In my last post about maintaining a trailer in Yellowknife, I introduced you to what a trailer is, where they are around Yellowknife and what we’ll be doing with this series.
So let’s get into the series and talk about the foundation of a trailer, which is something you should know about before purchasing a house.
The big question: Steel Piles or Wood Blocks?
Trailers don’t have concrete foundations. They are built above ground to make installation easier. The two types of trailer foundations are Steel Pilings and Pads and Wood Blocks.
Steel Piles are widely praised as the better solution because the piles are driven into the ground and bonded to the bedrock where there won’t be subjected to frost heave. They are much easier to maintain, but often houses on steel piles are slightly more expensive.
Pads and Wood Blocking sometimes referred as Engineered Wood Foundations, are the easier and not as expensive solution when installing a trailer. It is a cheaper route for a developer. Wooden block cribs are placed on pads and then the trailer is placed on the blocks. The issue lies with the soil condition under the trailer and the resulting seasonal shifting of the ground due to permafrost. As the ground shifts so does the trailer. This is why trailers on wood blocks often have to get ‘levelled’ regularly, sometimes as often as every couple years.
Levelling a house is much like getting your furnace serviced, it just takes longer. There are several contractors in Yellowknife who offer the service. They come in, jack up the trailer where needed and shim it to level it. The act of jacking and shimming might sound easy enough but moving around and understanding how the trailer will move is a skill of its own. I’m over simplifying it in this post.
When buying a trailer on wood blocks always look at how much room is between the ground and the bottom of the trailer. A contractor will have to crawl under there to level the trailer. The more room, the easier it is. Trailers from the 60’s and 70’s often have very little room.
When looking at the wood blocking under a trailer it is important to look at the amount of water, wet ground and high humidity in the crawlspace. Water is the source of many problems in houses. Wood, especially if it is not pressure treated will rot when exposed to wet conditions. Note if the blocks are pressure treated. These all factor into longevity of the foundation.
Some people won’t buy a house on wood blocks at all but since half the trailers in Yellowknife are on wood blocks I don’t see this as an issue. What I would look at is the history of the house. How many times has it been levelled previously? This might indicate how often you’ll have to do it in the future. This is why getting a pre-purchase home inspection is important. Not only will you have a knowledgeable person reviewing the house with you but they may also have historic data on the home.
Did we miss something? Send us a message and let me know.
This series is in part supported by Housecheck Yellowknife. Didier Bourgois of Housecheck Yellowknife provides pre-sale and pre-purchase home inspections as well as consulting services. Check out his website at housecheckyellowknife.ca