HOMEWORK/Installing a vintage bathtub
The good news
There are no extraordinary plumbing requirements for the tub. The biggest things you have to consider are the rough-in locations for the exposed drain piping and the decorative water supply lines. These need to be precisely positioned so they are plumb and centered with the tub. A good plumber can do this with little effort.
The bad news
A bigger concern is the subfloor framing. A vintage tub produces concentrated loads at the four spots where the feet touch the floor. A standard built-in tub that's properly supported usually transfers its weight to the side wall and along the entire edge of the tub skirt. Some built-in tubs have a rigid foam pad under them that helps distribute the load.
A solution
Install vertical blocking directly under the location of each foot of the vintage tub you're installing. This blocking consists of a short piece of floor joist that's nailed between two other full-length floor joists. This blocking prevents the subfloor sheathing from sagging under the weight of the loaded tub.
Keep in mind
Water can splash out of these tubs if kids are in them or if you have a one with a built-in whirlpool feature. Many think that a tile floor is waterproof. Most tile is waterproof, but the grout lines between the tiles are not. Water can seep through a grout joint and over time cause wood rot under a tub.
Waterproofing
You can treat regular wood with a borate solution that is safe for humans but toxic to most fungi that cause wood rot. Spray the floor joists several times with this solution, as well as to saturate the subfloor sheathing on both the top and underside. When the borate solution dries, it does a great job of protecting regular lumber. You can also install 30-pound felt paper on top of the subfloor before the cement-based tile underlayment is installed. Overlap the felt seams no less than 9 inches. This felt can extend over the entire subfloor of the bathroom and turn up several inches where it touches the walls.
The right lines
Be sure the water supply lines that feed the tub faucet are at least three-quarters of an inch in diameter. Vintage tub faucets often are designed to allow for a heavy flow of water so the tub fills quickly. If you have half-inch supply lines and normal water pressure, the tub can take time to fill.
Exhaust fans
Remote exhaust fans are very quiet and will allow you to vegetate in the tub without the pesky drone of a standard exhaust fan. Remote fans gently vacuum all of the water vapor produced by the steaming bath out of the room and through the roof of your home. Place the fan inlet over the tub. Many come with an accessory light to illuminate the tub. You can connect two inlets to the same fan, allowing you to fully ventilate the bathroom.
- Tribune Media Services
