water ingress

Unfinished Basements and Crawlspace Inspection

Routine Preventative Maintenance for Unfinished Basements and Crawlspaces

If your home has an unfinished basement or crawlspace, a good preventative maintenance activity after winter is to check it for water ingress and look at the systems visible therein (plumbing – waste and piping, heating ducts etc).  Houses that are built on hillside lots, or those built on flood plains or close to water sources, are particularly vulnerable.

If your downspouts discharge above grade, pay attention to inside the crawlspace or basement adjacent to where they discharge on the exterior.  To prevent water ingress, it is recommended that downspouts that discharge water above grade should do so 4 – 6 feet away from the house. Look for damp areas.  A building scientist once told me that 90% of wet basement and crawlspaces are caused by poor control of surface water.

water ingress unfinished basement

The photograph above shows water ingress caused by a downspout that discharges above grade and too close to the house.  Due to a lack of preventative maintenance, this had caused the sill plate of the wood frame of the house to rot. Always remember, preventative maintenance will save you money in the long term.

In older houses, if they are fitted with a perimeter drainage tile, it is recommended that these are checked annually with a CCTV camera to ensure that they still functioning and are not broken or blocked.  Tree, plant and scrubs roots can invade drainage tiles in their search for water. Most plumbing contractors offer this service at reasonable cost. Black corrugated plastic and old cement drainage tiles can be prone to failure.

Cracks in foundation

Finally, check the foundation walls for cracks.  If you know your foundation walls already has these, check to ensure that they have not changed.  If they have been subject to repair, check that the repair is still good.

Most cracks in foundation walls are not serious, but if present, monitoring for changes is recommended.  The example below shows a typical minor crack. Anything else should be repaired.

minor crack found in house inspection

The photograph above shows a typical minor crack.  The foundation is not on an exposed position and there is no evidence of water ingress or differential settlement.  The 12” rule is used for scale. The crack is below 1/8” wide. This type of crack should still be monitored in case it changes.

However, here is a summary of what to look out for with cracks that require further specialist evaluation (foundation repair specialist).  This list is not exhaustive.

  • Any horizontal crack.
  • Cracks that show differential settlement (see photographs below)

foundation crack half inchFoundation crack – ½” wide  

foundation crack side view Same crack ¼” difference in vertical face

In the example shown above, the house was on a steep hillside lot with a watercourse below.  There was a similar crack on the diagonally opposite foundation wall. Combined factors suggested that the corner of the house had moved.  This is a good example where advice of a structural engineer and foundation repair specialist should be sought. It is likely that the foundation will require underpinning.  In a pre-purchase home inspection, this should be completed prior to subject removal so that you are aware of the cost of remediation before you commit to the deal. This crack was found in a crawlspace 16” high.   It’s a good example of why you should employ a professional licensed home inspector.  

  • Cracks that are wider at the top than at the bottom
  • Cracks wider than 1/8”

Other routine checks that can save you money

The basement and crawlspace areas also provide access to check the plumbing for leaks.

          evidence of waste pipe leak in basement             Waste pipe – evidence of leak

rot from pipe leakRot to surrounding sub floor

The above example again shows the benefits of regular preventative maintenance. The leak could have been spotted earlier, before rot occurred.

So, get into your unfinished basement or crawlspace and have a look around.  In the vast majority of circumstances, nothing will have changed. But if you do notice anything unusual, the chances are that you will have caught the problem before it causes major problems.  That’s the whole purpose of preventative maintenance.

Contact House Sounds Home Inspections

If you are unsure about the state of your basement or crawlspace, click here to contact Mark or Gerrie Goodwin with House Sound for a thorough and professional home inspection.

Learn more about the home inspection services:

Call 604-389-9556 , or email for a home inspector now!


See What Customers Say about House Sound Home Inspections