Managing Humidity, Moisture & Mold in a Mongolian Yurt

Mongolian yurts, better known as Mongolian gers, are gaining popularity as sustainable and versatile alternative housing options in Canada, the United States (USA), and the rest of the world. However, due to their unique, organic construction and materials, yurt dwellers in high-humidity areas may face challenges related to moisture. 

In cold regions, combating humidity issues in permanent yurt homes can be challenging. That’s why we will be highlighting how to utilize the natural features of the yurt, as well as make slight modifications to control humidity. Yes, even in the North American east and west coasts, as well as Alaska and other northern states and provinces. 

This article will explore practical tips to prevent these issues and ensure a comfortable living environment in your yurt, including:

  1. Site Selection
  2. Foundation and Flooring
  3. Insulation and Ventilation
  4. Layer Modifications
  5. Air Conditioning (A/C), Dehumidifiers and Fans
  6. Storage
  7. Maintenance and Care
  8. Mold Removal

1. Site Selection

  • Choose a well-drained location with good air circulation to prevent moisture buildup around the yurt 
  • Avoid placing the yurt in low-lying areas or near water sources where water may accumulate. 
  • Place your yurt in a well-ventilated area to ensure sun and wind exposure. Open grassland is preferred over the midst of a forest. If you’re concerned about wind in any open area, check out our article about how yurts withstand wind and ask us about our wind kits. 

2. Foundation and Flooring

  • Use a raised platform or foundation to elevate the yurt off the ground, reducing moisture from the soil.
  • Optionally, install a vapour barrier between the flooring and the ground to prevent moisture seepage. 

3. Insulation and Ventilation

  • Ventilation is key to prevent moisture accumulation and especially condensation.
  • Proper insulation can help regulate indoor humidity levels and prevent condensation. All our yurts include 1 layer of wool felt insulation, but more can be purchased based on your needs. Among the many natural properties of wool felt, its capacity to retain and later release humidity is a great one to help deal with condensation issues.
  • Air circulation can be improved by opening the Urgh, doors and windows, and by rolling up the sides of the yurt, 2 ft from the bottom with ropes.
  • Add mesh/mosquito netting to the toono (centre dome) if you’re worried about bugs while creating cross-ventilation. This can be done yourself, or we also offer custom-fitted mosquito netting that can be secured from the inside of the yurt using velcro. 
  • An additional solution that may require some expertise is creating custom vents by cutting out panels in your door and putting them on hinges, or by adding vents to your platform. 

4. Layer Modifications

  • Install a layer of house wrap between the felts and canvas to keep the yurt waterproof and reduce the risk of condensation by allowing it to breathe. We use Mento 1000, but the TYVEK brand produces good results. 
  • Be sure to regularly remove snow from the roof to prevent it from thawing and freezing, which can prevent the outer layers from breathing. 

5. Air Conditioning (A/C), Dehumidifiers and Fans

  • Some customers have recommended using small air exchangers, solar fans or dehumidifiers for additional ventilation.
  • A ceiling fan can also be helpful, in particular, if you use in-floor heating.
  • An A/C unit can also help manage humidity levels in hot months. Many customers connected to the grid have successfully implemented mini-split units (or heat pumps) that have multiple advantages including heating and cooling abilities, humidity management, easy implementation, and economical operation - especially in the compact and well-insulated volume of a Mongolian ger. It is also a good idea to add a ceiling fan to circulate the warm and potentially moist air that accumulates near the ceiling.
  • Store firewood outside the yurt to prevent excess moisture. It’s important to note that wet shoes, drying wood, drying clothes, etc. are all sources of humidity that will accumulate in the felt before evaporating through the canvas.

Note: After 2 weeks of heavy rains, a very small, continuous drip of water on an improperly sealed chimney (the water evaporated almost instantly) managed to saturate the felts, resulting in humidity stains and drips from the ceiling. It was fixing this small leak and ventilating while heating that solved the issue in hours. 

6. Storage

  • Take the yurt down and store it in a dry place if you’re going to leave it unattended for a long period, especially during humid seasons. 
  • If you choose to leave it up unattended, consider installing a solar fan in the ceiling, with the exhaust vented outside past the urgh (insulated top flap) using a vent conduit. Add extra supports for snow load and keep your circling ropes or straps tight!

7. Maintenance and Care

  • Check the yurt for leaks or wet spots, especially around the roof and walls. Water or brown humidity stains around doors, windows, or elsewhere on the inside envelope can be caused by water infiltration or, more often, condensation. If you suspect water infiltration, try to identify and fix the source right away. If condensation is the cause, take steps to manage the moisture and improve ventilation. Find more maintenance tips here.
  • Condensation from the roof often accumulates above doors and windows (instead of continuing down the walls and dripping outside). Make sure the house wrap is not completely sealed in those areas (this is contradictory to some of our earlier set-up videos for doors and windows, but reflects new learning on our part of what works best).
  • To reduce humidity production, ventilate the yurt when cooking, bathing, or while large groups of people are gathering inside. Again, VENTILATION IS KEY!
  • If you see humidity spots or feel that condensation is accumulating under the house wrap and/or outer canvas, remove snow off the roof, open the toono, and start a fire in the stove until it dries out.
  • Check the caulking at the base of the door and windows, and re-caulk if necessary. You can also re-caulk around the panels that form your door. If water gets trapped there, the door is more likely to swell. An extended awning is a good idea to divert water off your door and door step. We can help source awning extensions for those who can't find the right material.
  • We recommend that the wood parts of the yurt that are exposed to the elements, such as the door and the toono, be varnished with a marine-grade exterior varnish at least once a year.
  • Repair any damaged or worn-out insulation to maintain effectiveness.

8. Mold Removal

  • If you notice green patches on your exterior canvas, don't panic! What looks like mold may actually be algae or lichen, particularly after long periods of damp weather. These can generally be cleaned from the exterior canvas. Interestingly, lichen growing on the outside of the canvas isn't necessarily damaging the material and may be more cosmetic than harmful. The bigger concern is persistent moisture within the yurt's layers, which is where ventilation comes in.
  • If you’ve noticed stains or mold, try to gently pressure wash, and/or spray the areas and brush with bleach or vinegar solutions. Be sure to avoid canvas patterns and felts with the cleaning solution.
  • For a natural antifungal recipe, use 300ml of white vinegar, 200ml of water and 5 drops of essential oil (optional).
  • Brown humidity marks on the inside liner will disappear if you spray vinegar or bleach directly on the stains.

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Final Notes

Living in a Mongolian ger can be a rewarding experience, but it's essential to take steps to prevent moisture issues, for both the health of the yurt and its inhabitants. By following these easy tips, you can create a comfortable and healthy living environment in your yurt, whether you are in Canada, the USA or elsewhere. Make sure to carefully consider the best heat source for your yurt to keep moisture levels in check and enjoy a cozy living space year-round.  

For any questions, concerns or additional information on managing humidity, in a Mongolian ger, please don’t hesitate to contact us!