"Can You Cut Floor Joists for a Curbless Shower? Expert Guide"

Embracing the trend of curbless showers in your home renovation project? Before you start, you might be wondering, "Can you cut floor joists for a curbless show...

Can You Cut Floor Joists for a Curbless Shower? A Comprehensive Guide

Curbless Shower: Benefits & Drawbacks
Curbless Shower: Benefits & Drawbacks

Embracing the trend of curbless showers in your home renovation project? Before you start, you might be wondering, "Can you cut floor joists for a curbless shower?" The short answer is yes, but it's not as simple as grabbing a saw and making a few cuts. This guide will walk you through the process, ensuring you understand the implications and steps involved in modifying your floor joists for a curbless shower.

BUILDING a CURBLESS SHOWER (Recess in Floor Joists)
BUILDING a CURBLESS SHOWER (Recess in Floor Joists)

Understanding Curbless Showers and Floor Joists

Curbless showers, also known as barrier-free showers, are designed to be wheelchair accessible and aesthetically pleasing. They create a seamless look by eliminating the traditional shower curb or lip. Floor joists, on the other hand, are the horizontal framing members used in floor construction to span an open space and provide support for the floor above.

Cutting Down Floor Joists for Curbless Entry Shower in Upstairs Bathroom
Cutting Down Floor Joists for Curbless Entry Shower in Upstairs Bathroom

When installing a curbless shower, the shower base needs to be sloped towards the drain, which typically requires cutting into the subfloor and sometimes the floor joists. This allows for proper water drainage and prevents water from pooling in the shower.

Factors to Consider Before Cutting Floor Joists

How to Install a Shower Pan (Leak-Proof Guide)
How to Install a Shower Pan (Leak-Proof Guide)

Structural Integrity

  • Floor joists bear the weight of the floor and anything on it. Cutting into them can compromise their structural integrity if not done correctly. Always ensure you understand the load-bearing capacity of your joists and the impact of your cuts.

  • Consult with a structural engineer if you're unsure about the structural implications of your cuts. They can provide guidance tailored to your specific situation.

    • How to Build a Curbless Shower: Must-Have Detail | DIYTileGuy
    How to Build a Curbless Shower: Must-Have Detail | DIYTileGuy

    Joist Size and Spacing

    • The size and spacing of your joists will determine how much you can safely cut. Standard joist sizes range from 2x8 to 2x12, with 16" to 24" on center spacing. Larger joists and closer spacing provide more support and allow for more cutting.

    30 second curbless shower #shorts #shortsvideo #diy #tile
    30 second curbless shower #shorts #shortsvideo #diy #tile

  • As a general rule, you should not cut more than 25% of the depth of a joist. This ensures the joist can still bear its load safely.

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    108K views · 1.4K reactions | Curbless Shower BUILD Highlights | Why step over a curb if you don't have to ? 😄 ❤ I love curbless showers ❤ Hydro-Blok has made barrier-free showers easy to BUILD 👊 Here's a list of all... | By Bathroom Remodeling Teacher | Alright, so let me give you the highlights of the construction of a curbless shower. Lot of people are confused about this and I can understand why, I mean, when you see the finished product, all you see is a nice flush surface into the shower and it doesn't make a whole lot of sense how that was done. Majority of the systems out there including the hydro block system is created so that you can recess the plywood within the shower area. So, you can see my existing floor joist here and here. I have the plywood built in between it. So, it's at at the same level as a joist. So this is where it's nice not having the riser pipe glued. Just take it out. Put your plywood down and then cut out where that needs to be. Now, when you put new subflooring or if you have existing subflooring, most of the time you're three quarters of an inch. I So, you have a three-quarter-inch drop down into the shower and the shower pans are made an inch thick. So, this one's set in the place. You basically have a quarter-inch difference in height between the outside floor and the inside and there's a bunch of different ways you can go about addressing that. One, which is the one that we're going to be doing in this particular bathroom is to use an uncoupling membrane. This is a quarter-inch uncoupling membrane made by Hydro Block. It's waterproof and it makes a nice seamless entrance into the shower. So, this is going to build it up the outside floor that quarter inch. The uncoupling membrane is also used to separate the plywood layer from the tile layer and you know, preventing cracks and you know, basically, it's a crack isolation membrane. So, this is a great way to go about it. Another alternative is to use their quarter-inch foam board. So, this is one-quarter-inch thick. You can thin set this down and screw it into place and that would also make a nice transition into the shower. Now, one reason that you really might want to go with this is that if you're doing some small mosaic tiles. If you're doing penny tiles, if you're doing something less than two inch by two-inch tiles, this would be a great way to go because it's a nice, smooth surface that's going to be easy to tile over. So, this is a great way this would be also be 100% waterproof on the outside floor and the third way would be to simply floor level the entire outside floor area and just floor level up to the shower pan in some ways that could be the most foolproof way if you had an unlevel floor on the outside floor or if you had a little bit more of a raise on the pan from one side or the other you can make everything perfectly transitioned so just adding floor level now the one thing you would want to do on top of the floor leveler is to actually do a liquid water proofing so that you have everything 100% waterproof. That's the one big difference between a tiled shower and a curveless shower is waterproofing. You really want to have at the very minimum three feet of waterproofing outside of the shower but I would really highly recommend you just do the entire bathroom floor so you have it. Don't have any issues with water migration through the thin set layer and getting out into that plywood layer.
    108K views · 1.4K reactions | Curbless Shower BUILD Highlights | Why step over a curb if you don't have to ? 😄 ❤ I love curbless showers ❤ Hydro-Blok has made barrier-free showers easy to BUILD 👊 Here's a list of all... | By Bathroom Remodeling Teacher | Alright, so let me give you the highlights of the construction of a curbless shower. Lot of people are confused about this and I can understand why, I mean, when you see the finished product, all you see is a nice flush surface into the shower and it doesn't make a whole lot of sense how that was done. Majority of the systems out there including the hydro block system is created so that you can recess the plywood within the shower area. So, you can see my existing floor joist here and here. I have the plywood built in between it. So, it's at at the same level as a joist. So this is where it's nice not having the riser pipe glued. Just take it out. Put your plywood down and then cut out where that needs to be. Now, when you put new subflooring or if you have existing subflooring, most of the time you're three quarters of an inch. I So, you have a three-quarter-inch drop down into the shower and the shower pans are made an inch thick. So, this one's set in the place. You basically have a quarter-inch difference in height between the outside floor and the inside and there's a bunch of different ways you can go about addressing that. One, which is the one that we're going to be doing in this particular bathroom is to use an uncoupling membrane. This is a quarter-inch uncoupling membrane made by Hydro Block. It's waterproof and it makes a nice seamless entrance into the shower. So, this is going to build it up the outside floor that quarter inch. The uncoupling membrane is also used to separate the plywood layer from the tile layer and you know, preventing cracks and you know, basically, it's a crack isolation membrane. So, this is a great way to go about it. Another alternative is to use their quarter-inch foam board. So, this is one-quarter-inch thick. You can thin set this down and screw it into place and that would also make a nice transition into the shower. Now, one reason that you really might want to go with this is that if you're doing some small mosaic tiles. If you're doing penny tiles, if you're doing something less than two inch by two-inch tiles, this would be a great way to go because it's a nice, smooth surface that's going to be easy to tile over. So, this is a great way this would be also be 100% waterproof on the outside floor and the third way would be to simply floor level the entire outside floor area and just floor level up to the shower pan in some ways that could be the most foolproof way if you had an unlevel floor on the outside floor or if you had a little bit more of a raise on the pan from one side or the other you can make everything perfectly transitioned so just adding floor level now the one thing you would want to do on top of the floor leveler is to actually do a liquid water proofing so that you have everything 100% waterproof. That's the one big difference between a tiled shower and a curveless shower is waterproofing. You really want to have at the very minimum three feet of waterproofing outside of the shower but I would really highly recommend you just do the entire bathroom floor so you have it. Don't have any issues with water migration through the thin set layer and getting out into that plywood layer.
    5 Reasons to use a One Level Wet Room Shower vs. a Shower Base with a Curb
    5 Reasons to use a One Level Wet Room Shower vs. a Shower Base with a Curb

    Steps to Cut Floor Joists for a Curbless Shower

    If you've determined that cutting your floor joists is safe and necessary, follow these steps:

    1. Locate the joists using a stud finder. Mark their position on the ceiling below and the floor above.

  • Determine the exact cuts you need to make. Use a shower base template or draw the shower base shape on the floor to ensure accurate cuts.

  • Use a reciprocating saw or a jigsaw with a fine-tooth blade to make your cuts. Start from the bottom of the joist and cut upwards to avoid splintering. Make sure to wear safety glasses and other appropriate safety gear.

  • After cutting, install sister joists or additional support to reinforce the structure. Sister joists are new joists installed alongside the existing ones, providing additional support and helping to distribute the load.

  • Install the shower base and ensure it's properly sloped towards the drain. This is crucial to prevent water from leaking into the subfloor or causing other damage.

    • Alternatives to Cutting Floor Joists

    If cutting your floor joists isn't feasible or safe, consider these alternatives:

    • Install a shower pan with a curb. This is a traditional shower base that requires a curb to contain the water. It's a simpler and safer option if you can't cut your joists.

  • Use a shower base with a sloped pan that fits within the existing joist structure. These bases are designed to fit within standard joist spacing and don't require cutting into the joists.

    • Conclusion

    Can you cut floor joists for a curbless shower? Yes, but it's a task that requires careful planning, understanding of your home's structure, and often professional guidance. Always prioritize safety and structural integrity when modifying your home. If you're unsure about any aspect of the process, consult a professional before proceeding.

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