Site Preparation

The big day had arrived ... site preparation begins. We had visited the site, laid out the house in the grass, and discussed the project with Steve Johnson. Steve handles heavy equipment like sculptor chisels marble.

First thing was to scrape the vegetation off the building site so we could see what we were doing among the weeds. Steve make certain that he preserved what little top soil there was on our site. This will be used later when we contour the site for landscaping.

We did a soil test to determine the organic content of the soil, the ph and nutrient content, including micro nutrients. Our site had acceptable organic matter and was very high in iron. However, the soils are very sandy and thus the water holding potential is low. Soil ph was 5.4 on the top and 5.7 in the swale. Thus, later in our process, we plan to bring in humus to amendments the soil increase its water holding capacity and use lime to improve the ph closer to neutral. On balance the top soils tested very low for a number of micronutrients. Good humus can compensate for these short comings.

After we scrapped the site, we laid out the site again and began to cut down into the property to create a level building site. Additional fill material had to be brought in to complete the site preparation.

Ideally, more of the site should have been left for natural vegetation. However, given the landscape plan and the soil type, we opted to forgo BuiltGreen and LEED points on this item. While not the perfect site for a house, we have a great view and designed the house to follow the contour as best we could.

As fill material was brought in and compacted, a soils specialist monitored the process. Thurston County is in an earthquake prone area, so good soil compaction was a key requirement of the local building code.

Ours is a slab on grade construction one story home, so footings can be shallow. After the perfectly leveled site was prepared, Steve Johnson began to dig the footings along the lines we defined again. I believe that this was the 3rd or 4th time we laid out the house on the property.

Using a laser beam leveling tool to check, the trench for the footings were cut into the compacted site. Amazing to me how a good operator can dig a trench within 1 inch of level with a big back-hoe.

One final item ... erosion control. It rarely rains hard in the summer months in the Pacific Northwest. However, in the event that it did, Barrett made certain there was a silt fence to keep our top soil from eroding down the hill to our east into a mountain stream. This is simply common sense.

We welcome your comments on this site.
You can email Christine Garst at cbgarst@aol.com
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Sunday December 17, 2006 05:34 PM -0800