Prior to doing any serious work on the generator installation we needed to develop a foundation for it. This page outlines our project on this portion of the work.
We selected the north side of the garage for the generator site for a couple reasons. The first is that we rarely get more than a few inches of snow on this side of the house as the prevailing winds from the northwest blow it clear. Another reason is that the distance from the generator to the main service is fairly close and I can run conduit through the crawl space to the service entrance panel. The final reason is that we are told that although this is a quiet series generator by Generac, it does produce enough noise that we donít want it where the noise would drive us out of the house.
The generator is 2 foot by 4 foot and does not require any special foundation. But since we need to complete the landscaping on this side of the house we are planning on adding a short retaining wall along the 32-foot width of the garage and tie it into the existing retaining wall. We will include a planting area along most of the garage for shade plants and the generator will set on washed river rock atop the retaining wall. I began the project today by forming a 12-inch wide footing for the concrete retaining wall blocks. The blocks themselves are about 8 inches so this will leave a concrete apron at the base of the wall. We are including this detail so that in the future when we pour a driveway past this area we will not need to tear into this wall. The picture below shows the footing extending to meet the existing retaining wall.
While the concrete was setting I started removing the old Styrofoam sheathing we had applied to the foundation of the house. This material was not intended as a permanent finish and is starting to deteriorate. I also finished setting the LP gas line that I installed last week. This gas line was laid in a 50-foot trench that I dug by hand. It was a beautiful day to start this sort of project and the concrete was fully set by the time we cleaned things up.
The next step in creating the footing for the retaining wall is to use strips of hardboard siding ripped to 3-1/2Ē to create a gently curving area large enough to act as the base for the generator. This type of siding material is 16 foot long and makes a great form for lightweight use such as this. I also set a few retaining wall blocks on the new foundation to see how the transition from the existing wall to the new one would look.
Pouring this second section took a little over an hour and the weather was perfect for the work. We had a stiff breeze that cooled me off while I worked and the concrete set-up so that I cold get it finished before it got too late in the evening. While I waited for it to set I removed the Blue Rug Juniper shrub that covered the surface above the existing retaining wall. We are not sure if we are going to allow the shrub to grow back or take it out completely. But it was out of control for trying to work around the existing and new wall so it had to go.
The final form was fairly easy to set and is ready for the concrete. This form, when done, will allow the landscape blocks to end at the corner of the house. I set a few more blocks at the east end of the footing and took this picture to show how the lip on the bottom of the blocks anchors each row of blocks so they will not slide about.
The final concrete footing section is poured and I have added more retaining wall blocks to the wall. With this finished it is time to start hauling fill material to complete the planter/foundation.
We finished pouring the foundations and then moved on to stacking the blocks for the wall. We had a load of fill dirt delivered and we used about 3 yards of soil to fill in the planting areas. We used a rocky mix from a borrow pile to fill in under the foundation area for the generator so that we would not have any settling. The pressure treated lumber in the image above is the final foundation for the generator. It rests on two rows of concrete blocks that are held in place by the fill material. I will finish the wood foundation once the generator is in place. The picture below shows the completed planter area with a few plants and mulch in place. We will hold off on the rest of the mulch and planting until the generator is set, which is the next step in this project.