching the gutter downwards toward the new downspout location.

When this is not possible, the downspout can be connected to the municipal sewer system (forbidden by some building departments), or to a underground pipe discharging at a more acceptable location, or to the a foundation drain system or a "French Drain".

Some of these alternatives are expensive, but they will likely be considerably less expensive that an effective basement waterproofing or foundation drain system.
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Finally, for a more complete perspective on the water problems at this property, we need to pull back for a wide view of the addition and back yard:

The homeowners have built a paving block patio across the entire back yard alongside the drive way, but they have neglected to provide sufficient pitch away from the house, and in paving over the entire yard have left little bare ground to absorb direct rainfall or water from the downspout discharging onto the driveway at the corner just beyond the right edge of this picture.

Unfrotunatly, there is often no way to improve this type of defect without removng the pavers, correcting any defects in the stone base layer, and reinstalling the patio at a correct pitch and with attention to where water flowing off the patio will run. top

We can't know in advance of trying if correcting the defects above will solve the water problems in this basement.

But we do based on experience that correcting such defects can often make a dramatic difference is such situations, that some of these repairs and improvements (for example extending downspouts) can preformed by homeowners in a single afternoon, and that many of the corrective actions suggested above will be much less expensive than "waterproofing" a basement and/or installing or improving interior or exterior foundation drain systems.

For these reasons identifying and correcting such problems is our general recommendation as a first step in diagnosing and solving water problems in basements and crawl spaces. top

Home Inspection Notes: Basement Flooding Isn't Always What It Seems