Floor Moisture Testing Questions Checklist

Write down every leak, overflow or flood you know of in this room, including ones dealt with long ago and ones that happened before you moved in.

A history that seems irrelevant to an owner is often the first thing a flooring specialist wants to hear about.

Note any patch of floor that feels colder underfoot than the rest, and mark roughly where it is on a sketch of the room.

Cold areas are frequently where a professional would choose to measure, and they are easy for an owner to feel.

Look at the existing covering for curling edges, lifting corners, discoloured patches or a musty smell, and photograph what you find.

The failing covering is evidence in itself, and photographs survive after it has been ripped out and skipped.

Note whether the room smells different after it has been closed up for a while, and whether that changes with the weather.

A smell that comes and goes with the weather is the sort of observation only somebody living in the house is in a position to supply.

Say what lies below this floor if you know, whether that is a cellar, a void, a garage or the ground itself.

What is underneath changes both where moisture might come from and how a measurement is likely to be taken.

Note whether the ground outside this part of the building sits above or below the level of the floor inside, and record what you observe.

This is one of the few things about a floor that an owner can look at from the garden without any equipment.

What ground levels outside mean for a floor is for a qualified professional to establish, so record what you see rather than drawing a conclusion.

Ask who will be taking the reading, whether that is the flooring contractor, the builder or somebody independent of both.

Naming the person early prevents the familiar situation where each party assumed the other had done it.

Ask whether taking readings is included in what you have been told, or whether it is treated as separate work to be agreed later.

Measurement is small enough to be left out of an early conversation and important enough to stop the job.

Ask at what point in the work the reading is taken, and whether anything wet is still to happen in the room afterwards.

A reading taken before plastering or before a levelling layer goes down says very little about the floor that will receive the covering.

Ask whether the person taking the reading is also the person whose warranty depends on the result.

It is a fair question asked calmly, and the answer tells you whether a second opinion would be sensible.

Where the same party measures and then relies on the result, consider asking a qualified independent professional to take a reading as well.

Ask what happens if nobody takes a reading at all, and who would carry the consequence if a problem later appeared.

Skipping the measurement is a decision even when it is never spoken about, and it is better made in the open.

Ask whether the manufacturer of your chosen covering requires a reading before their material may be laid.

This turns an optional-sounding step into a condition, which changes the conversation entirely.

What a manufacturer requires before their product is laid is set out in their written instructions, so ask for that document rather than relying on what you were told.

Ask what method is being used and whether it measures the surface or the material further down.

A surface reading and a deeper reading can tell quite different stories about the same floor, taken in the same room by the same person.

Ask in how many places across the room readings are taken, and whether the corners and the middle of the floor are among them.

A single reading in a convenient spot is the least useful version of this exercise and the most common.

Ask whether readings are taken where the base is most likely to be wet, such as against an outside wall or near a former leak.

This is where the history you wrote down earlier earns its place in the conversation.

Ask how areas under fitted units, a bath or a stair are dealt with, since those parts of a floor are rarely reachable.

Concealed areas dry differently from open ones and are exactly where a problem can sit unnoticed.

Ask whether the room needs to be closed up or at a particular temperature while the reading is taken.

Conditions affect what is measured, and an owner airing the room out of helpfulness can change the result.

Conditions during measurement are set by the person taking the reading, so ask what they need rather than arranging the room yourself.

Ask whether the method leaves a mark or a hole in the base, and whether that matters for the covering going over it.

Some methods are not invisible, and it is better to know that before a finished surface is involved.

Ask what the reading is being compared against, and ask to see that requirement in the manufacturer literature for your covering.

The comparison is where the judgement actually happens, and it should be a document rather than an opinion.

What a reading is judged against comes from the manufacturer of the specific covering, so ask for their document rather than accepting a general threshold.

Ask what this result means for the particular covering you have chosen, since coverings differ in what they tolerate.

The same base can be ready for one material and not for another, which owners rarely expect.

Ask whether a reading that is acceptable for this covering would also be acceptable for the alternatives you are still considering.

If a base is marginal, this question can quietly redirect the whole choice of floor.

Ask what the reading does not tell you, and what else the person measuring would want to know about this floor.

A reading answers one narrow question, and the useful conversation is usually about everything around it.

Ask whether this is a snapshot or whether readings need repeating to show which way the floor is going.

A base that is drying and a base that is getting wetter can give the same reading on a single visit.

Ask what could change the reading between the day it is taken and the day the covering actually goes down.

Other trades, weather and open doors all affect a base, and the gap between measuring and laying is rarely nothing.

Ask what happens if the base is not ready, and who decides whether the work waits.

Naming the decision maker in advance stops it being made by whoever is standing in the room with a van outside.

Ask whether any form of forced drying is being suggested, what it involves, and what your covering manufacturer says about it.

Drying a base quickly can affect the base itself, so the covering manufacturer position on it is worth having.

Whether a base may be dried by artificial means is a question for a qualified professional and the material manufacturer, not a decision to take on site.

Ask what waiting would mean for the rest of the work in the house, and write down what everybody agrees to do.

Most pressure to proceed comes from trades waiting on each other rather than from anybody believing the base is fine.

Decide and record whether you are willing to have a covering laid over a base that has not met the requirement.

This is an owner decision with consequences, and it should exist in writing rather than as a shrug on the day.

If a covering is laid over a base that has not met the manufacturer requirement, ask in writing who carries responsibility for the outcome.

Ask what typically goes wrong when your particular covering is laid too early, and what that looks like when it happens.

The failure mode differs by material, and hearing it described makes the risk concrete rather than theoretical.

Ask whether the room can be left open and warmed while it dries, and who is responsible for keeping that going.

Rooms are often shut up and unheated between trades, which is the opposite of what a drying base needs.

Ask whether a surface applied barrier is being suggested, what it is said to do, and just as importantly what it does not do.

Barriers are often presented as a solution to everything, and the limits are the part worth writing down.

Ask whether your covering manufacturer accepts that barrier beneath their product, and ask for that acceptance in writing.

A barrier the covering manufacturer does not accept can quietly remove any protection you thought you had.

Acceptance of a barrier by the covering manufacturer is a written matter, so ask for their statement rather than relying on somebody saying it will be fine.

Ask what happens to the moisture the barrier holds back, and where it goes instead.

Moisture that is stopped in one place usually appears in another, often at the edges of a room.

Ask whether choosing a different covering would remove the problem altogether, and what that would change for you.

Changing the material is sometimes simpler than engineering around the base, and it is rarely offered unprompted.

Ask whether the barrier or any levelling over it changes the depth of the floor build-up at doors and thresholds.

Solutions applied to a base add depth, and doors are the first place that shows.

Ask what the barrier means for lifting the covering later, and for any future work on this floor.

A bonded build-up is harder to take up, which matters if the room is likely to change again.

Ask for the reading in writing, with the method used, where in the room it was taken and when.

A verbal reassurance that the floor was fine is worth very little once a covering has started to lift.

Keep the manufacturer document setting out what the base has to achieve alongside the reading itself.

The reading and the requirement only mean something as a pair, and they are usually filed separately or not at all.

Write down who took the reading and in what capacity, and keep that note with your other papers for the work.

Responsibility is much easier to establish while everybody is still on site and cooperative.

Ask what the covering warranty depends on in terms of the base, and keep that answer with the rest of the file.

Warranties frequently rest on a condition about the base that nobody mentioned at the point of ordering.

Warranty conditions are set by the manufacturer, so ask for the written conditions rather than a summary of them from a supplier.

Note what everybody agreed to do if a problem later appears to come from moisture in this floor.

Agreeing the route back before anything goes wrong is far easier than negotiating it afterwards.

Ask whether readings should be repeated once the covering has been down for a while, and whether that is even possible.

Some build-ups can be checked again and some cannot, which is worth knowing before the floor closes over.