The 58.5 x 29 Bathtub Dilemma: Stop Searching, Start Solving

Embarking on a bathroom remodel often starts with an exciting vision. But that excitement can quickly turn to frustration when you discover your bathtub alcove has non-standard dimensions, like 58.5 x 29 inches. This discovery leads to a frantic search for a replacement, only to find that most standard tubs won’t fit.

This situation is surprisingly common, especially in older homes where construction standards were different. The core of the problem isn’t just about finding a smaller tub; it’s about finding a solution that is durable, waterproof, and aesthetically pleasing without requiring a full-scale, wall-altering renovation.

Why Finding a 58.5 x 29 Bathtub Is So Difficult

The primary challenge is that modern manufacturing is built around standardization. Most alcove bathtubs are produced to fit a 60-inch wide space, which is the standard stud-to-stud measurement in modern construction. A measurement of 58.5 inches often indicates that layers of drywall, backer board, and tile have reduced the original 60-inch opening.

This leaves homeowners in a difficult position, caught between the mass market’s offerings and their home’s unique requirements. The search for a “bathtub 58.5 x 29” can feel like a search for something that doesn’t exist, leading to stress and project delays.

The Myth of “Standard” Bathtub Sizes

While 60 inches is the most common length for an alcove tub, it’s far from the only size. However, sizes under 60 inches are less common and often cater to specific needs, such as mobile homes or very compact bathrooms. The 58.5-inch dimension falls into a gray area—it’s not a standard size, but it’s a common problem.

This dimensional quirk is a remnant of past building practices. Older homes were often built with less precise measurements, and materials like thick plaster and lathe walls could easily reduce an alcove’s finished dimensions.

Older Homes and Their Unique Dimensions

If you live in a house built before the widespread adoption of standardized framing, you’re more likely to encounter these unique measurements. What was once a standard 60-inch rough opening can shrink significantly after decades of updates and layers of new wall coverings.

Before you begin any demolition, it’s vital to understand your home’s unique structure. Understanding the full picture of your home’s systems, like knowing where your floor vents lead to, is a critical step in planning a successful renovation. This knowledge helps prevent surprises and ensures you’re making informed decisions.

Before You Buy: The Ultimate Measurement Checklist

Accurate measurements are the foundation of a successful bathtub installation. A simple tape measure reading from tile to tile is not enough. You must measure the stud-to-stud distance to understand the true size of your alcove.

To do this, you may need to remove a small section of drywall or tile. This step, while seemingly destructive, can save you from purchasing a tub that simply will not fit. It is the most critical measurement you will take.

Measuring More Than Just Length and Width

Beyond the length, consider the depth and height. The width of 29 inches is also slightly non-standard, as 30 or 32 inches are more common. Ensure your chosen replacement will not only fit the length but also the width, without obstructing nearby fixtures like a toilet.

Also, measure the soaking depth from the tub floor to the overflow drain. This is a crucial factor for comfort, especially if you enjoy deep, relaxing baths. A taller tub might offer a better soaking experience without requiring more floor space.

Checking for Plumb Walls and Square Corners

Older homes are rarely perfect. Walls can bow, and corners are often not a perfect 90 degrees. Use a level to check if your alcove walls are plumb (perfectly vertical).

An out-of-plumb wall can create significant installation challenges and lead to gaps. Knowing this in advance allows you to plan for corrective measures, such as shimming the studs to create a true, square installation surface for your new tub.

Top 3 Solutions for Your 58.5 x 29 Inch Alcove

Faced with a non-standard alcove, you have three primary paths forward. Each offers a distinct balance of cost, effort, and outcome. Carefully consider each option to determine the best fit for your budget and long-term goals.

Solution 1: The “Close-Enough” Fit with a Filler Strip

One common approach is to purchase a slightly smaller tub, such as a 54-inch model, and fill the remaining gap. This gap can be covered with a custom-built ledge, tiled shelf, or a waterproof filler strip. This solution avoids major wall modifications.

While practical, the key to success is expert waterproofing. Any gaps, no matter how small, must be perfectly sealed to prevent water from seeping into the wall cavity, which could lead to mold and structural damage over time.

Solution 2: Bathtub Refinishing and Reglazing

If your existing bathtub is structurally sound but cosmetically flawed with stains or minor scratches, reglazing is an excellent option. This process involves professionally applying a new, durable finish to the tub’s surface, making it look brand new.

Bathtub refinishing is significantly more affordable and less disruptive than a full replacement. The entire process can often be completed in a single day, offering a quick and effective upgrade without the hassle of demolition.

Solution 3: The Custom Bathtub Option

For those who want a perfect fit without compromise, ordering a custom-sized bathtub is the ultimate solution. Several manufacturers offer bespoke services, allowing you to specify the exact dimensions required for your unique space.

While this is the most expensive option, it guarantees a seamless fit and eliminates the need for fillers or modifications. A custom tub provides a high-end, integrated look that can elevate the entire bathroom.

Comparing Your Options: A Head-to-Head Breakdown

Choosing the right path requires weighing the pros and cons of each solution. The best choice depends on your budget, timeline, and the condition of your current bathtub.

Solution	Pros	Cons	Best For
Filler Strip with Smaller Tub	Avoids wall demolition; relatively low cost.	Requires meticulous waterproofing; may look like a patch.	Budget-conscious renovations where preserving walls is a priority.
Bathtub Refinishing/Reglazing	Highly cost-effective; fast turnaround; no demolition.	Only suitable for tubs with cosmetic damage, not structural issues.	Structurally sound tubs that just need a cosmetic facelift.
Custom-Sized Bathtub	Perfect, seamless fit; high-end look; no compromises.	Highest cost; longer lead times for manufacturing.	High-end renovations where budget is less of a concern than a perfect fit.

Installation Secrets for Non-Standard Bathtubs

Installing a tub in a tight or uneven space requires precision. A solid, level base is non-negotiable. Most installers recommend setting the tub in a mortar bed to provide a rock-solid foundation and prevent any flexing or creaking.

This is especially critical for acrylic or fiberglass tubs, which can feel less rigid than their cast iron counterparts. A proper mortar base ensures the tub feels sturdy and will last for decades without developing stress cracks.

Prepping the Alcove for a Secure Fit

Before the tub goes in, ensure the alcove is ready. The studs should be clean, and a ledger board should be installed along the long wall to support the tub’s flange. This board must be perfectly level to ensure the tub drains correctly.

Taking the time for proper prep work is a hallmark of professional installation. Much like how a skilled technician would test a C-wire with a multimeter before installing a smart thermostat, a good plumber will ensure the foundation is perfect before setting the tub.

Dealing with Gaps and Ensuring a Watertight Seal

Even with careful planning, small gaps may appear between the tub and the wall. For gaps smaller than 1/4 inch, a high-quality, 100% silicone caulk will provide a flexible, waterproof seal. Fill the tub with water before caulking to weigh it down to its lowest point, which prevents the caulk from splitting later.

For larger gaps, a foam backer rod should be inserted before caulking. This provides a solid base for the caulk and ensures a durable, long-lasting seal. Never simply fill a large gap with caulk alone, as it will sag and fail over time.

Choosing the Right Bathtub Material

The material of your bathtub affects its durability, heat retention, and maintenance requirements. Each has its own set of advantages that cater to different preferences and budgets.

Acrylic: The Versatile and Popular Choice

Acrylic tubs are a popular choice due to their versatility and affordability. They are lightweight, making them easier to install, and the material is warm to the touch. The non-porous surface is also resistant to staining and easy to clean.

Modern acrylics are reinforced with fiberglass, making them quite strong and durable. They are available in the widest range of shapes and sizes, increasing the likelihood of finding a model that works for a non-standard space.

Cast Iron: The Classic, Durable Heavyweight

Cast iron tubs are known for their incredible durability and excellent heat retention. The thick enamel coating is highly resistant to scratches and chemicals. With proper care, a cast iron tub can last a lifetime.

However, they are extremely heavy, which can complicate installation, especially on upper floors. The weight may require additional reinforcement of the subfloor, adding to the overall project cost. Proper home maintenance, much like knowing the location of a fuel shut-off valve on your equipment, involves understanding and preparing for these structural demands.

Fiberglass: The Budget-Friendly Option

Fiberglass (or FRP) tubs are the most affordable option on the market. They are very lightweight and easy to install, making them a favorite for DIY projects. The gelcoat finish provides a glossy, easy-to-clean surface.

The main drawback of fiberglass is its relative lack of durability. The surface can be prone to scratching and fading over time, and the material can feel more flexible than acrylic or cast iron.

Frequently Asked Questions (FAQ)

Is a 58.5-inch bathtub alcove a serious problem?
It is not a serious problem, but it does require careful planning. It simply means standard 60-inch tubs will not fit without modification, so you must choose one of the alternative solutions discussed, such as reglazing, using a smaller tub with filler, or ordering a custom unit.

Can I cut a small amount off the end of an acrylic tub to make it fit?
This is strongly discouraged. Cutting a bathtub will void its warranty and can compromise its structural integrity and waterproof flange. This could lead to leaks and significant water damage down the line.

How much does it cost to reglaze a bathtub?
Professional bathtub reglazing is a cost-effective solution, typically ranging from $400 to $700. This is significantly less than the cost of a full replacement, which can run into the thousands when factoring in labor, plumbing, and tile work.

Conclusion

stress-free renovation requires shifting focus from a frantic search for a standard-sized tub to embracing custom, flexible, or alternative solutions. While conventional $60$-inch tubs are off the table, the best path forward involves:

1. Exploring Niche Products: Investigating specialized $54$– or $58$-inch models, often available from smaller manufacturers.

2. Considering Alternative Fixtures: Substituting the tub for a custom shower pan and glass enclosure, which offers full waterproofing and a modern aesthetic without altering the wall structure.

3. Utilizing Strategic Materials: Employing the remaining gap (e.g., the $1.5$ inches for a $57$-inch tub) to create a tiled niche or shelf, turning a problem into a high-value feature.