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engineered wood laminate flooring

engineered wood laminate flooring

engineered wood laminate flooring

(OP)
I am investigationg a recently installed engineered wood laminate flooring in a 30 foot x 90 foot room, on top of the slab-on-grade. The woood laminate has buckled in a few locations. The slab on grade itself has been in place for 45 years. The wood lamiante flooring was installed in about February and the buckling was noticed about 2 weeks ago. Location is toronto Canada. The laminate wood is not adhered to the slab. I suppose if the wood absorbs moisture from any source, it will expand, and if installed tight with no expansion space, it will buckle when force > Euler buckling load. Could the air conditioning be the cause, in that it increases the relative humidity (although it decreases the absolute humidity) when the air is cooled?

Anyone had any experience with this type of wood, its engineering properties and behavious, and what most probably is the cause of the buckling?

RE: engineered wood laminate flooring

Were the laminate manufacturer's suggested practices followed?

E.g. is there a foam underlayment or other barrier between the laminate backing and the concrete?

Mike Halloran
Pembroke Pines, FL, USA

RE: engineered wood laminate flooring

Floating flooring has to have an underlayment as Mike said, and it also has to have gaps at the edges. It is standard practice to conceal this gap with a molding.

RE: engineered wood laminate flooring

ajk1....as others have noted, probably restraint of expansion. If the material has a wood veneer facing, you would likely see "cupping" if the moisture content were high. If truly a laminate surface, you won't likely see that.

Yes, the AC can be a culprit. If the flooring created a "barrier" on top of the concrete or even a change in the thermal gradient of the floor, then the ambient moisture within the concrete could condense at the bottom of the flooring, causing it to expand.

RE: engineered wood laminate flooring

(OP)
Thank you all very much for these very useful comments. I will follow up and see if I can find the answers to these points. I did not specify the flooring or have anything to do with its installation, but I have been asked to investigate and recommend what to do now. I may have some follow up questions.

I was going to carry our an ASTM D4263 test to check for moisture permeation from below the concrete slab. This may tell me if the source of the mositure is from below the slab or from the ambient air in the room. The 6" slab on grade is very old (45 years) but there was a flood in the building last November when a buried water main broke, and perhaps it takes a long time for the soil below the slab to dry out, although the insurer's contractor brought in large fan heaters and ran them for several weeks to dry out the building right after the flood.


Ther original drawings for the building in 1966 specified a polyethylene sheet under the concrete slab, so this may act as a vapour barrier yo some extent if it was not ripped during the original construction.

On top of the concrete slab was placed a "Granwood" flooring in 1966 in the original constrcution. That is in excellent condition. The new lamianted wood floor was placed on top of the Granwood in February 2012. There is a relatively small part of the floor where there was no Granwood; here a plywood layer was installed just before they placed the new laminated wood floor. This is reportedly one of the worst areas for the buckling, but I have not yet seen it...am going there to see late this morning.

RE: engineered wood laminate flooring

ajk1....if there was flooding, there is likely a lot of interstitial water remaining in the concrete. Generally, unless saturated and no vapor barrier, the soil is not the issue with respect to upward vapor migration/condensation.

RE: engineered wood laminate flooring

(OP)
I am told that the wood laminate flooring has an underlayment and that an expasnion space was provided at the walls. I am headed there this morning to see it.

Any suggestions on:

a) what investgation I should carry out and
b) what remedial measures might be appropriate (this may depend in reuslts of any investiagtion)
c) do you think that it will have to be a matter of replacing any buckled boards when they occur?

RE: engineered wood laminate flooring

Because it was installed in February (low temp and humidity) and then buckled in June leads me to believe that they didn't allow for proper expansion.

But, like others have said, it's either a moisture issues or an expansion issues. Check for both and see what you can see. You can then move on to remedial measures.

As for replacing boards, that depends on the board and the client. I assume that these boards are tongue and groove. Is it easy to pull out large sections of boards and put in new ones or are they going to have to cut some out? If you have to cut them then a lot of flooring people will just tell you to rip it out and start again.

Maine EIT, Civil/Structural. Going to take the 1st part of the 16-hour SE test in October, wish me luck!

RE: engineered wood laminate flooring

Did the installer let the new flooring sit in the building for a couple weeks before they installed it?

Richard A. Cornelius, P.E.
WWW.amlinereast.com

RE: engineered wood laminate flooring

(OP)
In my inspection this morning, I found that they in fact did not leave a gap between the end of the flooring boards and the wall, or at best it was only 1 or 2 mm gap. This is much less than the manufacturer's literature which says the gap should be 15 mm. They have now removed all the baseboards and are correcting this by cutting a piece off each of the floor boards!

The laminated flooring is comprised of :
- an aluminum oxide surface printed on high density finreboard (HDF)
- HDF
- stabilizing layer on the bottom
- locking assembly system between boards

Looking at the end when I break a board in half, it looks really flaky. Anyone had any exerience with this stuff?

I am going to weight it, submerge it for 12 hours, then weigh it to see what percentage moisture it picks up.

I can also take a piece that was lying in the room on site and weigh it, then microwave dry it, the weigh it again to see what its moisture content is.

Do you think these might be useful tests?

RE: engineered wood laminate flooring

ajk1...yes, I've seen this same type of board. I have experienced it buckling from both lack of spacing and moisture. It is highly susceptible to moisture gain.

Don't use a microwave for the moisture content. Use a drying oven if available or your oven at home on low temperature (preferably below 150F). Hopefully your scale is accurate, with a resolution at least to 0.1g. The equilibrium moisture content of the fiberboard part of this material is fairly low, but not zero.

RE: engineered wood laminate flooring

(OP)
Ron - thanks for the advice. Any suggestion as to how long I should dry it in the oven? And how long I should leave ot soak to determine its absorption?

RE: engineered wood laminate flooring

(OP)
My electronic digital scale is calibated in gramd,not 0.1 grams, but I have specimens that weigh 350 grams so that should I think be ok. I have smaller speciemns tsat weigh 8 grams but based on what you say, I think I should not use them in the test.

Can you help me understand the equilibrium moisture (EMC) content? Does it depend on the RH and temperature of the ambient air?

If the EMC is say 5%, and the actual mositure content of the specimen taken from the floor is found to be say 10%, what is the practical meaning of that? Does it mean that the speciemn is absorbing moisture from the surroundings and will continue to do so ubtil the surroundings are changed?

RE: engineered wood laminate flooring

The quality of these floating floors varies a lot. Generally, you pay for what you get. My neighbor had some cheap flooring which was ruined when his dog peed on it.

RE: engineered wood laminate flooring

(OP)
Thanks How To Engineer- The EMC moisture content table is aklso in The Canaf=dain Wood Council Handbook, which I had read prior to your email, but what you sent includes some worked examples which are always useful. Thank you.

RE: engineered wood laminate flooring

I am a little perplexed. Laminate flooring using a HDF core is not a high end product, and if the installer did not install per the manufacturer's recommendations and there is no excess moisture coming from the slab for some reason, then I don't follow why a structural engineer is investigating this. Laminate flooring does not really require any acclimation time before install because the HDF core is a stable product so long as you do not soak it. HDF is used because it is cheap, easily machined and is about the flattest products you can find. There are literally hundreds of these discussions on the fine homebuilding site, woodweb, and examples of poor installations can be found in Charles Peterson's hardwood flooring book. Charles is an engineer and is very knowledgeable when it comes to this. I build Medallions and engineered flooring (hobby) and have done tests before fabricating in my vacuum press. I do not use either MDF or HDF in my work because if moisture is ever a problem it is difficult to salvage.

This seems like a case where you get what you pay for. Cheap product and installers = problems.

RE: engineered wood laminate flooring

(OP)
Thank you Brad805 for this information. A structural engineer (me) is investigating because this is a place of worship and I am a member there and was asked what should be done now. The actions and principles are similar to the effects that structural engineers deal with daily, whether they are designing wood or concrete and must consider the effects of shrinkage and expansion, so it is not totally illogical to have a structural engineer involved. Of course it would likely be better to have someone who has a lot of experience with laminated flooring but we don't have such. The information that you have provided is interesting. Thank you again.

Are you aware of buckling having been caused by the air conditioing? The buckliong occurred on a weekend when the room was full of people and the air conditioning was on that week. The air conditioing (and the people) increases the RH because cold air can hold less moisture than warm air. This is what mechanocal engineers tell me is the case unless slecial demudifying provisions are built into the system, which is not the case in our building. Others to whom I have spoken attibute the most likely casue to the air conditioing and the lack if any expansion space at the end of the flooring boards where they met the wall.

The manufacturer's printed instructions seem to me almost impossible to meet, in that they require the RH in the room to be betwen 45% and 55% when installing the flooring...can be done, but would require special controls on the environment. And there are other stringent requirements that are required to be met when installing.


If this had been my project, I would have retained an inspection and tsting company to carry out site review during installation to verify, at least on a random sampling basis, that the work was being carried out in general accordance with the manufacturer's specifications. I alos reoutinely speciy that the manufacturer's representative visit the site at least once at the start of the work, to verify that the cntractor understands what is to be done to neet the manufacturer's specification.

RE: engineered wood laminate flooring

(OP)
Another thought: Does laminated flooring with HDF core meet Code fire resistance and flame spread rating requirements for assembly occupancy?

RE: engineered wood laminate flooring

I did not see where you mentioned expansion joints. I have installed many lam floors and all require expansion joints at least every 30'

RE: engineered wood laminate flooring

ajk1...in general, you dry the sample until the weight becomes constant...usually about 24 hours for most materials.

HDF will absorb moisture, so in that context, it is no more stable than any other wood product. Further, it is usually anisotropic and will swell in thickness to a greater percentage than its length. Saturation is not required for its dimensions to change.

The material likely has a low fire rating, but that can be checked with the manufacturer's data. It is a combustible material.

As for a structural engineer investigating a materials problem...as ajk1 noted, we do it routinely. Engineering principles apply to many things. Wood can be a highly variable material so structural engineers are obliged to know the variations in properties and their installed environment affectations. Who better than a structural engineer to investigate essentially any physical aspect or material in a building construction application? (with the obvious exclusion of MEP issues)!

RE: engineered wood laminate flooring

I applaud the effort given this is your church and that makes your interest clearer to me. The issue I would have investigating such a problem if I were not somehow attached to the facility is that flooring is probably <$5k (plus maybe $3k for install). Doing a lot of testing one could quickly rack up the replacement value in fees. If it were an engineered floor like Mirage or Kahrs, then its values would be 5 times or more and such an investigation would be more feasible.

Another concern with investigating such a problem like so many of us like to do is this is not a complex problem. It absorbed some moisture, had nowhere to expand, so it buckled. The intent of the underlay is to try to isolate it from slab moisture, and create a "floating floor" that is free to expand and contract. This product is a lot more stable than hardwood so long as it is not exposed to significant moisture changes. I am not aware of the RH fluctuations in Ontario, so you will have to determine if their is need for a extra HVAC items to help stabilize the humidity in that area.

If the install was done correct except for the expansion joints, and you do not have some odd subgrade problem (missing moisture barrier or water table issue) I suggest you cut out an expansion joint and move on with life. I have a German tracksaw that I could cut that out perfectly straight in a very short period of time. Yes, you will need a trim detail to cover the joint. Again, not complicated and standard stuff for a finish carpenter. A few phone calls to a reputable local supplier not related to the project and I bet you will come to a reasonable solution if you want more advice. I have done that and one can tell if they know their stuff by asking questions and listening to the answers. A supplier that deals in hardwood floor re-finishing products might be a good place to start. The owner of the company where I buy my Bona re-finishing products from has always been very helpful.

To determine the fire rating requirements will need to consider the overall size of the occupancy, sprinklers, firewalls (if any), usage and other Part 3 items in the Ontario Building Code. Usually the Architect (or their code consultant) looks after that. If this is a simple reno without such a professional, then you may find the rating requirement in the original drawings if you have them. Having worked at various churches I know they are not usually flush with funds (except some Catholic Churches). Since they selected a laminated floor I am fairly confident your congregation is one of those without extra funds. You may want to leave this alone unless there is someone that can step up and write the cheque to replace it with something that meets the requirements if found to be more stringent.

That was not a great product for this space. I am assuming this is a multi-use area where they use it for a lot of different gatherings. That wear surface is far too thin, and when they move tables and chairs it will scratch. Engineered flooring uses a 5mm wear surface, but this is just a veneer (1/42" +-). I bet in two years they will consider replacing it because it will look awful if this is indeed a high use area.

Good luck and kudos for the effort.

RE: engineered wood laminate flooring

The air conditioning had nothing to do with it.

Toronto in winter is very, very dry.
The floor was installed with zero expansion clearance at the ends.
When the humidity went up with the temperature, the floor expanded.
.. and buckled, as it was forced to do.

I'd try to shorten just the endmost boards, e.g. by cutting next to the baseboards with a vibrating saw, and give the floor an opportunity to stabilize itself.

Mike Halloran
Pembroke Pines, FL, USA

RE: engineered wood laminate flooring

(OP)
The room is about 30 ft x 80 ft and the cost of the floor is a heck of a lot more than 5K, although I don't know exactly the cost becaseu a member of the congregation (a general contractor) paid for it. He jsut did his own thing, and did not use an architect.

They now have in fact cut off a piece of the flooring all along the perimeter of the room, to allow for expansion, but they have still got it fitting tight to the door frame.

How can the gap be concealed at the door frame, since they can't place a quarter-round or baseboard at the door frame?

Also, how can expansion be accommodated at the door threshold? Are there custom thresholds that can be used to accommodate the expansion?

I have found that the manufacturer also requires expansion joints at about 8 m (26 ft) centres within the floor area, so we are going to have to get these put in too.

Yes it is a multi-use room, but so far I do not see any scratching of the surface, and it has been in place a couple of months.

I am no expert on smoke developed and falme spread, but my review of the Ontarion Building Code seems to indicate that there are no requirements for floor surfaces except for corridors and the like in high rise buildings.

Thanks for your help. I look forward to hearing your comments on the above.

RE: engineered wood laminate flooring

You can just use a colored acrylic sealant at the door architraves. And yes, there are thresholds, same as the expansion joint covers, but these are generally installed as you go. They look like an "H", with a convex top side.

RE: engineered wood laminate flooring

(OP)
Ron - thanks for your comments, especially about the appropriateness of a structural engineer investigating this problem. Very well put. I have been 347 garm soaking a specimen of the material for 4 days now and taking it out of the water and surface drying and weighing every 24 hours. It is still continuing to absorb water. When I plot the curve of weight vs elapsed time, there is no sign of it becoming asymptotic to a final weight. I am really curious as to how long it will continue to absorb water. Unfortunately I did not measure its length change ... maybe I can do this when I let it dry. However there is little or no visible distortion in any direction, which I think is a good thing. The manufacturer has only European fire test data, so I don't know how that correlates with North American standards, but anyway the Ontario Building Code does not seem to require flame spread rating aor smoke developed classification for floors (except if covered by carpet or in high rise buildings) and the European data does seem to indicate that it does have adequate properties.

MikeHalloran - I just watched the manufacturer's video and they showed that the door frames are to be cut short of the floor so that the wood lamimate can expand under the door. I had thought of using a sealant, as suggested, but it is not going to look that great...but we may end up doing that. I suspect bearing against the door frame may have been a big part of the cause since the eruptions were all approxinmately in line with it although one of the eruptions was well away from it (but still in line with it).

I have found that not only does the manufacturer have explicit printed instructions about what to do about expasnion joints, but also has a good video covering all these points. It also says that all furniture should have felt pads attached to the legs. I tried doing that to my home furniture on the hardwood floors a few years ago and the felt pads eventually all came off.

RE: engineered wood laminate flooring

Must have been a crappy adhesive. My family has nice hardwood floors and used the felt pads you can buy at any hardware store and hasn't had a problem with the felt coming loose even with our heavy wood chairs.

Maine EIT, Civil/Structural. Going to take the 1st part of the 16-hour SE test in October, wish me luck!

RE: engineered wood laminate flooring

ajk1,
Just soaking a piece of the flooring doesn't prove much. The performance of the assembly is what matters, and I believe the expansion due to moisture absorption is greater perpendicular to the boards than parallel.

The floating floor can only be installed under the architraves before the architraves are in place.


RE: engineered wood laminate flooring

(OP)
The manufacturer's video shows a piece being cut from the bottom of existing door frames to allow for expasnion of the new flooring.

The video (and printed instructions) show expansion joints at 8 m x 10 m within the floor area which was not done in the installation in our case. Should we make them go back and put those in, or can we assume that since they cut a new expansion space all around the perimeter of the roo, that things will be ok without the expansion joints within the floor area, since the perimeter expansion joints were cut in the more humid summer season (the original installation was back in February)?

RE: engineered wood laminate flooring

I don't think "make them go back and.." is going to fly, since some large portion, perhaps all, of labor and materials was donated by a church member. There are no adversaries to engage.

Now, having cut a relief space all around, I would hold a dance or other dynamic crowd activity on the floor, to give it a chance to level itself out.

Before said event, I would leave the a/c on 24/7 for a few weeks to try and shrink things a bit.

The typical church custom of only using the a/c when the space is occupied is probably not helping this situation.

I'd only attempt retrofitting expansion joints as a last resort, if nothing else works, and if the community is prepared to replace the entire floor anyway.

... which brings up another thought. If the flooring is of the type that snaps together _and_ can be unsnapped without major damage, it might be possible to pull it up and relay it, with expansion joints, rather than trying to cut the joints in to the assembled floor.

Mike Halloran
Pembroke Pines, FL, USA

RE: engineered wood laminate flooring

I was assuming the flooring is the "snap together" type when I made the comment about getting the floor to go under the architraves. Having laid a few myself, you can't do it, as you have to angle the boards to engage the joints.

RE: engineered wood laminate flooring

(OP)
yes hokie, it is the snap together type. Interesting point you make.

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