Tiler Waterproofing Checklist: Record the Substrate Before Tiling

The membrane is already down when your crew arrives. There are no labelled photographs of the substrate, the joints are hidden and nobody will accept the earlier work. A tiler waterproofing checklist gives you a hard stop before tile conceals the evidence.

Treat that stop as part of the job. Record what you saw. State what was already concealed. Assign defects. Release each room or surface separately.

Use the tiler waterproofing checklist to fix the scope

Start with the accepted quote and current job documents. Identify the rooms and surfaces covered by the tiling scope. Then separate substrate preparation, waterproofing and tile installation.

Do not let a single line marked “bathroom tiling” carry all three stages. It leaves the crew guessing who repairs damaged board, who tanks the shower and who accepts the surface before adhesive is mixed.

Use the same room and surface names across the quote, drawings, photographs, defects and work order. “Upstairs shower, valve wall” is useful. “Bathroom wall” is not.

Decide what must be waterproofed

Tile and grout do not waterproof a shower. The specified water-resistant or waterproofing build-up must be complete before tiling. Its exact extent comes from the current design, system instructions and applicable local requirements.

Where the documents do not answer the question, ask the designer or specifier. Keep the affected area on hold until the answer is written down.

Assign responsibility for each stage

Separate the business doing the work from the person checking it and the person authorised to release it. Complete one row for every named area.

A waterproofing installer applying membrane does not automatically settle every question about the substrate below it. Your tiler substrate inspection does not make you responsible for work that another trade completed before your arrival.

If a shower wall uses a different board or background from the current job documents, stop. Photograph the whole wall and the transition. Ask the customer, main contractor, designer or site manager named on the job to assign the correction or accept the revised detail in writing.

Put the right records on the tiler pre-start checklist

The crew needs the documents that define the work. Tile, adhesive, access and a booked start date are not enough.

Put these records on the tiler pre-start checklist:

• The accepted quote and current work order.
• Current drawings and specifications.
• The agreed room and surface names.
• Instructions for the specified substrate, waterproofing and adhesive system.
• Scope inclusions and exclusions.
• The exposed-substrate inspection record.
• Waterproofing records supplied by another party.
• Defect, correction and recheck records.
• The internal release for tiling.
• The building regulations position, responsible body and reference, where that approval question applies.
• For hazardous substances and work that require assessment, the applicable RAMS, COSHH assessment and current safety data sheets; use the Health and Safety Executive (opens in a new tab) in Great Britain or the Health and Safety Executive for Northern Ireland (opens in a new tab) for workplace safety questions.

Use the work order template to give the crew the accepted scope, document references and held areas before they travel to site.

Do not copy curing periods, test methods, coverage requirements or acceptance limits from an old form. Take them from the current job documents and current instructions for the specified system. Write down the document or instruction used.

Copy-ready waterproofing release record

Keep the form short enough to complete on site. Attach photographs and longer defect notes rather than squeezing everything into one box.

TILER WATERPROOFING RELEASE RECORD

Job:
Address:
Room or area:
Surface or detail:
Inspection stage: [Exposed substrate / Visible waterproofing / Ready for tiling]
Inspection date:
Checked by:
Role and business:

JOB DOCUMENTS
Accepted quote or work order:
Drawing revision:
Specification revision:
System instructions used:
Scope for this stage:
Work assigned to another party:
Building regulations position: [Not established / Not required / Required / Pending / Approved]
Responsible body and reference:

SUBSTRATE RECORD
Substrate type and exact location:
Visible condition:
Repairs or surface treatments:
Dust, residue, coatings or contamination:
Joints and material transitions:
Corners and changes of plane:
Drains, pipes and penetrations:
Damage or later alterations:
Job-specific measurement required:
Tool, location and result:
Requirement used for acceptance:

WATERPROOFING RECORD
Installed by:
Areas personally observed by us:
Areas already concealed:
Records supplied by another party:
Visible junctions and penetrations:
Visible damage or contamination:
Later fixings, holes or alterations:
Release requirement taken from:
Compatible products and instruction used:

DEFECT AND CORRECTION
Defect reference:
Exact location:
Condition found:
Correction owner:
Required correction:
Inside accepted scope: [Yes / No / Not decided]
Variation required: [Yes / No]
Recheck date:
Recheck result:

AREA STATUS
[Released for tiling]
[Released with the named condition below]
[Stopped pending correction, evidence or approval]

Named condition or reason for stop:
Why work can proceed without concealing or blocking the outstanding item:
Hold boundary:
Released by:
What this person inspected or approved:
Date:
Photograph references:

The completed tiler waterproofing checklist must identify the stage being signed. A substrate observation, review of supplied records, visible membrane inspection and release for tiling are different decisions. Do not hide them behind one broad signature.

Run the tiler substrate inspection while everything is exposed

Inspect the substrate before membrane hides joints, repairs and transitions. Walk every named wall and floor. Make a separate entry when the substrate changes.

Record what you can see:

• Loose, cracked, broken or damaged material.
• Dust, residue, coatings and other contamination.
• Patches, repairs and filled areas.
• Board joints and transitions between materials.
• Wall-to-floor junctions.
• Internal and external corners.
• Changes of plane.
• Drains, pipes, valves and other penetrations.
• Holes or damage caused by later work.

Do not write “substrate acceptable” without supporting detail. Name the surface, condition and document used for the decision.

Record measurements against a stated requirement

Measure moisture, falls, planes, levels or other conditions only where the job documents or specified system require them. Record the tool, exact location, result and acceptance requirement.

A result without a location is weak. A result without the requirement used to judge it is weaker. Do not invent a limit when the current documents are silent. Ask the designer, specifier or other named decision-maker and keep the area held.

The tiler waterproofing checklist should also show where no measurement was required. That prevents a blank box from being mistaken for a missed check.

Decide whether primer is required for this system

Do not prime by habit. Identify the substrate, waterproofing product and adhesive that form the specified system. Read their current instructions together.

The answer can change with the surface, product and stage of work. A primer used beneath waterproofing is not automatically the product required over a membrane before tiling.

Record the product identity and the instruction used. If the installed membrane cannot be identified, stop. If the substrate, membrane and adhesive instructions conflict, send the question to the designer or specifier. Do not guess and cover the problem.

Where another trade claims that a primer was applied, ask for its product and application record. Label that information as supplied by the other party. Do not present it as something your crew observed.

Build tile waterproofing records that identify the detail later

Take a location photograph first. It should show the room and enough surrounding area to find the surface again. Then take a close detail photograph of the joint, corner, penetration, repair or defect.

Give each image:

• The job reference.
• The room and surface name.
• The work stage.
• The date.
• A matching checklist or defect reference.

A close photograph of a pipe penetration is poor evidence if nobody can tell which wall it belongs to. A wide room photograph is poor evidence if the defect cannot be seen. Use both.

Take separate photographs before correction and after recheck. Keep the original defect reference on both records.

A photograph records only what was visible from that position at that time. It does not reveal how a concealed board joint, repair or transition was prepared.

When the membrane was installed before your arrival, state that the original substrate was concealed and was not inspected by your business. Ask for the earlier substrate record, labelled photographs, waterproofing application record, required test record and correction evidence.

Label every document and photograph from another party as a supplied record. Record who sent it and when it arrived. Keep it separate from observations made by your crew.

Useful wording is direct:

Visible waterproofed surface inspected by our business.
Original substrate and concealed preparation were not observed by us.
Supplied records are listed separately below.

Missing evidence can be a stop condition. Booked labour and delivered tile do not make concealed work acceptable.

Inspect the waterproofed surface as a separate stage

Do not combine the substrate inspection and membrane inspection. They answer different questions.

Once waterproofing has been applied, inspect the visible surface against the current job documents and specified system. Check visible junctions, changes of plane, penetrations, drains, edges, contamination and later damage.

Look for fixings, pipe changes or holes added after waterproofing. A damaged area that will sit behind the next tile needs a named correction and recheck before it disappears.

Record any test required by the job documents. Name the method, responsible person, record reference and result. Do not invent a test or duration from memory.

UK site block: Keep your release separate from official approval

Use UK job language in the checklist and linked records. Write labour, not labor. Call added work a variation.

Your internal release answers one question: will your tiling business cover this area? A building regulations approval or inspection answers a separate question. Do not combine the records or describe your checklist as an official approval.

For a job in England, ask building control about building regulations approval (opens in a new tab). For work in Wales, ask building control about building regulations (opens in a new tab). In Northern Ireland, check the official building regulations guidance (opens in a new tab). For a Scottish job, ask building standards about the building warrant process (opens in a new tab).

Write down whether the question was raised, who answered it and the building control or building standards reference. Do not copy the status from a casual site conversation.

Keep the entries narrow:

• Internal substrate observation.
• Waterproofing record supplied by the installer.
• Internal visible-membrane inspection.
• Official building regulations record, where required.
• Release from the customer, main contractor, designer or site manager named on the job.
• Your supervisor’s release to the tiling crew.

Your internal hold point still matters when no separate official inspection is required. It controls what your business is prepared to conceal.

Give each room or surface a clear release status

Use one status for each named area.

Released for tiling

Use this when the required checks and records are complete, visible defects have been dealt with and the authorised person has released that area.

Name the person and state what they approved. “Released by site manager” is not enough if it is unclear whether they reviewed supplied records or only looked at the finished membrane.

Released with a named condition

Use this only when work can proceed without hiding or blocking the outstanding item. Name the condition, its owner and the point at which it must be closed.

Do not write “minor items outstanding”. State the exact room, surface and item. If tiling would conceal the condition, the area is not ready for a conditional release.

Stopped pending correction, evidence or approval

Use this when a defect affects the proposed installation, required evidence is missing, waterproofing has been damaged or the authorised person has not released the stage.

Mark the held area on the work order. Tell the crew what other work can continue. Keep tile and adhesive out of the stopped area until the correction has been rechecked.

Turn a failed check into a correction or variation

Compare the defect with the accepted quote before anyone starts repairing it. The correction may belong to your business, another trade, the customer or the main contractor. Assign the owner in writing.

If the accepted quote covers tile installation but excludes substantial substrate repair, do not absorb the repair because the crew is already there. Describe the location, condition, proposed work and effect on the sequence. Price the labour, materials and markup using your own costs, then obtain written approval as a variation.

The guide to writing a quote helps you separate preparation, waterproofing, tiling and exclusions before the work reaches site.

Worked example: control the extra before completing it

The Oak Street electrical job is the house example for added-work control. It is not a tiling price or rate card. All figures are sample currency units.

Quote Q-1847 for R. Chen at 14 Oak Street covered a bathroom exhaust fan and four LED downlights for 1,105. The ceiling was lined, and the quote excluded chasing. Extra cable and chasing were approved on site as a 160 variation. Invoice INV-1847 was then 1,265.

The lesson for the tiling job is simple. If unexpected substrate repair sits outside the accepted scope, stop. Write the variation. Get approval. Then repair and recheck the surface.

Code unquoted preparation separately in your cost tracking. Otherwise booked labour disappears into the tiling line and weakens job profitability without showing why. Use the job-costing guide to compare the accepted scope with the labour and materials actually used.

Hand the released record to the crew before tile enters the area

Attach the tiler waterproofing checklist, photographs, supplied records, defects, corrections and release to the same job. Use the same area names on every document.

The crew should be able to open the job and see which surfaces are released. Held areas stay off the work plan until the named correction is complete and the recheck has been recorded.