Bathroom Renovation Vol.8: Floor Base Preparation

u270fufe0f Originally published: 2016-11-30 / ud83dudd04 Updated: May 8, 2026

2026 Update from DIY Dad: Bathroom/Laundry Room Renovation Strategies

The bathroom/laundry room is one of the more challenging DIY projects because of its wet-area nature u2014 but with the right approach, it’s absolutely doable.

Floor Work in the Bathroom/Laundry Room

The biggest challenge in this series was the full floor replacement: checking for joist rot u2192 repairs u2192 plywood subfloor u2192 cushion floor finish. This is among the more difficult DIY tasks in wet-area renovation.

What to Check Before Laying the Subfloor

• Measure joist spacing (typically 303mm = 1 shaku)
• Check joists are level with a spirit level
• Visually inspect and press-test for rot or termite damage
• Lay plywood sheets in a staggered pattern so seams don’t line up

Without staggering, all seams fall in a straight line and the floor clunks when walked on. DIY Dad caught this on the very first sheet and fixed it.

Tips for Laying Cushion Floor

• Make a paper template (trace the floor shape using roll paper or cardboard)
• Cut cushion floor 5u201310mm oversize, then trim to final fit on site
• Cut wall edges straight down with a utility knife (not at an angle)
• Spread adhesive evenly with a notched trowel, then press down while rolling out air
• Reinforce seams with seam-specific adhesive if the floor has joints

The bathroom/laundry room has a complex shape u2014 taking a careful paper template is the key to success.

Installing the Washing Machine Stand

Always confirm the floor is level before setting the waterproof pan. Also verify drain hole alignment and drain hose reach.

What DIY Dad Prioritizes as a Landlord

• Use seamless sheet cushion floor for easy maintenance
• Choose a washing machine pan shape that’s easy to clean
• Always verify the ventilation fan is working u2014 essential for mold prevention
• Caulk carefully at all vanity, pan, and wall joints

The cleanliness of the bathroom/laundry room directly affects occupancy rates. Cutting corners here always causes problems at move-out.

ud83dudebf For Anyone Considering a Vanity or Wet-Area Renovation

Confirm drain pipe types and measurements before starting to avoid leaks.

Floor Base Preparation u2014 Patching & Surface Leveling

Hi, this is DIY Dad! Continuing the first-floor bathroom/laundry room renovation series.

Next up: filling and leveling the irregular floor surface with patching compound before the cushion floor is laid. Tools and materials used: patching compound and a trowel/spatula.

The disc grinder left a large area of gouged surface, so patching compound is applied over the entire floor.

u2191 The full floor surface.

u2191 From a different angle.

DIY Dad has gotten much more comfortable with patching compound at this point. Early on, getting the water-to-compound ratio right was unexpectedly tricky u2014 batches would come out too runny or too dry. But with practice it becomes natural.

Using Patching Compound to Repair a Wall Hole

DIY Dad tried an improvised approach here u2014 using patching compound almost like mortar to fill a hole in the wall left when the baseboard trim was removed and the wall was damaged.

u2191 The wall hole before repair.

The cracked gypsum board piece is fitted back into the hole as a filler.

u2191 Temporary fill with the gypsum board fragment.

u2191 After patching compound is applied over the repair.

u2191 Pulling back for a wider view.

It may not be textbook technique, but the hole is filled u2014 and that’s good enough for now! That’s all for today u2014 see you next time!

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