If you have tile anywhere in your old house, you just might have problems with grout. Over the years I have dealt with grout that was yellowed, blackened, chipped, crumbling and even growing its very own mold colony. Grout problems are especially prevalent in the bathroom, where humidity, moisture and other issues create potential for messy grout.
For a contractor, grout issues would be an easy fix. But for a homeowner who has never handled a caulk gun, fixing grout is more difficult than it seems at first blush.
How to fix old grout
First, determine what you really need. Is the grout falling apart? Or is it simply weathered and in need of a touchup? Old grout that has yellowed over the years might just need a thorough scrub with appropriate cleansers. But if it is crumbling or falling apart in chunks, it’s time to repair and replace.
Look for caulk that is close in color to what you already have. Acrylic caulk is easy to work with, very forgiving when fresh and free of toxic gases during application. Though it isn’t as durable as urethane caulk, the ease of working with acrylic is great for homeowners who are trying their hand at fixing grout for the first time.
Once you have the caulk, set the stage with the other things you will need. This includes a drop cloth or other protective covering to catch the old grout and keep the area clean, a utility knife or scraper to get rid of the old grout, a small chisel and hammer, a pair of latex gloves, a putty knife and a few damp rags.
Start by gently removing the areas of crumbling or cracked grout. You might be able to handle this with the scraper or utility knife, but for stubborn areas, a small chisel and hammer will do. Take your time — you don’t want to damage the surrounding tiles! Carefully clean out the grout, brushing away the residue as you work. When you have completed a section, it’s time to add the caulk.
Using a caulk gun, insert the caulk into the space between the tiles. Press the caulk into the area with a putty knife or scraper. While wearing the latex gloves, gently run your finger across the caulk to create a concave look between the tiles. Wipe away any excess caulk, then smooth it down one more time. You should now have a clean, neat, concave line of caulk between the tile.
Keep going! Work on one small section at a time. Always work fast once you have applied the caulk, as it will dry quickly and you need plenty of time to work with it before that happens. Be prepared for a few mistakes when you first begin — smoothing down the caulk isn’t as easy as it might seem, and it can take a few tries to get the hang of it.
Finally, let the caulk cure for a few days before you turn on the shower. In an older house you might have a serious job on your hands, so be sure to give yourself at least a weekend to do the grout work. If any of the tile is uneven, seems to be bowing out from the wall or otherwise seems like a bigger job than what you are comfortable with doing, get in touch with an old-house contractor for assistance.