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Don’t Let Moisture Bite You On The Bum

A great deal is regularly written in the CFJ on moisture, its measurement, all the implications and how to deal with it, so it doesn’t jump up and bite you on the bum.

Most of this industry’s acknowledged experts have written pieces published in this respected flooring journal concerning many aspects of the subject, including myself, (a definition here: An expert is a drip under pressure – old schoolboy joke but you see the connection with water!)

Seriously, do remember that moisture issues are the number one cause of all flooring failures and problems. At this juncture it is perhaps worth summarising just what a floor failure due to moisture actually costs.

Imagine, if you will, that you have won the business to supply and fit a new solid oak floor in a ground floor room of a big house. The room measures 5m x 10m, so we are talking about a 50sq m installation.

Typical costs may be as follows: Oak floor £30sq m £1,500 Adhesives, underlayments, fittings £7sq m £350 Labour £15sq m £750 Total (without liquid dpm) £2,600

Then you hear that there has been a failure due to moisture. All of the above material has to be removed and replaced with the addition ofadpmatsay£6sqm.Sowearetalkingofa further £2,600 + £300 for dpm.

Your total for this job ends up at £5,500 plus extra time when you could have been doing the next installation, but perhaps most importantly, the cost to your reputation. When things go wrong your company will be talked about. However, when they go right (hopefully most of the time!) you will be lucky if it gets a brief mention.

The worrying fact is that most fitters do not fully understand how their moisture meters work and the significance of what it tells them. That is assuming that they have a moisture meter in the first place, which many do not. Hard to believe, but true!

Getting booked on a moisture course will be your best insurance policy to ensure this does not happen to you. Over the years I have run moisture appreciation courses, it has become apparent that the practical aspects of what instruments to use and how to interpret the readings is, perhaps, the most valuable part of the course.

Furthermore, the syllabus of the FITA course run at Loughborough has been modified to encompass a much more practical hands on experience outside of the lecture room. The course, ‘Understanding Moisture’ reflects this and delegates are asked to bring along their moisture meters and hygrometers so they can be instructed on their practical use on subfloors.

Do not worry if you don’t have these instruments as some will be available for use on the day and, as a course attendee, you will be entitled to a discount on new instruments and accessories, as a benefit of FITA negotiating deals with manufacturers. There is also the advantage of free technical telephone support from me which you won’t get from any internet moisture meter re-seller. Here endeth the commercial!

To conclude this month, I will re-visit the story of a problem with a wood floor I was asked to look at from the moisture perspective working alongside another independent consultant.

It was an engineered walnut floor replacing old carpet over hardboard. Initially for a few months all was well, but after some exceptionally wet summer weather (not thought of as causal or significant at the time), this floor started to move and bow upwards.

When I got to site I noted that the property sat at the bottom of sloping ground. Outside the little French drainage that existed was partially obscured by leaves and vegetation up to the level of the damp proof course. The soil in the garden was heavy clay and lying quite wet.

This had all the makings of a situation that would see moisture migrating into the walls at low level and on or just above the damp proof course. The wood was installed over a Cellotex membrane which was, in turn, installed over the previously sound hardboard.

This could breathe with the old carpet on top, but now the Cellotex was trapping the moisture which had migrated from the wall into the subfloor: It was the hardboard expanding and bowing which caused the engineered walnut to move in sympathy.

When boards were lifted inside it was discovered that the Cellotex membrane had been installed upside down AND the joins were not taped! This allowed moisture in the subfloor to migrate upwards into the timber (but in the main the walnut was dry) with the aforementioned result.

The case went to court and the fitter was held responsible and it cost him £5,000. Hindsight, as we know, is a wonderful thing. But had he been up to speed and ‘tough on damp and tough on the causes of damp’ (to paraphrase an old political sound bite) the problem would have never happened, notwithstanding the exceptional summer rainfall that year.

The moral here is to get yourself on that moisture course and save money – you know it makes sense!
Peter Grant Consultancy & Contractor Services

T: 01780 410588
Mobile: 07885 221675

‘This course can save you loads of money!’

THERE is still time to book onto the FITA Understanding Moisture course at the FITA centre in Loughborough on July 11. Book now, it could save you hundreds or pounds!

I Understanding Moisture: This comprehensive one-day course is intended for contracts managers, estimators, fitters or after sales people to identify moisture effectively.

The course will help you to understand your responsibilities and to ensure that a new floor needs to be installed only once.

A failed floor always has the potential to be costly. Ensure a trouble-free experience for both you and your client by attending this course.

Topics covered during the day include: I Health and safety I Customer relations I British Standard
I ‘The FITA Way’:

o The impact of moisture; and

o Preventing installation failures. I Subfloor types and construction:

o Solid; and

o Wooden I Subfloor moisture testing:

o Equipment; o Test methods;

o Logging/evaluating results; and

o Practical testing and analysis

I Building construction:

o Identifying tell-tale symptoms
I Understanding site conditions:

o Creating the right solution; and

o Scenario based learning

I Technical support: o Selecting the right system
I Role of the manufacturer
For details, prices and to reserve a place contact FITA:


This article has been reproduced from the Contract Flooring Journal website. You can find them at