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The Customer Isn't Always Right!

5/22/2015

As a flooring contractor who is being pushed to install flooring too early and against manufacturers’ installation guidelines the word 'no' is your only trusted friend.

When it is known that sub-floor flatness, moisture levels, ambient relative humidity, temperature etc. are not at recommended levels and yet the building owner and/or General contractor are insisting you start the installation against your better judgement, get it in writing! If you don't have clear written instructions from the Building owner to proceed then you won't fare well in court should you be sued.

Our advice is as Follows:

1. Say 'no' and wait for job site conditions to meet manufacturers’ recommendations before proceeding.

If 'no' is not an option then:

Write a letter to the Building owner and General contractor stating why you recommend delaying the installation and also stating that proceeding will void the product and installation warranty. do not proceed with installation until you are in receipt of written instructions from the Building owner that states they fully understand the risks and wish to proceed against manufactures’ specifications with no product warranty in place.

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High Fly Ash content concrete - problem or not?

5/13/2015

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If you talk to enough people on the subject of site preparation and flooring issues eventually the question of fly ash concrete and bond failure will crop up. I’ve heard the question from all corners of the industry and there are few definitive answers.

As a result, many commercial flooring contractors are not warrantying their installations over such concrete. Instead, they add a disclaimer in their terms of contract stating that no installation warranty is offered over substrates that contain a greater than 20% fly ash content. Yes, the flooring product warranty will be in place but that’s no good if the adhesive fails.

SO WHAT’S THE PROBLEM?
1. The general consensus is that concrete, with a high fly ash content, results in a denser, less porous product, which in turn interferes with the flooring adhesive and/or leveling compound’s ability to bond. Hard trowelling of the concrete surface to a super smooth finish exacerbates the problem.

2. Collectively, manufacturers have not come out with a clear position on the subject. Is there a bonding problem? If there is, is it slab density related or some other ingredient in the concrete effecting bond? Moisture testing? Should Calcium Chloride (MVER) tests be recommended over this type of concrete? Answer, not sure... many manufacturers call for both RH Probe and Calcium Chloride tests to be taken simultaneously.

WHY IS FLY ASH USED?
Fly ash as an additive in concrete has been around for a long time and will continue to be used for a number of reasons: 1. It helps produce a stronger, more durable concrete product that is less permeable.
2. It aids in the reduction of efflorescence, a white chalky substance that develops on concrete surfaces.
3. It’s use in concrete is LEED driven because:

It reduces the energy intensive use of Portland Cement.
Fly ash is a by-product of burning coal and its use in concrete is one way to use this waste product up.

The reality is that fly ash as an ingredient in concrete will likely increase over time as LEED projects continue to grow in number. So what do you do when faced with an instal- lation over this type of substrate?

As the flooring contractor you should understand the concrete surface you are installing over before proceeding. Ask questions about the concrete mix.
Consult the adhesive / leveler manufacturer before you proceed. Fully understand the limitations of adhesive or leveler that is expected to bond to the concrete surface.
Understand your options regarding possible product upgrades that work better with concrete of this type.
Communicate in writing with the general contractor and building owner regarding voided warranties before you proceed because the industry standard states ‘Installation implies acceptance of conditions’.

   5. Shot blast or scarify the concrete surface to increase             mechanical bond. Concrete specifications should call             for a broom or textured finish of the slab. This work is         the responsibility of the general contractor.
    6. Take a bond (or pull) test before proceeding.                     Document the test by video recording it.
    7. If you have a choice then choose the RH In-Situ probe        moisture test (ASTM F-2170) over the Anhydrous                 Calcium Chloride (MVER) test (ASTM F-1869). Moisture         Vapor Emission Rates (MVER) in fly ash concrete are             reduced because the concrete product is denser. This         increases the risk that an acceptable MVER will be             recorded at the surface while excess moisture is still             present deeper in the slab. When an MVER meets the         manufacturer’s warranty requirements yet fails to                 reveal the true moisture content of the concrete at             deeper levels, the floor installation will be given the             go-ahead risking problems later on. Note that moisture         testing is the responsibility of the general contractor.

For clarity on this issue, the industry requires manufacturers to lead the way and replace opinion with scientific, test-based fact. With this done the end user will stand a better chance of receiving their new floor with product and installation warranties intact.

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The Moisture Monster In Our Industry. Part 3.

5/7/2015

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3. Substrate Testing

Substrate testing is often pushed onto the flooring contractor who then fails to take the tests according industry standards. Taking tests according to industry standard (ASTM), in a commercial setting, can be a complicated and expensive process.

National standards call for 3 tests for the first 1000 sqft of installation area and 1 test for every 1000 sqft thereafter, with strict rules that govern test placement and test area preparation.

The risks for the flooring contractor are obvious:
1. He cannot protect against multiple tests being spoiled on site by other trades disturbing (spoiling) the tests.
2. If the tests fail, who will pay for the next round?

Re-testing costs quickly add up, as does the pressure to take short cuts. The risk for the building owner is also obvious… no assurance that moisture tests will be taken properly unless a third party testing agency is used.

The NFCA Floor Covering Reference Manual states:

Moisture and alkalinity tests shall be conducted by an independent third party testing agency using testing methods and devices in accordance with NFCA requirements and the floor covering manufacturer's recommendations. In multiple story buildings each floor level shall be tested. All test locations shall be marked on As-Built Drawings.

It shall be the responsibility of the General Contractor or Building Owner to provide and pay for such testing in a timely manner.

What can be done to address these issues?
a.    Raise awareness of how sensitive many flooring products are to small amounts of moisture.
b.    Understand how long it takes concrete to become dry enough to receive flooring.
c.     Create acceptable site conditions early enough so that substrates have a chance to dry.

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The Customer Isn't Always Right!

High Fly Ash content concrete - problem or not?

The Moisture Monster In Our Industry. Part 3.

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