Why Is My LVP Floor Buckling in Austin Summer Heat?

You installed luxury vinyl plank flooring and it looked great. Then summer hit. Now there are ridges, humps, or gaps where the planks used to lie flat. This is one of the most common flooring calls we get in Austin from June through September, and the fix is almost always straightforward once you understand what is actually happening.

The Problem: Thermal Expansion in Central Texas Heat

LVP is made primarily of PVC, which expands and contracts with temperature changes. In most climates this is not an issue. In Austin, where interior temperatures can swing from 68 degrees in winter to 80 degrees or higher in summer, and where direct sunlight through windows can heat a floor surface to 100 degrees or more, the expansion can exceed what the floor's expansion gaps can absorb.

When planks expand and have nowhere to go, they push against each other and buckle upward. This is called thermal buckling, and it is a sign that the floor was either installed without adequate expansion gaps, the expansion gaps were filled in with baseboard or quarter round, or the floor is a lower-quality product with poor dimensional stability.

The Other Cause: Moisture from Below

Austin's clay soil holds moisture, and concrete slabs can transmit that moisture upward through vapor emission. If a moisture barrier was not installed under the LVP, or if the barrier was inadequate, moisture can get trapped under the planks. This causes the planks to cup, bow, or lift at the edges. This is different from thermal buckling but looks similar from above.

A simple calcium chloride test or a relative humidity probe test can tell us whether moisture is the culprit. We do this before any repair work so we are fixing the right problem.

How We Fix It

Step 1: Diagnose the Root Cause

We inspect the floor, check for moisture, and assess the expansion gaps. We also look at the product spec sheet to confirm the manufacturer's temperature and humidity tolerances. This tells us whether we are dealing with a product failure, an installation error, or a site condition issue.

Step 2: Address the Root Cause

If it is a moisture problem, we install or upgrade the moisture barrier before reinstalling the floor. If it is an expansion gap issue, we remove the baseboards or quarter round, allow the floor to contract back to flat, re-cut the expansion gaps, and reinstall the trim with proper clearance. If the product itself is the problem, we discuss replacement options with you.

Step 3: Reinstall Correctly

Proper LVP installation in Austin requires a minimum 3/8-inch expansion gap at all walls, door frames, cabinets, and fixed objects. We also recommend keeping interior temperatures consistent and avoiding prolonged direct sunlight on the floor surface during the hottest months.

Can I Prevent This from Happening Again?

Yes. When we install LVP, we use products rated for Central Texas conditions, maintain proper expansion gaps throughout, install a quality moisture barrier on all slab installations, and brief homeowners on temperature management and UV exposure. We also recommend keeping your HVAC running consistently rather than letting the house get extremely hot when you are away.