It's said that people sweat about a cup's worth while sleeping. Furthermore, Japan's high humidity means many are concerned about moisture accumulating in mattresses and futons, and about mold prevention.
When searching for "beds resistant to humidity," "slatted beds" often appear at the top. While they are perceived to have good ventilation and many benefits, they actually have drawbacks too.
This article will introduce the disadvantages of slatted beds and ways to mitigate them. By understanding the issues with slatted beds before purchasing, you can achieve comfortable sleep.
Do Slatted Beds Have Disadvantages?
A slatted bed has a base made of "slats" (簀の子) which are boards attached to cross-beams with gaps between them. Air can circulate through these gaps, providing excellent ventilation. This allows moisture absorbed by mattresses and futons to escape easily, making them less prone to mold and perfect for Japan's humid climate.
Let's look at the disadvantages of slatted beds, which are often thought to be resistant to humidity.
1: Firm Sleeping Surface
Many slatted beds can be used with either a mattress or a futon, but the slatted structure tends to make the sleeping surface firm. If you're using a futon, choose a thick one. A thin futon might feel too firm and uncomfortable. It's recommended to pair it with a mattress, where thickness isn't a concern.
2: May Lead to Back Pain or Stiffness
Slatted boards are harder than tatami mats or mattresses. If you combine a slatted bed with a thin futon, it could potentially strain your lower back or back muscles. Continued use carries a risk of developing or worsening lower back pain or stiffness. Therefore, caution is advised for individuals who already suffer from back pain, those with larger builds, heavier individuals, and the elderly.
If you experience back pain or stiffness upon waking, consider using a mattress instead of a futon.
3: Cold in Winter
While the high breathability of slatted beds is a great advantage for summer heat, humidity, and mold prevention, it becomes a disadvantage in winter.
Because of its excellent ventilation, cold air constantly circulates through the gaps between the slats. If your slatted bed is in a room with hardwood floors, the cold from the floor can transfer directly to the bed. To block the cold air, place a rug or carpet between the floor and the slatted bed, or switch to a thicker mattress.
4: Creaking Noises
Slatted beds have a distinct creaking sound due to the slat design and wood, which new users might find bothersome. Futons don't have much elasticity, so weight transfers directly to the bed, making noise more likely.
Pairing it with a highly cushioned mattress can help reduce the bothersome creaking sounds.
5: Odor from Adhesives or Paints
While this issue is more common with relatively inexpensive products, you might notice an odor from adhesives or paints, separate from the natural wood smell. In such cases, wipe it thoroughly with a damp cloth, then a dry cloth, and air it out completely in the sun. Be careful, as leaving moisture can lead to mold.
6: Mold Can Still Occur
Even though slatted beds have good ventilation, mold can still occur if you leave the futon on the bed or reduce how often you air it out. While they are undoubtedly more resistant to moisture than regular beds, the areas where the mattress or futon directly touches the slats (excluding the gaps) are similar to a regular bed. Therefore, it's important to regularly air out your mattress or futon and frequently wash your futon covers.
If you can't commit to frequent care, it's recommended to use a breathable fiber mattress that is less prone to mold.
Slatted Beds Also Have Many Advantages
Slatted beds, characterized by their high breathability, also offer numerous benefits.
- Less likely to trap moisture, helping prevent mold in mattresses and futons.
- Easier maintenance for mattresses and futons.
- Good ventilation keeps you cool even on hot and humid summer nights.
- Can be used with both mattresses and futons.
- Some foldable slatted beds allow you to fold them with the futon still on.
Consider the pros and cons, and whether to incorporate one into your home based on your lifestyle, existing bedding, and sleeping environment.
Materials for Slatted Beds
Slatted beds come in various materials, each with unique characteristics.
Hinoki (Japanese Cypress)
A famous material that Japan boasts to the world. Its unique aroma and beautiful luster are popular, and it's highly resistant to moisture and water. It is a valuable material widely used as high-grade building material, as well as for fittings, furniture, joinery, and bentwood items.
Sugi (Japanese Cedar)
Characterized by its clear grain, straight wood texture, unique aroma, and ease of drying. Its uses are diverse, including structural materials, architectural fittings, flooring, paneling, joinery, ceiling panels, packaging materials, and utility poles, making it the most commonly used building material in Japan.
Kiri (Paulownia)
It is said to be the lightest type among domestic woods, characterized by a slightly coarse grain that develops a beautiful luster when polished. In addition to high breathability, it is less affected by humidity and boasts excellent insulation. Its extremely low thermal conductivity and resistance to ignition also lead to its use as inner box material for safes.
Matsu (Pine) / Pine Wood
Processed pine wood is called pine wood. It is characterized by its whitish-yellow hue, and it is known for developing a glossy color change over time due to its high oil content. Also, its softness, characteristic of conifers, makes it popular as a processing material for DIY projects.
Resin
Resin refers to plastic slatted beds.
While its shape is the same as slatted beds made from other natural materials, it is extremely lightweight due to being plastic and boasts excellent durability. Furthermore, it is easy to handle because maintenance is simple. Some products even feature antimicrobial and mold-resistant treatments in the resin itself, allowing for hygienic use.
Types of Slatted Beds
Slatted beds generally come in two types: "stationary" beds that are left in place, and "foldable" beds that can be folded when not in use. Here are the characteristics of each.
Bed Type
- Provides stable support for the body.
- The bed frame is elevated from the floor, allowing moisture to escape easily.
Folding Type
- Allows effective use of small spaces when folded.
- Compact size can reduce moving costs.
- Folding it with the futon helps remove moisture efficiently.
The Key to Slatted Beds Lies in the Bedding Used with Them
Slatted beds, known for their excellent ventilation, are best paired with carefully chosen bedding to enhance comfort, prevent back pain, and reduce creaking noises.
By combining it with a mattress that improves sleep quality, you can achieve even more comfortable sleep.

