The Wise Man Built His House Upon a Rock

You may not know this children’s bible song.  It talks of a wise man building his house on a rock, and a foolish man building his house on the sand.  When the storm comes, the wise man’s house stands firm, and the foolish man’s house is washed away.  One of the best pieces of advice I can give to somebody considering a new home build is this – know the soil you are building on.   It is vitally important to understand how the soil behaves beneath your house foundation.  Additionally, the location of groundwater and its impact on the build is something you need to know in advance.  Sometimes the largest unexpected increase in project expense is surprise soil and groundwater conditions.  This is near and dear to my heart since I happen to be a licensed professional geotechnical engineer.  Studying the soil, bedrock, and groundwater conditions and selecting an appropriate building foundation is what we do. Hiring one of these specialized engineers is well worth the money.

We selected the location of the building pad based on a variety of priorities.  The view is spectacular.  It overlooks a small, spring-fed pond full of brook trout.  The view beyond the pond captures a massive rock ridge which gently descends and gives way to the untouched beauty of the Roosevelt National Forest.  The view is unobstructed by anything man-made.

Our next consideration was privacy.  We wanted elbow room, so we designed and built our own road into the building pad area.  It is accessible by ourselves and one other landowner which we happen to get along with fabulously.  The road leads into a gentle meadow area that is surrounded by  impressive pine and fir trees along with granite rock features.  The granite rock ridge provides a nice shelter from wind exposure, and provides an impressive view in the direction opposite the pond.    The large meadow is one of our favorite things about the site.  It contains hundreds of species of wildflowers.  There are more varieties of wildflowers than one can imagine. When the spring bloom begins, the colors are quite impressive, captivating us and enticing our honey bees.

Fire danger is a real risk out here in the arid west climate.  We located the building pad with considerable consideration given to the risks of fire.  One of the core philosophies of the local volunteer fire department is they will help those land owners who help themselves.  We selected our site such that there are no trees within 75 feet of the structure.  Also, the road provides easy access for first responders.   Our site would be an access priority due to the easier defensibility of the assets.

I mentioned earlier that I am a geotechnical engineer, and I began this blog by extolling the virtues of obtaining a comprehensive geotechnical investigation for your build site.  You would think this would have been the number one priority for me.  Well it wasn’t.  It ended up being an afterthought.  We wanted what we wanted (view, privacy, shelter, defensibility, etc.), and I was confident the soil was going to be risk free based on the nearby granite outcroppings.   I drilled a test boring in the middle of the pad area, and as it turns out, the location I selected had the worst soil on the property.  It was in a geologically young slope wash that contained loosely consolidated sand that was deposited by a large drainage feature.  It was extremely loose soil to about 19 feet.   In an attempt to manage foundation settlement to less than an inch, we had to over-excavate and replace 8 feet of engineered fill below the finished slab elevation (5 feet below the footings).  If we had not performed this soil remediation, the settlement would have likely exceeded 5 inches, and the differential settlement would have caused much damage throughout the log structure.  We could have moved the pad location to an area with better soil, but it would have been a trade off with our other priorities.  We get one shot at this, and our thinking was to pay for the soil remediation so we could have a nicer legacy to pass on to our kids.

Placing and compacting the engineered fill.
Over excavation and backfill with engineered fill
8 foot over excavation
Let’s dig some s*!t!

 

 

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