Crumbling grout lines rarely mean the tile has to come off the wall. Cracked, stained, or soft joints can usually be cut out and packed with fresh material while every tile stays exactly where it is. For a careful homeowner that is a weekend's work; for a tile contractor it is routine. What follows is the sequence that holds up in a Puget Sound bathroom, where the damp never entirely leaves.
Read the joints before you touch them
Grout fails in patterns, and the pattern tells you something useful. Hairline cracks tracking along a single line often mean slight movement behind the tile. Joints that have gone dark and spongy in the lower courses point at water sitting somewhere it shouldn't. Powdery grout that brushes away under a fingernail has simply lost its binder after years of wet-and-dry cycling.
Before mixing anything, look past the grout itself. Peeling paint on the far side of the wall, a soft spot in the subfloor at the threshold, or a musty smell that lingers after the fan has run all suggest moisture has already moved behind the tile. Sorting that out first is the difference between a repair that lasts and one that looks good for a season.
The local climate does not help. Bathrooms around Everett spend much of October through April at high humidity, and houses built before modern ventilation standards often have an undersized fan or none at all. Where the walls around the enclosure are already showing growth, it is worth addressing mold on the surrounding walls before you seal fresh grout over a damp substrate.
Clean before you cut
Soap film and mildew will keep new grout from bonding, so the enclosure gets a thorough wash first. A mild acidic cleaner lifts mineral scale and scum; a stiff nylon brush works it out of the joints. Rinse well, then let the walls dry completely rather than working on a surface that is merely towel-dry. If the enclosure has an obvious leak at the base or a failed bead of sealant at the wall-to-pan joint, repair that now, while the joints are open and accessible.
Cutting out the old grout
The job needs less equipment than people expect: a hand grout saw, or an oscillating multi-tool fitted with a grout blade for long runs, plus a carbide scraper for corners and a wire brush for cleanup. Work in light passes and keep the blade centred in the joint. The glazed edge of a tile chips easily, and most of the damage done during regrouting happens when someone levers a blade sideways against it. Try a low, inconspicuous corner first to learn how the tile responds.
Take the old material down far enough that the new grout has something to grip — roughly two-thirds of the joint depth is a reasonable target. Vacuum the dust out as you go, brush the joints clean, and let everything dry again before mixing.
Packing the new joints
Match the grout to the joint width: unsanded for narrow lines, sanded once the gaps widen, and check the manufacturer's guidance for anything unusual. Mix to a stiff consistency, let it slake for the stated time, then remix briefly. Work a manageable section at a time, holding the float at an angle and pressing the material firmly into each joint rather than skimming it across the surface. Too little and you leave voids that collect dirt and water; too much and you are left with ridges to clean off.
Once the grout has taken its initial set, wipe the faces diagonally with a damp sponge, rinsing often so you are not dragging slurry back into the lines. Any remaining haze comes off the following day with a dry cloth. Where a surround has failed across most of its lines rather than in one patch, taking the whole thing back to open joints in a single pass gives a far more even colour than spot-filling ever will — a full tile regrouting walkthrough covers that approach in order. Cementitious grout gets a penetrating sealer after it has fully cured.
What quietly undermines new grout
Fresh joints are only as dry as the pan beneath them. A shower that drains slowly leaves a film of standing water against the lowest course of tile after every use, and no grout stays sound under that, however well it was packed. Drain lines in older parts of Snohomish County accumulate hair, soap, and mineral scale, and in the oldest neighbourhoods roots work their way into clay joints further down the line. If water still sits in the base a minute after the valve is off, clear the drain before you regrout — Everett Drain Cleaning, Snohomish County handles that side of the work.
Ventilation closes the loop. Run the fan during the shower and for a while afterwards, pull a squeegee down the walls, and keep harsh acidic cleaners off the new joints. Done in this order — diagnose, clean, cut, pack, cure, seal — regrouting is one of the few bathroom jobs that gives back a nearly new surround without a single tile leaving the wall.