Living in Yellowknife

Maintaining a Trailer in Yellowknife: Part 2 – Foundation

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

Trailer Series:

Maintaining a Trailer in Yellowknife: Part 1 – What is a Trailer?
Maintaining a Trailer in Yellowknife: Part 2 – Foundation
Maintaining a Trailer in Yellowknife: Part 3 – Pipes


About the author

Kyle Thomas

Kyle grew up in Yellowknife and is a local entrepreneur, writer, baker, and Yellowknife Advocate who is addicted to learning as much as he can about the community and sharing it with anyone who'll listen. In 2009 he developed A website all about living, working and thriving in Yellowknife for residents, newcomers, and visitors.


  • Thank you for all the information. We learned a lot, Just wondering how easy is to find houses on steel pile foundation?

    • It isn’t too hard. Generally, there are specific developments that have steel piles, or areas of town. Most real estate websites will list the foundation that a particular trailer is on – either wood blocking/cribbing or steel piles. If there is a trailer that is on wood blocking that you are interested in I wouldn’t completely shy away from it. Some questions to ask would be – how often has it been levelled (how much shifting happens), what is the quality of the wood blocking (pressure treated, on concrete slab – off the moist ground), how well was the area developed (are you on soft ground over a swamp), and how much ground clearance is under the house to do any maintenance (3-5 feet is a whole lot better than just a foot). Our trailer is on wood blockings and we haven’t had any shifting over the 6 years we’ve owned it. Hope this helps.

  • Any idea which companies level modulars? I have been looking around and having trouble finding any help.

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