engineered wood laminate flooring

[ajk1]

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?

 

[Ron]

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)!

 

[Brad805]

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.

 

[MikeHalloran]

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

 

[ajk1]

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.

 

[hokie66]

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.

 

[ajk1]

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.

 

[TehMightyEngineer]

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!

 

[hokie66]

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.

 

[ajk1]

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)?

 

[MikeHalloran]

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

 

[hokie66]

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.

 

[ajk1]

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