Flooring in Manor, and What Sits Under It

New houses on old prairie

Manor sits east of Austin on the Blackland Prairie — deep, dark, highly expansive clay that farmed well and builds hard.

Almost all of Manor’s housing is recent. ShadowGlen, Presidential Glen, Bell Farms and Stonewater between them represent a very large amount of post-2005 construction on ground that moves substantially with the seasons.

That combination puts two questions in front of every job here, and they are the same two that dominate our Hutto and Pflugerville work.

Question one: is the slab dry yet

Concrete releases moisture for months after it is poured, and clay ground beneath it slows that down rather than helping.

Where a homeowner in a young Manor house wants to replace the builder’s carpet with glued-down plank, the in-slab relative humidity reading decides the job — the adhesive, whether a moisture mitigation coating is needed, and occasionally whether the work should wait.

Probes go in and stay in for the full 72 hours specified by ASTM F2170, because a probe read early reads low and low is the dangerous direction. You get the number in writing, and it is what every adhesive limit and every manufacturer warranty is judged against if a claim is ever made.

Where the reading comes back above the adhesive’s limit, an epoxy barrier goes down first. It is a genuine line item, it is not cheap, and it is the most common omission on a competing quote — because it only becomes visible after somebody runs the test. Skipping it does not remove the moisture; it moves the consequence to about eighteen months out.

Question two: what happens when the ground moves

Through a dry summer the clay under a Manor slab perimeter shrinks and the edges settle. When the rains come it swells back. Over a severe drought cycle the amplitude is substantial.

Post-tension slabs are standard here and they do their job — they keep the slab acting as one stiff plate over soil that will not stay still. But the plate still moves, and what goes on top of it has to accept that.

Under tile, a crack-isolation or uncoupling membrane is the specification rather than an upgrade. Tile is the most rigid thing in the house and a slab crack will telegraph through a bonded field along the grout line nearest a load-bearing wall. The membrane appears as its own line on our estimate.

Floating rigid-core plank has a real advantage here rather than being merely the cheaper option. It is not bonded to the slab, so it rides seasonal movement instead of reporting it. That is why the honest recommendation in Manor is often plank in rooms that were assumed to be tile.

Levelling and timing

A Manor slab that is out of level is out of level because it moved, not because it was placed that way — the opposite of the situation up on the limestone.

Grinding a floor flat at the bottom of a drought cycle produces a floor that is out of true in the other direction when the ground rehydrates. So we ask about foundation history before pricing a levelling job: doors that have started sticking, cracks that appeared this summer, a floor that has changed since you moved in.

Sometimes the right sequence is to deal with the ground first. That is the smaller job for us.

The older core

The blocks around the original town centre predate the subdivisions by a long way, and they sit on the same clay with different construction. Worth a separate look rather than an assumption carried over from the new-build side of town.