As below, so above. Resilient flooring, when bonded with an adhesive, follows every contour of a substrate, essentially forming a skin. Joints, cracks, depressions, protrusions, and seemingly insignificant imperfections on a substrate surface may telegraph through and become very obvious after the resilient flooring is installed particularly if the flooring has a high gloss finish or if it is highly polished
Wood, laminate & LVT, floating floors shrink and expand as site conditions (relative humidity and temperature) change through the four season cycle. T-Caps are designed as a finishing detail (for doorways etc.) to cover expansion spaces while allowing floor movement. T-Caps and other overlap transitions are often installed using too much adhesive which bonds the floor covering to the sub-floor preventing this natural movement. This can lead to buckling, squeaking, lifting edges and/or broken locking joints as the floor binds on whatever is blocking it.
Message from the National Floor Covering Association (NFCA) Board of Directors
When everyone agrees that improvement is not only needed but desired, change becomes possible.
For almost 30 years architects and spec writers have had access to the NFCA floor covering reference manual to guide floor-covering installations through the construction process and become part of that improvement. Yet the same issues still exist today:
As of July 27 2016, the NFCA has re-formed with the goal of affecting positive change for our industry.
What would this change look like?
After the first meeting in August, the NFCA’s newly appointed Board of Directors agreed to focus on the following four key areas where the most meaningful improvements could be made.
We look forward to more dialogue with industry professionals and building a community of engaged colleagues with a common purpose. We invite you to visit the NFCA website at www.nfca.ca to learn more. We’re in the beginning stages, so there’s lots of great work to be done.
The need to plan ahead in construction is obvious, and yet flooring contractors run into the same problems over and over again suggesting little to no planning was done to ensure flat, dry concrete is available day one of the installation. Missed deadlines cost construction parties thousands of dollars a day, and yet the issue of concrete readiness continues.
One such example took place early last year on a project which had the NFCA (National Floor Covering Association) floor inspection service specified. The project was a new commercial build in the interior of BC. As per NFCA spec., a pre-installation site meeting was held to review a list of NFCA requirements including among other things, floor flatness, and moisture testing.
As usual, moisture testing requirements were an issue because the GC had not expected to have to provide and pay for third party testing as per NFCA spec. Nor did he think he would be facing a moisture issue, seeing as he’d poured the slab seven months before the flooring was scheduled to be installed.
During the meeting, the floor inspector mentioned that the 8” thick concrete sub-floor would most likely not be dry enough for the planned installation date. The GC dismissed this.
Three weeks before the installation start date, the moisture tests were done (ASTM F-2170 RH In-Situ Probe) and results provided. All tests had failed with an average 94% Relative Humidity instead of the maximum allowed 85%. With these high readings, neither the adhesive manufacturer or the floor covering manufacturer would warranty the product.
The project quickly ground to a halt because the flooring contractor, quite rightly, refused to install over the wet concrete. With the completion date looming, the building owner had to make a decision - either wait for the concrete to dry, buy a moisture barrier or sign a release. After a lot of back and forth the decision was made to sign a release. All parties drew up legal letters agreeing that the building owner was choosing not to buy a moisture barrier and was waiving the warranty.
The floor installation went ahead over wet concrete and was finished on time.
As a sub-trade, saying ‘no’ to your customer is not easy, however if you do find yourself installing against your better judgement and manufacturers installation guidelines, make sure you ‘GET IT IN WRITING’ from the building owner and or General Contractor. It won’t guarantee you protection in court but it will help you defend your position.
Hardwood flooring and in floor, hot water radiant heating systems can work very well together. Just follow these tips..
Maintaining a consistent, normal heat and relative humidity
(average living conditions) before, during and after installation will ensure minimal shrinkage, expansion and stress of the hardwood floor.
Only deliver the wood flooring to site after the site has been confirmed dry and the temperature is at approximately 20c.
Concrete subfloors: Residual moisture in the concrete substrate exceeding a 3 lb MVER (Moisture Vapor Emission Rate) has the potential to cause swelling, buckling and shrinkage of the flooring product. Use the wood flooring manufacturers recommended moisture test or the NFCA approved Anhydrous Calcium Chloride test method and perform this test in accordance with ASTM F -1869.
Plywood subfloors: For plywood substrates confirm that the plywood is dry all the way through its thickness at 12%. There should be no more than a 4% spread in moisture content between the subfloor and the hardwood flooring. Think about what is below. If there is excess moisture present it will migrate through the plywood reaching the hardwood in a matter of days causing expansion problems.
There are no guarantees against gaps between the hardwood pieces, so avoid choosing light woods such as natural maple because any gaps will show up black and in strong contrast to the lighter wood surface.
Note that most flooring issues are caused by improper site conditions, excess moisture levels in the subfloor, acclimation of the hardwood flooring to wrong site conditions and inadequate subfloor preparation.
The following ‘Acceptable Conditions’ must be confirmed prior to shipping wood flooring to site.
• The home must be at lock up stage and the interior protected from outside conditions – all outside windows and doors must be installed.
• All wet trades such as tile and dry wall mudding should be finished.
• Wall paint: If water based paint is to be used, apply undercoats prior to flooring delivery. Final coat and touch ups can be applied after installation.
• If a cementitious underlayment is used to level the subfloor it should NOT be poured while the flooring is on site. Once poured, confirm the cement underlayment is dry before delivering wood flooring to site.
Special note: The subfloor must be flattened to NFCA standards which are:
Straight Edge Method: 1/8” + or – over 10’ in 360 degrees.
• The heating systems thermostat dial must be installed and operating so that gradual (5 degrees per day) temperature adjustments can be made as necessary.
• The indoor ambient temperature should be set at approximately 18 - 20c.
• Floor temperature should not be allowed to exceed 26c or dip below 15c.
• Ambient relative humidity should be maintained between 35% and 55%
• With these conditions established, the flooring should be delivered and left in the installation area for a minimum of 4 days with any plastic wrapping around the packs cut open. For solid wood flooring an acclimation period of 7 days is recommended. Always check individual manufacturers instructions and do as they instruct.
• Flooring should be stacked in a log cabin fashion on the heated floor to facilitate air circulation.
Floor protection: Cover the floor with builders paper, tape the paper at the seems (not to the floor). Do not cover with thick layers of protection such as drywall or plywood as this will insulate risking overheating of the hardwood flooring.
Lastly, Protect your warranty and yourself by taking photos of the acclimating wood, and a thermometer/ hygrometer registering the date and correct site conditions. Email the pictures to your self so you have a permanent record.
Time after time we are called out to inspect newly installed hardwood floors that are squeaking and or not laying down flat. Time after time our inspectors deliver the same conclusion 'The specified expansion gap did not meet the manufacturers requirements'.
Before we look at some reasons for this it is important to understand that in order to guarantee success of a wood floor it must be allowed expand and contract naturally through the four season cycle. Why, because wood is hygroscopic, which means it will absorb, hold and then release moisture over time, depending on moisture levels in the surrounding environment. Changing relative humidity (RH) and temperatures levels influence the shape and size of wood flooring on a daily, even hourly basis. Without the ability to expand and contract freely, the risk is that your wood flooring will bind against an obstruction causing squeaking, lifting and joint stress.
Wood flooring products are dried in a kiln at the factory, warehoused, shipped across deserts and oceans by truck or in steel containers in the heat of the summer and cold of the winter, eventually arriving at the place of installation. This all takes place with the wood flooring moisture content fluctuating between 6 - 9%. At the final destination, the home, installation temperature should be approximately 20c (70f) and the RH between 35 - 55%. Once acclimated to correct site conditions, installation can begin. These temperature and relative humidity conditions should be maintained if movement is to be minimized after installation. If these levels don't change the wood flooring won't change. But as we all know, temperature and RH levels do change, a lot, and so care should be taken when planning delivery times and recording moisture and humidity levels on site.
This is common knowledge for hardwood installers and yet we still see a high incidence of problems related to inadequate expansion gaps.
Here are a few examples of problems we see:
Do not deliver the wood flooring to site until these or manufacturers recommended site conditions exist.
Good luck with your next installation!
Squeaks and wood are par the course in the hardwood floor industry especially in older homes.
Occasionally I have come across squeaking floors that have been installed in new or renovated homes. If your hardwood is squeaking after installation, contact your supplier, installer or dealer and ask them to inspect the floor. They will be able to give you a reason as to why and offer a solution. If you are on your own having installed the floor yourself then here are some methods we have used to stop squeaks depending on your scenario:
In a home renovation always have someone re-screw the subfloor plywood before you begin the hardwood installation. It's inexpensive to do and doesn't take long - 2 inch flooring screws work great.
In 90% of the cases, in my experience, squeaks come from the substrate not the hardwood. Unless you are prepared to expose the subfloor by removing flooring pieces, you'll be lucky to eliminate the squeaks. Joists, plywood and cross blocking all flex and move and it doesn't take much movement to cause noise. Old staircases are a great example of how old wood subjected to repeated traffic over many years will weaken and begin to squeak. You'll need to rebuild the staircase if you really want the noise to go away.
My advice, in most cases, is to live with the noises and this unique character that your older home came with when you bought it.
One Last Note...
Always purchase wood flooring material from a reputable dealer who has had years of positive experience with the wood flooring brand being purchased. Saving money at an auction or a 'blow out sale' center is a big risk. Such things as bad product milling, incorrect kiln drying and poor storage will cause the flooring to perform badly once installed.
The importance of testing the sub-floor for moisture before your hardwood flooring is delivered to the job site cannot be overstated.
I've seen it time and again where perfectly good flooring is ruined because the homeowner or flooring contractor deliver the wood flooring before ensuring that the installation area is fully dry.
Small amounts of moisture, not detectable by the eye, are enough to cause significant expansion in the new flooring. Later, when the flooring dries out because of normal house heating, it will shrink leaving unsightly gaps between the boards.
Use a moisture meter. Rent one if necessary.
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