Home Improvement Bathroom: Contractor’s Remodel Guide

Intro

On most jobs, the Home Improvement & Bathroom work is the trickiest. Tight spaces. Wet zones. Many trades in one room. Clients expect a “show home” finish. This guide gives you a clear path. What to plan, how to waterproof, when to tile, and how to hand over. We use simple steps and real measurements. You’ll see the common mistakes and how to dodge them. Follow this and your Home Improvement & Bathroom projects run smoother, with fewer snags and faster payment.

Quick Answer

A solid Home Improvement & Bathroom job starts with a clear layout, proper waterproofing, and the right ventilation. Set correct falls (10–15 mm per metre), use backer boards, tank wet zones, and size extraction at 15 l/s. Plan 7–10 working days, manage change orders, and hand over with a snag list and care guide.

Table of Contents

• Key Takeaways
• Plan The Home Improvement & Bathroom Scope
• Waterproofing That Never Fails
• Services: Plumbing, Heating, And Ventilation
• Tiling, Trays, And Wet Rooms
• Home Improvement & Bathroom Time, Budget, And Clients
• Snagging And Handover
• FAQs
• Conclusion

Key Takeaways

• Set shower falls at 10–15 mm per metre; soil gradients at 1:80–1:40.
• Use 12 mm tile backer on 400 mm centres and tank Zones 1–2.
• Ventilation at 15 l/s with a 10–15 minute run‑on cuts mould risks.
• Typical full refit: 7–10 working days with 2–3 site visits by client.
• Rapid‑set adhesives cure in 3–4 hours; silicone needs 24 hours before use.

Plan The Home Improvement & Bathroom Scope

A tight plan saves days later. Use this checklist before you touch tools.

1. Confirm the layout

   • Bath: 1700 x 700 mm is common. Shower: 900 x 900 mm works in most rooms.
   • WC projection: 550–600 mm. Basin front clearance: 450 mm; 200 mm to side wall.
   • Keep the 110 mm soil branch as straight as possible (1:80–1:40 fall).

2. Measure services

   • Cold/hot supplies: 15 mm pipes suit most basins and WCs. Check pressure (1–3 bar).
   • Wastes: 32 mm basin, 40 mm bath/shower, 110 mm soil. Protect falls.

3. Mark heights

   • Vanity top: 850–900 mm. Shower valve: 1000–1200 mm. Head: 2000–2200 mm.
   • Towel rail bottom: 150–200 mm from floor. Mirror centre: about 1500 mm.

4. Set electrics plan

   • RCD at 30 mA. Respect zones: 0 (IPX7), 1 and 2 (IPX4). No sockets in Zones 1–2.
   • Choose an extractor fan location with a 3 m max duct where possible.

5. Choose finishes

   • Tiles: agree size and joint (2–3 mm). Discuss trims or mitres.
   • Waterproof system: sheet or liquid. Confirm brand, coats, and cure times.

6. Scope the programme (7–10 working days)

   • Demo: 1 day. First fix: 1–2 days. Boarding/tanking: 1 day.
   • Tiling: 2–4 days. Second fix: 1–2 days. Snags/silicone: 0.5–1 day.

7. Price and paperwork

   • List provisional sums (PC items) for brassware, tiles, and furniture.
   • Capture site photos and voice notes; tools like Donizo help you turn voice, text, and photos into a clean proposal fast, then send it for e‑signature.
   • For more detail on creating professional proposals and managing project timelines, see our guides on professional proposals and project timelines.

Waterproofing That Never Fails

Water is the silent killer. Get the envelope right first, then tile.

Know the zones

• Zone 0: inside bath/shower. Needs IPX7 fittings and full tanking.
• Zone 1: above bath/shower up to 2250 mm. Tank and use IPX4 kit.
• Zone 2: 600 mm around bath/shower edges. Tank splash areas too.

Board and prep

• Use 12 mm tile backer on studs at 400 mm centres. On solid walls, 6 mm is fine.
• Prime dusty surfaces. Stagger joints. Tape all seams and corners.

Tanking steps (liquid system)

1. Brush coat 1 on walls and floor in wet areas (aim for even coverage).
2. Bed sealing tape on all internal corners, niches, and board joints.
3. Fit collars on pipes and wastes; seal tight.
4. Apply coat 2 at 90° to coat 1. Let each coat cure 4–6 hours.
5. Wait 24 hours before tiling. Don’t rush this. Most contractors who do regret it.

Falls and thresholds

• Wet room falls: 10–15 mm per metre to the drain.
• Keep door thresholds level with outside floor; use a former or ramp under tile.
• If using a tray, bed it in full‑coverage adhesive or mortar. No voids.

Common mistakes

• Plasterboard in showers. It swells and fails.
• No movement joint around the perimeter. Tiles pop.
• Tanking after fixing the tray. Always tank first or integrate properly.

Services: Plumbing, Heating, And Ventilation

Get services right and call‑backs drop.

Plumbing

• Pressure: 1–3 bar suits most mixers. Fit pressure‑reducing valves if needed.
• Pipe runs: keep hot and cold apart by 50 mm to reduce heat transfer.
• Wastes: keep to 3–4 bends max; maintain 18–25 mm fall per metre on 40 mm waste.
• Test: pressure test for 10–15 minutes before closing walls. No drips allowed.

Heating

• Electric UFH: 150 W/m² is typical. Use 10 mm insulation boards under.
• Resistance test before and after tiling. Photograph readings for records.
• Radiators/towel rails: balance system and bleed. Check TRVs open.

Ventilation and electrics

• Extractor: 15 l/s intermittent with a 10–15 minute overrun (Part F guidance).
• Ducting: rigid where possible, max 2–3 bends, seal joints, slight fall to outside.
• Lighting: IPX4 in Zones 1–2. Use warm 2700–3000 K for comfort.
• Circuits: RCD 30 mA and bonding as required. Always test and certificate.

Tiling, Trays, And Wet Rooms

This is what clients stare at every day. Make it perfect.

Layout and setting out

• Dry lay first. Centre on the main wall or niche. Avoid 10–20 mm slivers.
• Keep grout joints constant at 2–3 mm. Use levelling clips only to assist, not to fix bad prep.

Adhesives and grout

• Use C2 flexible adhesive on backer boards and UFH. Rapid‑set cures in 3–4 hours; standard in 16–24 hours.
• Porcelain needs a solid bed. Back‑butter big tiles (600 x 600 mm+).
• Movement joints every 3–4 m or at changes of substrate. Silicone perimeter.

Build a fail‑safe shower area (How‑To)

1. Install former or set tray level, fully bedded.
2. Fit waste and test with 10–15 litres of water.
3. Board walls with 12 mm backer; tape/skim joints with waterproof tape.
4. Tank two coats with corners/collars sealed.
5. Set out tiles from centre; cut full‑height around niche.
6. Tile walls first, then floor. Maintain 2–3 mm joints.
7. Grout after adhesive cures. Clean lines. No pinholes.
8. Fit screen with seal; avoid drilling into tray upstands.
9. Silicone internal corners and edges; let cure 24 hours.
10. Run shower for 5 minutes to check drainage and seals.

Home Improvement & Bathroom Time, Budget, And Clients

This is where many jobs lose margin. Stay on top of it.

Timeline and sequencing

• Typical full refit: 7–10 working days. Add 1–2 days for plastering or levelling.
• Book deliveries 1–2 days before fitting. Store tiles flat. Check quantities.
• Keep clients to 2–3 site walk‑throughs: day 1 (layout), mid‑tiling, pre‑handover.

Budget control

• Separate labour, materials, and PC sums. Write clear inclusions/exclusions.
• Use written change orders for any deviation. Price time and materials. For help, see our guide on change orders done right.
• Send tidy, branded proposals and collect signatures fast. Platforms such as Donizo let you capture details, send proposals for e‑signature, and convert to invoices in one click. Pair this with strong invoice templates and clear pricing strategies.

Communication

• Share 3–5 progress photos across the job. Clients relax when they see work.
• Confirm choices in writing: tile pattern, trim colour, silicone colour, grout colour.
• If you’re also improving client management, our tips on client updates and project timelines will help.

Snagging And Handover

Finishing well gets 5‑star reviews and fast payment.

Snag pass

• Wipe tiles with a damp microfibre. Check all joints for pinholes.
• Fill bath to check silicone under load. Then drain and inspect.
• Run extractor for 10 minutes. Feel airflow outside.
• Flush WC 3–5 times. Check for sweats and weeps.

Handover pack

• Care sheet: no bleach on silicone; wipe screen daily; clean grout weekly.
• Valve instructions and warranties. Note stopcock location.
• Defect period: state 12 months workmanship as standard (adjust if different).
• Final photos and a simple snag sign‑off sheet. This reduces disputes.

Conclusion

A clean Home Improvement & Bathroom job comes down to planning, waterproofing, smart services, and tidy finishes. Set the right falls, tank wet zones, and control the programme. Next steps: 1) Walk your next site with this checklist, 2) Agree finishes and zones in writing, 3) Send a clear proposal and change order process. If you want to speed up admin, solutions like Donizo help capture details, send proposals for e‑signature, and invoice fast. Do the basics well and your bathrooms will last, look sharp, and get you referrals.