By Vasile Teterea, Owner and CEO, Firm Remodeling LLC. Washington Contractor License #FIRMRRL783PU. Serving Kent, Maple Valley, Covington, Renton, Black Diamond, Ravensdale, Hobart, Issaquah, Enumclaw, Auburn, and Federal Way, WA. Published August 2, 2026.
A curbless shower is the most requested thing in our bathroom work right now, and it is also the one request I have to walk back the most often. Not because it looks bad or costs too much. Because of what is under the floor.
Here is the short version. A curbless shower needs the tile inside the shower to sit lower than the tile outside it, or water leaves the room. Getting that drop almost always means cutting into the subfloor and reworking the floor framing. Whether that is a two hour job or an impossible one depends entirely on what kind of joists your house was built with, and in Kent that comes down to roughly what year the house went up.
If you want the answer for your own house before you read another word: go look at the ceiling under your bathroom, or crawl under it, and tell me whether you see solid wood boards or something that looks like it was manufactured. That one detail decides most of it.
Why a curbless shower needs a hole in your floor
A shower floor has to slope toward the drain at about a quarter inch per foot. On a 60 inch shower with a center drain, that is roughly three quarters of an inch of fall from the walls to the middle. Stack the waterproofing membrane, the mortar bed, thinset, and tile on top of that, and you need somewhere between one and a half and two and a half inches of total build-up.
With a curb, none of that matters. You build up on top of the existing subfloor and the curb holds the water in.
Curbless, you have two choices. Drop the shower area down into the floor framing, or raise the entire rest of the bathroom up to match. That is the whole problem in one sentence. Most people assume it is a design decision. It is a framing decision, and the framing was decided before you bought the house.
The four floors we find in Kent, and what each one means
Kent housing stock is not one thing. East Hill alone spans four decades of building practice, and the framing changed underneath all of it.
Solid sawn joists, roughly 1965 to 1992
This is most of what we see in older East Hill, West Hill, Scenic Hill, and the Mill Creek area. Real 2x8s or 2x10s cut from a tree, usually 16 inches on center.
This is the good case. We are not notching anything. We cut out the subfloor in the shower footprint, fasten ledger strips to the sides of the joists an inch and a half or two inches below the top, and drop a new panel of plywood into that recess. The joists keep their full depth and full strength. Nobody weakens anything.
The two things that can still stop us: a 2×6 joist, which is too shallow to give up two inches of anything, and a heating duct or a drain line already running through the bay we need. We find one or the other maybe one job in six.
I-joists, roughly 1993 through the mid 2000s
Lake Meridian, parts of Panther Lake, a lot of the early nineties plats. These look like a capital I from the side. A thin plywood web with a narrow wood flange top and bottom.
You cannot cut the flanges. Ever. All of the strength lives in those two strips, and the manufacturer’s own literature is clear that removing any part of a flange voids the rating on the member. Nobody is signing off on that, and I would not do it if they did.
Sometimes we can still get there. If the shower lands so the drain and the recess fall inside the web area, and the manufacturer’s hole chart allows a penetration in that spot, we have room to work. If the recess would land on a flange, the answer is no, and no amount of paying me more changes it.
Open web floor trusses, roughly 2003 onward
Newer Panther Lake infill, newer builds along the Covington line. These are the ones that look like a bridge, wood chords top and bottom with diagonal webbing in between.
Homeowners assume these are the worst case. They are usually the easiest. The open spaces between the webs let us run a drain almost anywhere without touching structure, and the trusses are typically deep enough that a shallow recess costs nothing. What you cannot do is cut a web member. The truss is engineered as a system, and one cut chord changes the load path for the whole span.
Concrete slab
Older ramblers south of downtown, and basement bathrooms in daylight homes across the East Hill.
Different problem, same answer. There is no framing bay to drop into, so getting a recess means saw cutting and breaking out concrete, then re-pouring around the new drain. It is doable. It is loud, dusty, and adds real money and about three days. We usually talk people out of it unless accessibility is the actual reason for the project.
Four things you can check yourself tonight
Before you call me or anyone else, you can narrow this down in about ten minutes.
Look at the ceiling directly below the bathroom. If it is a finished ceiling, look in the crawlspace or the unfinished part of the basement instead and follow the framing toward the bathroom. Solid boards mean you are probably fine. Anything that looks factory made means we need to check the manufacturer’s specs.
Find out which direction the joists run. Stand in the bathroom doorway. If the joists run the same direction as the doorway wall, we may only have one or two bays to work in. Crossways gives us more room and more options.
Check whether the bathroom shares a wall with the garage or sits over one. Kent homes with bathrooms over a garage almost always have a longer span there, and long spans mean the engineer gets involved.
Measure the gap under your bathroom door. If there is an inch or more of clearance, raising the whole bathroom floor becomes a real option instead of a last resort. Under half an inch and you would be cutting doors and resetting casings.
None of this is a substitute for pulling up a piece of subfloor and looking, which is what we do at the estimate. But it tells you whether to get your hopes up.
When the answer is genuinely no
I would rather tell somebody no at the estimate than find out in week three. The situations where we say no outright:
The bathroom sits over a flange we cannot cut, and moving the shower to a different wall does not work for the layout.
The bathroom is on the second floor over a finished ceiling the homeowner does not want opened. We can technically do it. We just have to open your dining room ceiling to do it, and most people would rather have a low curb.
The joists are already sagging, cut up by a previous plumber, or showing rot at the ends. Then we are having a repair conversation first, not a shower conversation. We run into this more often than you would think in homes where a shower leaked quietly for a decade.
The house is on a slab and the budget is a normal shower budget.
What we build instead, and honestly nobody notices
Every one of these has made a client happy after they were told no on true curbless.
A low curb at two inches instead of the usual four to five, with the top beveled and the tile carried over it. You still step, but barely, and a walker clears it. This is what we build most often as the fallback.
A linear drain against the back wall. Sloping in one direction instead of four cuts the depth we need roughly in half, which sometimes turns a no into a yes on a floor that was one inch short. It costs more than a center drain and it is usually worth it.
Raising the bathroom floor. We build up the area outside the shower with plywood and self leveler and use a small ramp at the doorway. This works well in a bathroom with a generous door gap. It does mean cutting the door, resetting the toilet flange, and dealing with the transition to the hallway.
Moving the shower a few feet to land it in a workable bay. Not always possible. Worth asking about before you give up on the idea.
If your project started as a tub swap rather than a full gut, our tub-to-shower conversions guide covers where those two paths separate.
What this costs in Kent
Our shower-only remodels in Kent generally land between $8,000 and $18,000. Going curbless changes that in specific, predictable ways:
Recessing the framing in a solid sawn floor adds roughly $900 to $2,200 depending on how many bays we open and whether we have to reroute a duct.
A linear drain instead of a center drain adds about $350 to $700 for the drain assembly and the extra layout time.
Raising the whole bathroom floor instead adds roughly $1,800 to $3,500 once you count the subfloor, the door work, the flange extension, and the trim.
Cutting a slab adds $2,500 to $4,500 and about three days.
An engineer’s letter, when we need one, runs $500 to $1,200 in this market.
Most finished curbless showers we build in Kent land between $14,000 and $26,000. If you want to see how bathroom pricing here compares to the surrounding cities, we broke that down in our Renton vs. Kent vs. Bellevue master bath cost post.
Permits, and the part contractors skip
Modifying floor framing is structural work. The City of Kent is direct about this: a permit is required for work that changes a building’s structure, and their Do I Need a Permit page lists tiling and similar finish work as exempt while structural alteration is not. Recessing a floor is not tiling.
We pull the permit in your name, we schedule the framing and rough plumbing inspections, and the inspector looks at the recess before anything gets covered. If a contractor tells you a curbless shower does not need a permit in Kent, that means they are planning to drop the floor without anyone checking their work. Ask them directly.
There is more on how Kent permitting actually runs in our post on permits, plumbing, and planning for Kent homeowners.
The framing is only half of it
A curbless shower has no curb to catch a waterproofing mistake. The recess is the part that decides whether you can have one. The waterproofing is the part that decides whether it is still dry in five years, and it is where most of the failures we get called to fix actually started. We wrote up our full pan and membrane process in how we waterproof a curbless walk-in shower, and I would read that one before you hire anybody, including us.
Two other things worth thinking about at the same time, because the floor is already open: the drain layout locks in your tile pattern, which we get into in our bathroom tile guide for Kent, and if you have ever wanted heated floors, this is the only cheap moment to add them.
Frequently asked questions
Can any bathroom be made curbless?
No. Roughly one Kent bathroom in five that we look at cannot take a true curbless shower without work the homeowner would not want to pay for. Usually the reason is I-joists, a slab, or a second floor bathroom over a finished ceiling.
Do I need an engineer?
Not for a standard recess in solid sawn joists. You do if we are modifying an I-joist or a truss, if the span is long, or if the bathroom sits over a garage. Kent will ask for the letter at plan review when it applies.
Will a curbless shower leak more than a regular one?
Not if it is built right. It is less forgiving of a bad build, because there is no curb holding water back. Every curbless failure I have been called to repair traced back to waterproofing or slope, not to the missing curb.
Does a curbless shower add value in Kent?
For most buyers it reads as a current, well kept bathroom, which helps. It matters more if you plan to stay in the house. If you are remodeling specifically to sell, keep at least one tub somewhere in the house.
Do you have to remove the whole bathroom floor?
No. We open the shower footprint plus about a foot past it. The rest of the floor stays.
How much longer does curbless take?
Two to four extra days on a shower-only project, mostly framing, inspection scheduling, and letting the mortar bed cure properly.
Come look at the floor with us
If you are somewhere in Kent thinking about a curbless shower, the honest next step is to have somebody pull up a piece of subfloor and look. We do that at the free in-home estimate, and we will tell you at that appointment whether the answer is yes, no, or a low curb.
You can see finished examples on our projects page, or read more about bathroom remodeling in Kent.
Firm Remodeling LLC 26424 233rd Ave SE, Maple Valley, WA 98038 (206) 773-8264 WA Contractor License #FIRMRRL783PU. Licensed, bonded, and insured.
We do this work throughout Kent, Maple Valley, Covington, Black Diamond, Hobart, Renton, and Issaquah, plus Ravensdale, Enumclaw, Auburn, and Federal Way. Request a free estimate or call (206) 773-8264.
