Laminate Floor Flexing

bigdogg1

Well-Known Member
In between watching threads on 300K for 100K and Best Thread of Year (and anything from @Stizzla), I decided to do a complete kitchen reno o_O. It is actually going well with new subfloor, underlayment and electrical moved.

I cut back the pre-existing laminate floor that bordered the kitchen floor by 1' to increase the footprint of the kitchen. Prior to doing this, the laminate lay flat and has been stable for the last decade. It was still 'normal' when the transition strips were removed between the laminate and the kitchen.

However, once the 1' was cut back (10' on one edge and 6' on the perpendicular edge), the longer edge has become springy ie it now has a bounce of approximately 3mm to it. There is appropriate relief around the edges and it only is on the longer side (which runs perpendicular to how the laminate lays).

I checked the support underneath and all appear to be cupped properly.

I would like to remove this bounce prior to installing the kitchen floor and new transition strips. I am very close to taking my air gun and setting in a strip of 2" staples along the edge to tuck it down and cover the staples with the transition strip. Not fine carpentry but it was not an issue prior to cutting back so I cannot understand why it has this small bounce.

Does anyone have any other ideas? Thanks!
 
If you would like to pm me I can give you my # and we can text because pics are easier to send
 
Try construction adhesive, Bulldog etc, then place a board with weight on it to keep it down and in place for 24hrs. Should not move again in your life time. I am not a laminate guy but I have been a tile contractor for over 30yrs. Just a suggestion. Cheers
 
I don’t recommend using staples or construction adhesive. It prevents the floor from floating and can cause other issues with seasonal changes. If you have the ability to pull a board out, via cutting out or using a bulldog tool, grab some bostiks best flooring adhesive in a cartridge. It cures stretchy and allows the floor to still move a bit. Better yet, if you can resch the “low spot” from the open end, shove some thin underlay or flat cardboard pieces to shim it up and give it some support.
 
From the instructions I recall when we were putting some in and further to Stizzla's comment about the floor needing to float. I understand that there should be gaps at the edge/join points so that the floor can expand and contract with temperature etc. When you cut it back and changed the edge/join did you leave room for this? If not perhaps that is what is causing it to lift. If it can't move flat sideways all it can do is push up when it expands. Not an expert like Stizzia but it does seem logical. Also remember something about a max width for some floating laminate floors without an expansion joint. Apparently if it is too wide the expansion space on the edges may be insufficient. This is just my memory from ten years ago, so hopefully I am not full of crap.
 
Last edited:
From the instructions I recall when we were putting some in and further to Stizzla's comment about the floor needing to float. I understand that there should be gaps at the edge/join points so that the floor can expand and contract with temperature etc. When you cut it back and changed the edge/join did you leave room for this? If not perhaps that is what is causing it to lift. If it can't move flat sideways all it can do is push up when it expands. Not an expert like Stizzia but it does seem logical. Also remember something about a max width for some floating laminate floors without an expansion joint. Apparently if it is too wide the expansion space on the edges may be insufficient. This is just my memory from ten years ago, so hopefully I am not full of crap.
You’re on point there Rockfish! I believe he mentioned that he did have expansion room everywhere. The max distance is also correct, but it’s usually pretty generous, like 50’. I’m wondering if there is a gradual slope in the subfloor and the weight of the additional flooring before was enough to hold it all down and now it’s lipping up over the peak.
Definitely throw a straight edge (preferably 8’ or longer)and see if there’s a drop off somewhere.

The most common causes for a spongy floor are:
-Uneven subfloor
-moisture level changes
-lack of expansion (this can include cabinets being installed on top of a floating floor.)
 
You’re on point there Rockfish! I believe he mentioned that he did have expansion room everywhere. The max distance is also correct, but it’s usually pretty generous, like 50’. I’m wondering if there is a gradual slope in the subfloor and the weight of the additional flooring before was enough to hold it all down and now it’s lipping up over the peak.
Definitely throw a straight edge (preferably 8’ or longer)and see if there’s a drop off somewhere.

The most common causes for a spongy floor are:
-Uneven subfloor
-moisture level changes
-lack of expansion (this can include cabinets being installed on top of a floating floor.)
Thanks everyone - I like the burn it down approach from RC but since I am a bit in debt for my new to us Striper :):) :), that flooring reno will come later. After a few pops last night, I went back to my crawl space and it turns out that the flex point is EXACTLY where there are crown up and crown down floor joists so I am sure that that is the cause.

I have a fine piece of transition strip in mind that I will likely countersink some screws through to the subfloor and fill/stain to match etc. I tried a mock piece last night and it took the flex out nicely.

Then, in the future, when I follow RC's Burn plan, I can pop the screws and move forward.

(On a side note, the laminate flooring we installed has been bullet proof actually. It has survived 10 years of 3 dogs averaging 80 pounds and a more significant beating from daily ministick battles/tournaments!)

Thanks again!
 
Back
Top