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Expansion Joints for Hardwood Install



Do I need expansion joints in the center of my hardwood installation?

Bob,
I got your name from the LL chat help line.

I purchased 1400 sf of 5" wide (3/4" thick) Brazilian Koa from the Tulsa LL store to install over a wood sub floor.  My question is on expansion room.  I have a master bedroom, living room and dining rooms that are all basically going to be one big area separated by a couple of double wide door ways.  Other than at the walls (where I plan to leave 1/2 to 3/4 gap) do I need expansion joints (like the "washer method" described on your website) or some thing more or nothing at all???

Thanks Carl

 

Thank you for your email to Lumber Liquidator's Technical & Installation.

 

The perimeter expansion you stated (1/2"-3/4") should do just fine.

 

There are several factors experienced installer's may consider if "dime rows" or center expansions are necessary to place into the flooring. Some are; moisture levels or the lack thereof in a particular region of the country, moisture levels in the product at time of installation and total Sq ft area of installation

 

When installing hardwood in larger Sq ft areas and in very dry regions of the country many installers often take into account how boards tend to expand during the wetter seasons. As the air moisture or humidity climbs over 55%, boards will normally want to expand or grow more-so across the face or short side than the board ends or length. Board movement, growth or expansion is both individual and accumulative across the surface of the flooring. For example; if humidity levels over 55% are sustained, each board may gain the thickness of- 3 sheets of paper- in moisture. Imagine the negative effect of side-to-side board movement when multiplied by the total number of installed boards in the flooring! Under these circumstances, larger Sq ft areas can benefit from the added built-in expansion allowing for center flex or relief preventing board edge cupping/crushing.

 

 As mentioned, when hardwood is installed in larger room areas it may necessitate "dime rows", center expansion or breaks. This procedure is often used when installing maple hardwood "Sport floors" or Arenas. Due to enormous Sq ft areas of these type floors and daily humidity fluctuations, board movement is sure to happen and should be expected. Installers normally discuss or plan with the customer where and how often these breaks will be used. Brakes are usually placed at every 3', 6', or 10' row intervals, often not a visual issue as the floor settles in. If expansion breaks were not provided during these installations serious job failure or product damage could result.       

 

Will center expansion be needed in your floor project?

As noted, because of the many variables involved it is recommended to consult with your local hardwood installer. They can see all the factors involved and make recommendations for the best installation possible.

 

The Lumber Liquidators installation department has well over 100yrs of installation experience. Although we are not an installation company, we are here to provide installation support for you and your installers with product knowledge and documentation. Our observations are to be viewed as helpful, not intended to take the place of local experienced installers that best "see" the true conditions.

 

We wish you a successful installation; please contact us if you need additional information. Enjoy your flooring!

 

 

 

Technical and Installation