Introduction

If you’re thinking “Renovating my neighbour’s bathroom for free day 3 — what exactly should be finished by now?”, you’re not alone. Day 3 is where good projects either lock in quality or start slipping. Today is all about tanking (waterproofing), tile set-out, and getting the first tiles on the wall without creating headaches later. We’ll also run quick service checks, dial in ventilation, and keep the goodwill project from ballooning. You’ll get a step-by-step rundown, with measurements, tools, and the little pro tricks that stop call-backs.

Quick Answer: On day 3 of “renovating my neighbour’s bathroom for free day 3”, complete substrate prep and tanking, mark a precise tile set-out, fit a ledger batten, and set the first tile courses. Pressure-check plumbing, confirm electrics and ventilation, and document scope so the free job doesn’t creep beyond agreed work.

Table of Contents

• Quick Answer
• Key Takeaways
• Day 3 Objectives
• Waterproofing (Tanking) Done Right
• Tile Layout and First Courses
• Services Checks Before You Cover
• Ventilation, Heating, and Drying
• Managing a Free Job Like a Pro
• FAQ
• Conclusion

Key Takeaways

• Lock in Day 3: tanking complete, set-out marked, and 1–2 tile courses fixed within 6–8 hours of good daylight.
• Use a ledger batten and aim for 2–3 mm grout joints with a 5–8 mm movement gap at edges.
• Let liquid tanking cure 12–24 hours between coats; check coverage at internal corners and penetrations.
• Pressure-check plumbing for at least 15 minutes; confirm RCD protection and correct IP ratings for bathroom zones.
• For goodwill jobs, issue a £0 scoped proposal and get e-signed approval to prevent scope creep.

Day 3 Objectives

Many contractors try to “do it all” on Day 3 and end up rushing waterproofing. Don’t. Today’s goals are simple and critical:

• Finish substrate prep and tanking coats, including corners, niches, and pipe penetrations.
• Mark a precise tile set-out — full tiles on sightlines, small cuts hidden.
• Install a straight ledger batten and set 1–2 courses of wall tile.
• Pressure-check plumbing and verify electrical/ventilation readiness.
• Document what’s done and what’s next, especially on a free job.

If you’re following “Renovating my neighbour’s bathroom for free day 3” as a paced plan, you’ll be in great shape for grout and second-fix later in the week.

Waterproofing (Tanking) Done Right

Substrate and Primer

Problem: Patchy adhesion and leaks start with poor prep.

Solution: Clean, dry, and dust-free surfaces. Use cement backer boards in wet zones and prime per the tanking manufacturer. Reinforce all junctions.

Example: On a shower wall, tape board joints, then brush primer. Embed tanking tape in corners and around the mixer outlet and riser.

Outcome: A continuous, bond-friendly surface that resists moisture ingress.

Applying Liquid Tanking Membrane

• First coat: Brush into corners, then roll large areas. Aim for an even film — no pinholes.
• Reinforce: Use fleece/tape at changes of plane and around every penetration.
• Second coat: Perpendicular to the first. Maintain stated minimum wet film thickness (commonly around 0.8–1.2 mm overall across coats; check the datasheet).
• Curing: Allow 12–24 hours before tiling, depending on temperature and humidity.

A common mistake is leaving dry spots at niches and valve boxes. Go slow here; these spots take on water first.

Sheet vs Liquid Tanking

A quick comparison to help you choose or mix systems smartly:

Tip: Many contractors use sheet on floors with 1:60 fall to the drain and liquid on walls for easy detailing.

Tile Layout and First Courses

Set-Out That Saves You Later

Problem: Slivers and mismatched grout lines scream “DIY”.

Solution: Find the centre line of each wall, dry-lay a row, and balance cuts so you avoid anything less than 30–40 mm at edges. Align verticals with the main sightlines (door, mirror, shower screen).

Example: With 600 x 300 mm tiles, aim for 2–3 mm grout joints. Leave a 5–8 mm perimeter movement gap, to be sealed with silicone later.

Outcome: Clean, professional lines with less rework and fewer awkward cuts.

Ledger Batten and Starting Height

• Fix a straight 25–50 mm batten perfectly level, typically one tile height plus joint above the finished floor line.
• Check your floor fall (for wet rooms, a 1:60 fall is a good target; e.g., about 10 mm per 600 mm run toward the drain). Adjust your first full course height to accommodate floor tile and fall.
• Start tiling on the batten so gravity works with you.

Common mistake: Starting at the floor before the fall and tray levels are locked. Use the batten and come back to the bottom row once the floor is set.

Adhesive, Trowel, and Coverage

• Adhesive: A good C2 TE S1 is commonly used for large-format ceramics/porcelain on walls.
• Trowel: 6–8 mm notch for standard wall tiles; 10 mm if the wall is uneven.
• Coverage: Aim for 80% minimum coverage on walls, 95% in wet areas. Back-butter large tiles.
• Spacers/Clips: 2–3 mm spacers; levelling clips help keep faces true on 600 mm tiles.

Example: Set 2 courses (about 600 mm high with 300 mm tiles) in 2–3 hours, checking plumb every tile with a 600 mm level.

Services Checks Before You Cover

Plumbing Pressure Test

Why it matters: A pinhole behind tiles is a future ceiling stain.

What to do: Cap outlets and pressurise the circuit (cold first), then hot. Hold for at least 15 minutes with no measurable drop. Wipe joints dry first so any weep is visible. Follow manufacturer/supplier guidance for safe test pressure.

Outcome: Confidence to tile over without later tear-outs.

Electrical and Bathroom Zones

• Confirm the circuit is RCD-protected (commonly 30 mA) and isolated while you work.
• Choose fittings with the right IP rating for the zone (e.g., splash areas need higher protection).
• Keep cables routed clear of fixings; mark their position before closing up.

Note: A qualified electrician should certify the work. Don’t tile over access you’ll need.

Ventilation, Heating, and Drying

Moisture management starts now, not at handover.

• Ventilation: In the UK, it’s common to spec 15 litres per second for intermittent bathroom extract fans under Building Regulations. Confirm duct run, backdraft shutter, and a clear path to outside.
• Temporary heat: Mild, even warmth speeds adhesive cure. Avoid blasting heaters that skin surfaces.
• Dehumidifiers: Use where humidity sits high; keep doors open between coats and during cure windows.

Outcome: Adhesives and membranes cure on schedule, grout stays bright, and mould risk drops.

Managing a Free Job Like a Pro

Goodwill doesn’t mean chaos. Scope it like any paid project.

Set Expectations With an E-Signed Scope

• Draft a simple £0 proposal with a clear scope: what’s included today (tanking, set-out, first courses), what’s not (full rewire, moving soil stacks, bespoke niches).
• Use Donizo’s Voice to Proposal to capture details on site, then Send Proposal for e-signature. Even on the FREE plan you get unlimited proposals, e-sign, and PDF export (with watermark).

Result: Everyone agrees the boundaries up front. No awkward chats later.

Track Time, Materials, and Communication

• Snap photos of each stage and attach them to your proposal notes.
• Convert the accepted proposal to an invoice in one click to keep a record (set it to £0). It’s a tidy paper trail.
• On Ascension (paid), add custom branding and use the analytics dashboard to review time/cost trend across goodwill jobs over the year.

Tip: If this turns into paid add-ons, you can issue a fresh proposal from your phone and get it e-signed before lifting a tool. That alone can save 2–3 hours of back-and-forth.

Internal link to explore later: learn more about invoicing.

FAQ

What Should I Complete On Day 3 Of A Bathroom Renovation?

Day 3 is ideal for finishing tanking, marking a precise tile set-out, installing a ledger batten, and fixing the first 1–2 tile courses. It’s also when you pressure-test plumbing, verify electrical/IP considerations, and confirm ventilation. Document scope and progress so tomorrow’s work flows smoothly.

How Long Should Waterproofing Cure Before Tiling?

Most liquid tanking systems need 12–24 hours between coats and before tiling, depending on temperature and humidity. Always follow the product’s datasheet. Check corners, penetrations, and niches for complete coverage and make sure the membrane is fully dry before adhesive goes on.

Should I Start Tiling From The Floor Or A Ledger Batten?

Use a ledger batten. Set it perfectly level at one tile height plus joint above the finished floor line. This keeps courses dead straight and allows for floor falls and tray levels. Return to the bottom row after the floor is tiled and cured, maintaining a 5–8 mm movement gap at the perimeter.

What Grout Joint Size Works Best For 600 x 300 Tiles?

A 2–3 mm grout joint is common for 600 x 300 mm rectified tiles. Ensure walls are flat, use the right notch trowel (6–10 mm depending on flatness), and consider levelling clips to keep faces flush. Maintain at least 80% coverage on walls, 95% in wet areas.

How Do I Stop A Free Bathroom Job From Growing In Scope?

Issue a £0 proposal with a crystal-clear scope and get it e-signed. Note what’s excluded. In Donizo’s FREE plan you can create unlimited proposals with photos, send for approval, and store an e-signed record. If extras pop up, send a new proposal before doing the work.

Conclusion

Day 3 is the pivot point: tanking complete, set-out locked, 1–2 tile courses on, and services checked. Stick to the basics — 2–3 mm joints, 5–8 mm movement gaps, 12–24 hours tanking cure, and at least 15 minutes of plumbing pressure hold — and the rest of the week runs clean. If you’re doing this as a goodwill project, protect yourself with a £0, e-signed scope. Donizo makes that easy with Voice to Proposal, e-signatures, and one-click invoice records. Try the FREE plan to keep today tight and tomorrow tidy.