Japanese Ofuro Soaking Tub FAQs

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Q.  What sizes are available?

A.  If you can imagine it, we can make it (almost). We have no “standard” sizes and most every Ofuro we have made over the last 20 years has been customized to the needs and desires of the client in one way or another. We’ve made them as large as 7′ x 5′ x 4′ deep , and as small as 2′ x 2′ x 2′. Although we have made them as long as 7′, currently the largest Ofuro we’ll make is 5′ x 5′ or 6′ x 4′.

This is due to a decrease in stability as the size increases. The “typical” depth is 26″ to 28″ where upon you sit on the floor. It’s not uncommon though, to make them deeper, up to 48″, and have a bench for seating.

As the size of the Ofuro increases, the thickness of the walls increase as well. Up to 28″ deep the walls are 2″ thick. Over 28″, up to 36″ a thickness of 3″ is required and over 36″ the thickness increases to 4″. If forced to give a “typical” size, 3′ x 5′ x 28″ deep is somewhat common.

Q. How is the size specified?

A.  Due to our unique manufacturing process, it’s important to understand how the “specified size” relates to the actual finished size. Length and width refers to the overall outside dimensions, meaning the inside length and width will be smaller due to the thickness of the sides.

The thickness of sides range from 2″ to 4″ thick, depending on the overall depth of the Ofuro (up to 28″ deep, 2″ thick sides, over 28″ to 36″ deep – 3″ thick. Over 36″ deep, 4″ thick). The height refers to the actual inside depth, meaning the overall height will be higher due to the thickness of the floor and the added height from the small joists the Ofuro sits on.

With our optional slopped backs, length and width measurements are determined at the top of the Ofuro. The slopes are at a fixed 15 degrees (this angle can not be changed) and the bottom dimensions fall where they may.

Q.  How do they drain and overflow?

A.  In order to obtain maximum water depth for the most enjoyable soaking, Ofuros don’t have an overflow like the typical American bathtub. While we have on occasion installed “conventional” overflows, the preferred style allows the Ofuro to simply overflow over the top. This of course requires that the Ofuro be installed on waterproofed floor with a center drain.

For draining there’s a few options. If the Ofuro is being filled and drained for each use, included is a custom, 1″ MPT, flush mounted, bronze drain fitting. The location of the drain can be specified to exactly match your plumbing layout, and it includes a lever operated stopper. An optional fully electronic drain valve is also available.

Ofuros with a recirculating heating system or that are fully jetted, can have the above configuration as an option, but more frequently the draining is done through the plumbing. A “T” with a valve is simply installed into the added plumbing.

Q.  What different woods can an Ofuro be made of?

A.  The vast majority of Ofuros are made either of hinoki or teak. Other woods that have been used are yellow cedar, western red cedar, Spanish cedar and others. While hinoki is more traditionally Japanese, teak is slightly more durable and less prone to staining. Due to the majority of the production costs being labor, the type of wood you choose has little or no effect the overall cost of the Ofuro.

Q.  Can they be located outdoors?

A.  Yes, however there are some special considerations. If located outdoors the Ofuro has to be completely shaded from direct sunlight. We also don’t advise anything larger than 5′ x 3′ going outside, and teak is without a doubt, the preferred wood of choice.

Q.  Can I use soap in an Ofuro?

A.  No. The Ofuro is intended specifically for soaking and soap will cause permanent staining to the wood.

Q.  How is the wood treated?

Our Ofuros are made of all wood with no finish applied to them. We do not recommend any type of finish, nor can we even suggest one.

Q.  How are Ofuros heated?

A.  Most residential home do not have enough hot water supply to fill an Ofuro. With every cubic foot of water being 7 gallons, smaller Ofuros hold about 100 gallons and a “typical” 5′ x 3′ x 26″ deep Ofuro holds about 160 gallons.

Some instantaneous water heaters can fill an Ofuro, but most people chose to add a small recirculation (pump) system with an electric “spa” heater. Adding a filter and ionizer to this, one can reuse the water for up to a week without the use of standard hot tub chemicals. Using a small amount of chemicals the water can last up to 3 months.

Q.  Can they be outfitted with jets?

A.  Absolutely! Just like a normal hot tub or spa an Ofuro can be jetted. Just like the drain fittings, the jets are a custom clear coated solid bronze fitting.  The location of the jets needs to be determined before construction of the Ofuro is completed as they must be installed during the construction process.

Also, keep in mind that jets require plumbing on the exterior of the Ofuro. It will almost certainly be preferred to cover/hide this plumbing with some type of deck or surround, build on site.

Q.  How much does an Ofuro weigh when filled?

A.  The weight of a filled Ofuro is determined by simply calculating its size in cubic feet, and multiplying by 65 (equals total pounds weight). Since most Ofuros are sized by inches (outside length x outside width x overall outside height), it can be easier to determine the weigh based upon cubic inches. Total cubic inches, divided by 26.5, will result in the overall weight went filled in pounds.