Diamond Bar: Two Bathrooms and a Powder Room

Three rooms in one Diamond Bar house, done together: two full bathrooms and a powder room. Different tile, different hardware, different size — but one crew, one schedule and one set of decisions, which is the only sensible way to do three wet rooms in the same property.

Walk-in shower in grey stone-look tile

Project at a glance

Location	Diamond Bar, CA
Completed	2026
Project type	Two bathroom remodels and a powder room
Scope	Demolition, waterproofing, large-format tile, linear drains, frameless and sliding glass enclosures, vanities, wall-hung and standard fixtures, lighting and finishes across three rooms

Doing three rooms at once

Homeowners often stage bathrooms one at a time to spread the disruption. It is a reasonable instinct and it usually costs more. Demolition, waterproofing, tiling and glass all come back to site three separate times, and the household lives through it three separate times.

Done together, each trade comes once. The trade-off is that you are without more of the house at the same time, so it only works if there is a bathroom left to use — which is exactly the sort of thing to work out at the site visit.

Large-format tile and linear drains

Two of these rooms use large-format marble-look porcelain, which looks simple and is not. Big tiles show every deviation in the substrate, so the floor has to be flattened properly before anything is set, and the layout has to be planned so the cuts land where they are least visible.

The linear drain in the third photograph is part of the same thinking: a single fall in one direction instead of four falls into a centre point, so a large tile can run straight through the shower without being cut into wedges. It costs more and it is the difference between a floor that looks intentional and one that looks fought with.

The three rooms

Compact bathroom with a wood-effect vanity, wall-hung toilet and large-format marble floor tile in Diamond Bar — Wood-effect vanity against large-format marble

Frameless glass shower enclosure opening onto marble floor tile in a Diamond Bar bathroom — Wood-effect vanity against large-format marble

Large-format tile is a flatness problem

Large tiles look calm because there is less grout interrupting the surface. What makes them difficult is the same thing: a big rigid tile cannot follow a wall or floor that is not flat, so every deviation in the substrate shows up as lippage — one tile edge standing proud of its neighbour. On a small mosaic that variation disappears into the joints. On a large tile it catches the light along the whole length of the edge.

So the work in a large-format job happens before any tile is set: flattening the substrate, and accepting that this takes longer than it does for small tile. Levelling clips help hold adjacent tiles flush while the mortar cures, but they are a finishing aid, not a substitute for a flat wall.

The other requirement is mortar coverage underneath. A large tile with voids behind it sounds hollow, cracks under point load, and in a wet area gives water somewhere to sit. Back-buttering the tile as well as trowelling the substrate is what gets full contact, and it is the step that separates a tile job that lasts from one that looks identical on the day it is finished.

Linear drains change how a shower floor is built

A traditional centre drain requires the floor to fall towards a point from all four directions, so the shower floor is four planes meeting in the middle. That works, and it is why traditional shower floors use small tiles — they can follow compound slopes.

A linear drain sits along one edge, usually against a wall or at the entry, so the floor becomes a single plane falling in one direction. That single-slope geometry is what allows large-format tile on a shower floor at all, and it is why the two decisions go together.

It has to be planned at rough-in. The drain body and its position are set before the pan is formed. This is not a fitting you choose late.
The slope still has to be under the waterproofing, not just in the tile. The membrane needs to fall to the drain, and the drain has to be integrated into the membrane.
Curbless becomes possible. A single-plane floor draining to one edge is what makes a flush, curbless entry practical, which is the real reason most people end up wanting one.

Why three bathrooms at once is not three projects

Doing several bathrooms together is materially more efficient than doing them one at a time, for reasons that are logistical rather than clever.

One mobilisation. Demolition, disposal, and each trade attending once instead of three times.
One water shutoff plan rather than three separate disruptions to the household.
Tile from one lot. Ceramic and porcelain shade-vary between production runs. Ordering all three rooms together means the material genuinely matches; ordering a year apart frequently means it does not.
One inspection sequence instead of three rounds of scheduling.

The trade-off is that the household loses more bathrooms simultaneously, which is a real consideration and worth planning honestly rather than discovering.

Questions about tile and shower floors

What size tile can go on a shower floor?

With a traditional centre drain, small — the floor has compound slopes and the tile has to follow them. With a linear drain and a single-plane floor, large-format tile becomes possible. It is a geometry question before it is an aesthetic one.

Is a curbless shower harder to build?

Yes, and it is usually worth it. The shower floor has to be recessed relative to the surrounding floor so the fall to the drain begins below the finished level around it. On a raised floor that means framing modification; on a slab it means a recess. Decide early — it is not a late addition.

How do I avoid lippage with big tiles?

Flatten the substrate first, use levelling clips, and set the tile in a running bond of no more than about a third offset rather than a half — large tiles are slightly bowed along their length, and a half offset puts the highest point of one tile against the lowest point of the next.

Does grout colour matter that much?

More than people expect. Grout close to the tile colour makes a surface read as continuous, which is usually the point of large-format. Contrasting grout emphasises the grid, which is a legitimate choice but a different room. Look at the two together, wet, before deciding.

More bathroom remodeling work and our Diamond Bar service area page.

Thinking about a similar project?

We remodel bathrooms across Los Angeles County and the San Gabriel Valley — see bathroom remodeling for how we run the work and where we work for the cities we cover.

The site visit is free and takes about two hours, and you get a written proposal within 48 hours. Call (800) 348-3050 or send us the details. More finished work is on our projects page.