Does LVP flooring expand and contract with humidity changes in NB?

LVP does expand and contract, but far less than hardwood or laminate, which is one of its biggest advantages in New Brunswick's Maritime climate. While no flooring material is completely immune to dimensional change, quality SPC-core and WPC-core LVP products offer dramatically better stability through NB's extreme 30 to 50 percent relative humidity swings between winter and summer.

The mechanism is different from wood-based flooring. Hardwood and laminate absorb and release moisture, causing them to physically swell and shrink — this is why solid hardwood floors in NB homes develop visible gaps every winter when indoor humidity drops to 20 to 30 percent, and may cup during humid summer months. LVP, by contrast, responds primarily to temperature changes rather than humidity. Vinyl softens slightly and expands when warm and contracts slightly when cool. This thermal response is generally much smaller in magnitude than the moisture response of wood, but it is not zero — and in NB, it matters.

SPC-core (stone polymer composite) LVP has the best dimensional stability of any LVP type. The rigid limestone-powder core barely responds to temperature changes and is essentially unaffected by humidity. SPC products are the top recommendation for NB homes where temperature fluctuations are significant — think rooms with large south-facing windows that heat up in summer sun, or sunrooms and enclosed porches that swing from warm daytime to cool evening temperatures. WPC-core (wood polymer composite) LVP is slightly more susceptible to thermal expansion due to its foamed core structure, though still vastly superior to hardwood or laminate.

Despite LVP's superior stability, proper expansion gaps are still mandatory in NB. Manufacturers specify 6 to 10mm gaps around all walls, door frames, cabinets, pipes, and fixed objects. Some NB installers are tempted to reduce these gaps because "vinyl doesn't move much" — this is a mistake. In a 20-foot-wide NB living room that experiences a 15 to 20 degree Celsius temperature swing between a cold January night and a sunny July afternoon, even the small per-plank expansion adds up across the room. Without adequate gaps, the accumulated expansion can cause the floor to buckle, tent, or push against baseboards and door frames.

Situations where LVP dimensional movement becomes noticeable in NB include direct sunlight through large windows (surface temperatures can reach 40 degrees Celsius or higher, causing localized expansion), rooms above unheated crawl spaces where floor temperatures fluctuate more dramatically, and installations that bridge heated and unheated zones without proper transition strips. In these scenarios, choosing an SPC-core product and maintaining the manufacturer's specified expansion gaps eliminates virtually all movement-related issues.

Compared to the alternatives in NB's climate, LVP's dimensional stability is a decisive advantage. Solid hardwood requires a whole-home humidifier in winter and dehumidifier in summer to stay within its safe 35 to 55 percent RH range. Standard laminate with an HDF core swells permanently if exposed to moisture. LVP simply handles NB's moisture and temperature extremes with minimal fuss — it is one of the primary reasons LVP has become the fastest-growing flooring category in the province.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• The Garbage Guys Ltd
• RenoMe
• First united design & construction inc.
• FRS Flooring Solutions
• Modern Epoxy Inc