# How much does laminate flooring expand or contract



## peter1

I'm aware of the 48-hour acclimation and 1/4" gap requirement of laminate flooring. But how much does it really expand or contract? And does it expand/contract uniformly in all directions?

Something is puzzling me (if laminate is so sensitive to the environment)...say if I install it in the summer and leave a 1/4" gap and cover the gap with quarter round, wouldn't it contract in the winter and exposes the gap (unless really big quarter round was used)?

Why not leave no gap during summer install (or any hot/humid day) or leave big gap during winter (or any cold/dry day) install?

Just curious.


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## AtlanticWBConst.

peter1 said:


> I'm aware of the 48-hour acclimation and 1/4" gap requirement of laminate flooring. But how much does it really expand or contract?


This is standard practice for any porous or wood product based flooring material - that is to be installed in a home's interior environment. There is no set rule as to 'how much' a product will acclimate in any particaular 'individual' home. There are many, many factors that affect this. 



peter1 said:


> And does it expand/contract uniformly in all directions?


No. again, there are many, many factors that effect this. Example: You may have an area near a heat source like a heating vent or a stove/fireplace. This may cause a higher rate of contraction in that area. You may have a large area that sits in front of a group of glass that has sun shining directly onto an area of the floor for most of the day = higher contraction in that area, while other areas are never hit by the sun. You may have an area near a radiator = more airborne moist air....etc, etc...



peter1 said:


> Something is puzzling me (if laminate is so sensitive to the environment)...say if I install it in the summer and leave a 1/4" gap and cover the gap with quarter round, wouldn't it contract in the winter and exposes the gap (unless really big quarter round was used)?


Quarter round is not named as such based on it being 1/4" in depth thickness. 
It is for named for it's measurement being 1/4 of a full round. You may purchase quarter round in a variety of depth thicknesses. The most common used size is 3/4" in thickness. 
We actually prefer to use base shoe molding, rather than quarter round for laminate floor installs. So to answer your question, no it will not 'overcontract' leaving the gap visible, when installed with the right size gap and the correct sized quarter round or base shoe (also referred to as 'shoe-base')



peter1 said:


> Why not leave no gap during summer install (or any hot/humid day) or leave big gap during winter (or any cold/dry day) install?


The yearly time period of when your flooring is installed is not the only factor that dictates and governs the expansion gap. 
There are other facters that can effect the way your laminate floor reacts to your home's interior environment. These include the floor level it is installed in (basement, 1st floor, 2nd, 3rd floor), the part of the country you live in, the temperatures that you keep your home in during winter or summer. (Some people keep the thermostat at 63, some at 76- in the winter = dry air fluctuations) Some use central air all summer long, some never use AC at all and keep their windows open all summer....All these points and much more effect the moisture, humidity, etc...in a home's environment.
Thus, always install with the gap to allow space for the floor to float.
Remember that the floor is a 'floating' floor. The whole floor expands and contracts, not just it's edges...


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## peter1

Thank you for the very detailed explanation, much appreciated :thumbup:


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## Floorwizard

no doubt.

that was great!


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## Lahla76

What should be used as a molding along a patio door? 

When my laminate was installed they used a very flimsy piece of wood and nailed half of it into the subfloor and half into the laminate. Needless to say, part of it pulled away from the door frame and the other part stayed tight to the frame. I just installed a quater round but my concern is that with the expanding and contracting of the floor I may have caused an even greater problem i.e. will the floor expand to the 2" finishing nails and buckle?

Thanks for the previous detailed information. Very informative.


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## AtlanticWBConst.

Lahla76 said:


> What should be used as a molding along a patio door?
> 
> When my laminate was installed they used a very flimsy piece of wood and nailed half of it into the subfloor and half into the laminate. Needless to say, part of it pulled away from the door frame and the other part stayed tight to the frame. I just installed a quater round but my concern is that with the expanding and contracting of the floor I may have caused an even greater problem i.e. will the floor expand to the 2" finishing nails and buckle?
> 
> Thanks for the previous detailed information. Very informative.


If I understand you correctly, we have installed 'T' molding made from the same materials or produced by the same floor maunfacturer. It is like a transition strip molding. However, it has a slightly rounded top, like 1/2 a bullnose. Face that side to the door. They should have installed the flooring with enough space to also install a molding there.


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