How To Install a Freestanding Tub Faucet on Concrete

A freestanding tub faucet can be a beautiful addition to jacuzzi and large centerpiece tubs. But, how do you install it on a concrete slab? 

If you can cut through a concrete slab, you can easily install a freestanding tub faucet on it. However, that may require renting a specialist drill or jackhammer or paying a professional to create the holes for you. Otherwise, there’s little that’s complicated about installing freestanding tub faucets. 

Freestanding Tub Faucet Installation on Concrete Slab 

Installing a freestanding tub faucet on a concrete slab depends on two factors. However, the primary factor is whether or not you can properly install lines. 

Assess Where Pipes Have to Go

Installing pipes under a concrete slab almost always means breaking up the concrete slab. Why? Your concrete slab likely has no space underneath it. While this isn’t always the case, it is true 99 percent or more of the time. Concrete is normally laid onto a packed foundation with no space in between. That’s inconvenient, considering most tub drains require a P-trap and piping underneath the drain. In addition, you’ll have to install the hot and cold-water tubing under the concrete. 

So, you have to decide where the pipes have to go. This means checking the entry point of the copper tubing from the water lines in the house, and plotting the fastest point to the tub faucet. Normally, you should simply draw a straight line across the floor. Then, depending on the accessibility of the slab, you’ll either have to break up the full distance of the slab or use an excavator to tunnel under the slab. The latter option is only an option if you have full access to the outside of the slab. E.g., if you’re installing the tub faucet on an outdoor slab. 

Keeping the Installation in Line with Plumbing Code

Installing plumbing means following plumbing guidelines. In some states, that means hiring a professional. It’s important to check local regulations to see if you can complete installations yourself. However, there are also several plumbing code guidelines to follow if you want to keep your home up to code. That will be important if you ever want to apply for insurance or want to sell the home. 

First, the National Standard Plumbing Code mandates that you cannot cover a hot or cold hot water pipe shutoff valve. Any valves you install into your plumbing must be accessible at all times. So, your best option is to install shutoff valves at the junction with existing pipes. 

You’ll also want to ensure that the P-trap and connections in your tub are under the tub. This is essential to preventing backflow from the sewer and preventing smell. 

Drilling Holes vs Breaking up Concrete

The decision to break up your concrete is a big one. It can weaken your concrete slab if your foundation is not firm enough. It may also not be necessary. If you have access to the outside of the slab and can use a larger pipe to slowly excavate the full length, you’re better off doing that. If you can’t access the outside of the slab at an angle that lines up with the pipe, this is not an option. 

However, this also depends on machine availability. For example, in most cases, it’s easiest to bore holes for pipe if you have an underground or horizontal boring machine. These can be rented for $60-$200 per day from many suppliers. However, they aren’t available everywhere and you might not find one at your local hardware store. 

The alternative is to mark out the length required for the pipe on the top and to use a jackhammer or hammer drill to break up the full line. You can then clean that out, dig into the foundation, and lay the copper pipe that way. 

Both options have pros and cons. 

Getting Professional Advice

In most cases, it’s a very good idea to get a professional assessment of your concrete slab before breaking it up to lay pipe. Of course, if your copper tubing is already in place and was installed before you pour the slab, you can skip this step. If you are planning to break up the slab, you want to be sure that it is absolutely necessary to do so. 

Calling a contractor to request advice or a quote is always a good idea. In most cases, they can also provide the hardware to bore under the slab or the jackhammer to drill through the slab as well. That will save you considerable time and effort over a full DIY job. 

This step is important because breaking up a slab and drilling into it can cause structural weaknesses. If your foundation is weak, it could cause the slab to break. Digging into your foundation might also cause structural weaknesses. For example, storm water could flow into the loosened dirt, which could eventually cause massive structural issues for your home. Always request a professional opinion for taking this kind of step. 

Drilling, Bore, and Break Holes 

Decide how to install the copper tubing for your hot and cold lines, mark out the space, and make the holes. You can then insulate and lay your water lines – either by sliding them under the slab or by laying them from the top of the slab. Make sure the shutoff valves are not under the floor. 

If you haven’t already, you can use this time to install the drainage and the P-Trap, likely in the same holes as you’re using for the water lines. This means that holes should be wide and deep enough to accommodate at least two half inch pipes – although normally you’ll want a 1” or larger pipe for a bathtub drainage system. 

In most cases, you’ll need a concrete drill or hammer drill to get through concrete. If you’re breaking up a line all the way to a wall, you’ll want to rent a jackhammer instead. 

Once you have the pipes in place, you can go ahead and close the holes. Pour new concrete over the holes, with the pipes, including necessary U-bends and flexible pipe at the ends. Some people prefer to use pipe covers or to lay wood over pipes so that they can be excavated more easily if something goes wrong. Most importantly, you want to use stabilizers at the top of the pipe to keep it upright. Use pipe caps and make sure the pipe sticks up well above where you need it, so that it doesn’t accidentally fill with concrete. For example, it’s often a good idea to run the hot and cold-water lines through a PVC pipe. This allows you to pull the copper piping out from either end in case something goes wrong. 

Installing the Faucet 

Most freestanding tub faucets feature a long hollow body, where you can attach water lines to flexible tubing. The faucet then bolts to the floor. You’ll normally need a concrete drill or another heavy duty drill and a suitable drill bit to do this. However, with many different types of freestanding tub fillers available, actual installation may vary. 

It’s always a good idea to wait to fully seal the faucet to the floor until you’ve verified that the connections don’t leak. So, once you’ve connected the pipes, run the water to check the connections. 

Most tub faucets use ½” connectors, so make sure you use ½” copper tubing, rather than the 3/8th inch tubing. If you are using 3/8th tubing, make sure you get converters as well. 

2 Common Problems While Installing Freestanding Tub on Slab 

Installing a freestanding tub on a concrete slab is not easy, unless you’ve laid the concrete after placing the appropriate plumbing. If you’ve done so, it should be relatively easy. 

Breaking Up Concrete 

In some cases, it might not be possible to break up your concrete. That happens if the foundation is too weak. If a contractor advises you not to break up your slab, you should never do it. If you also can’t bore underneath, what can you do? 

Installing Your Tub on a Platform

While it’s not always advisable, it’s always possible to install your freestanding tub on a platform. This allows you to cover the plumbing and water lines with a box – essentially avoiding the problem. However, this might not be recommended, depending on the size of the space and where you want to install the freestanding tub. 

You Can’t Dig Under the Foundation 

If the foundation is too firm or there are rocks under the foundation, you might not be able to dig enough space for the water lines or for the P-Trap. That can prevent you from installing some models of tub.

Choosing the Right Tub 

If your tub requires a sunken drain or a sunken water line, always make sure you pick a model that suits it. Alternatively, you might be able to elevate the tub or get around the issue by using a box for the P-trap. However, this still depends on the tub you pick. 

How to Choose the Right Freestanding Tub Filler

Choosing the right tub faucet is normally a matter of checking the height, size, and pressure requirements for the faucet. A taller faucet can accommodate more tubs. However, it also needs higher water pressure. You also want to look at shutoff valves, connections to water lines, and if the faucet requires some installation in the floor. For example, your faucet may have a mechanism under the floor. This is fine for in a home with a crawlspace or floorspace, but not if you’re installing the faucet in a concrete slab. 

For example, most Delta floor-mount tub fillers use a floor-mount bracket and a ballast, which is intended to go under the floor. This type of installation does not work in most concrete slabs – unless you’re willing to remove and re-pour concrete around it. 

Related Questions 

Installing a freestanding tub faucet on a concrete slab is complicated and likely requires professional assistance. These related questions should help. 

Where is the drain on a freestanding tub? 

Drain placement on a freestanding tub normally depends on the shape of the tub. In an oval tub, the drain is normally at the bottom left. In a round tub, the drain is normally on the bottom. Check your individual model for more specifications. 

Are freestanding tubs hard to get into? 

Freestanding tubs can be quite high. If you have limited mobility, they can be difficult to get into. If so, consider installing a step. You might also want to choose a model with a lowered entry point or built-in steps on the inside. 

Why are freestanding tub fillers so expensive? 

Freestanding tub fillers are expensive for a few reasons. The first is that they are relatively uncommon. That makes them a luxury product which most people will never need or buy. So, the companies manufacturing them have less opportunity to profit off sales and must charge more per model. The second reason is that freestanding tub fillers are quite large compared to wall-mounted counterparts. This can require a considerable amount of chrome – which is expensive. Finally, freestanding tub fillers require good design to maintain water pressure and vacuum from the floor, up the full length of the faucet, and into the tub. 

Final Thoughts

Most people will not want to break up a concrete slab to install water pipes. However, you can’t always bore under your concrete slab to install water pipes the “safe” way. If you’re having trouble, you should always consider contacting a professional and asking for an assessment of the slab and what you can do with the installation. 

In every case, the idea is that you lay pipes and drainage before laying the concrete slab. That allows you to decide on placement, to set everything in, and then to pour a strong concrete slab on top, without risking damage to the foundation or to the slab itself.