Tile Installation & Repair in Chapel Hill, NC

The grout is not the problem

Chapel Hill is wooded in a way most of the Triangle is not, and one consequence people rarely connect to their bathroom is that houses here run damper for longer.

Which brings us to the most common tile call we get in this town: grout that goes black.

It is nearly always treated as a grout problem. It is nearly always a moisture problem.

What the black actually is

Dark discolouration along grout lines, in the sealant at the bottom of a shower, and around the edges of a bath is biological growth. Grout is a porous cement product with a rough surface, which makes it excellent habitat: it holds moisture, it holds soap residue, and in a room that stays humid it never dries out enough to become inhospitable.

Bleaching it removes the colour, not the growth. That is why it comes back so quickly. The organism is in the porous body of the grout, not sitting on the surface.

Regrouting resets it to zero and changes nothing else. New grout in a room that stays damp gets colonised exactly the way the old grout did, on much the same timescale.

Getting the room to dry

This is the part that actually fixes it, and it is unglamorous.

Run the fan for long enough. The single most effective change, and the one nobody makes. A fan that runs while somebody is in the room and stops when they leave has removed almost none of the moisture — the humidity peaks after the shower stops. Fifteen to twenty minutes afterwards is a reasonable target.

A timer switch or a humidity-sensing fan does this automatically and removes the need for anyone to remember.

Check where the fan goes. In older houses this is frequently the problem. A fan that vents into a roof space rather than to outside is moving moisture from one part of the house into another, where it does more harm. A long, flexible, sagging duct run may be moving very little air at all.

Check whether the fan is big enough. Small fans in large bathrooms, or fans sized for a powder room fitted in a family bathroom, are common in older housing.

Leave the door open afterwards where that is practical. Free, and it works.

Squeegee the walls. Ten seconds, and it removes most of the water that would otherwise be evaporating into the room for the next hour. It sounds fussy and it makes a measurable difference.

We can replace a fan on an existing circuit with something more appropriate and improve accessible ducting. New circuits and any alteration to the wiring go to a licensed electrician.

Then deal with the tile

Once the room dries properly, the tile work is worth doing and it lasts.

Regrouting where the grout has genuinely worn or is stained beyond cleaning. Raked out, replaced, and sealed — a good sealer makes the surface less absorbent and slows recolonisation considerably.

The corners, properly. This is universal and it is the most commonly missed detail in any bathroom. Wall-to-wall junctions and the line where a wall meets the shower floor or the bath both move, and rigid cement grout cracks there every time. They want a flexible sealant colour-matched to the grout. In a damp room this matters twice over, because a cracked corner joint is also the route water takes into the substrate.

Sealant at the bath or tray. The joint that fails most often. Old sealant comes out completely rather than getting a new bead run over it, the surface is cleaned and dried thoroughly, and the new joint goes on with the bath filled with water so it is under load in its stretched position.

Checking for the more serious version

Before deciding a regrout is enough, worth doing:

Tap across the tiles. Solid, dead tapping means the tile is bonded. Hollow drumminess means it has let go, and in a shower that usually means the substrate behind is wet.

Look for grout that stays dark when everything is dry. Not growth — that is water in the substrate.

Press low down in the shower. Any softness or flex at the bottom of a wall is a signal to investigate rather than resurface.

The older houses near campus

In the Historic District and around Glen Lennox, bathrooms may be mud-set — tile on a thick mortar bed rather than bonded to a board. That is far more durable than a modern installation and worth keeping where it is sound. Cutting into it for a repair is careful work and the patch has to be built back to the full thickness.

Rental turnovers

A university town has a lot of them, and tile is routine turnover work: cracked tiles, failed sealant, grout that has had several tenancies. One visit for a whole property is far better value than item by item.

Where we stop

Regrouting, flexible joints, sealant, tile replacement, backsplashes and floor tile are our work. Shower pan replacement involving the drain, plumbing behind a wall, and anything requiring a permit go to a licensed trade.

Getting a price

Photograph the shower or bathroom as a whole and a close-up of the worst grout. Tell us whether there is an extractor fan, whether you know where it vents, and how long it usually runs for. Those answers change the recommendation more than the tile photos do.

Chapel Hill is about thirty-five minutes from us, with no travel surcharge.