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In this guide, I will show you how to fix large gap between tub and floor tile or between tub and wall. As we are all aware, water can be a natural enemy of homeowners. It has a certain way of getting into the tiniest of openings and playing havoc.
In the bathroom in particular, there are multiple avenues through which water can permeate. When a bathtub and flooring is installed, the two may sit together so that there are no gaps.
But over time, the house will settle and there can be minor shifts between the floor and bathtub. This gap puts stress on the caulking joint, leaving it susceptible to water invasion.
When this happens, the caulking has to be removed and replaced. The good news is that even the most novice of DIYers out there can do the job in short order.
How To Fix Large Gap Between Tub And Floor Tile
Since there is now a gap between your bathtub and the floor, the old caulk is no longer considered trustworthy. It is likely that the caulk has completely separated either from the wall or tub, though it may still have the appearance that it is hanging on.
Cutting the Caulk Free
You will have to start by cutting out the old caulking from the joint. Use a razor scraper or utility knife to cut along both sides of the joint.
Just make sure that you don’t press too hard. For razor scrapers, too much pressure can snap the razor off. When you have cut the old caulk free, pull it up and away from the joint.
You can then slip your knife on the underside of the caulk to finish getting it up. Keep going until you have managed to remove all of the old caulking around that joint.
Cleaning the Expansion Joint
You will also need to clean out that expansion joint. Depending on the gap distance, there may be loose debris within that joint. Make sure that you vacuum that loose debris out as you need a clean, clear surface to adhere the caulk to.
You can create an effective household mixture using a quarter cup of water and a quarter cup of bleach. It is a good idea to use this mixture anyway but can be particularly effective if you happen to notice a buildup of mildew.
Using your concoction and an old toothbrush, get in there and scrub to loosen and remove any caked on or tough mildew. You will have to rinse out the bleach from the joint and give it time to completely dry before you can move on to the next step.
Fill the Tub and Apply Caulk
When the joint has completely dried, it is time to add water to the tub. The point here is that it will put the walls of the bathtub at their widest point while also narrowing the expansion joint to its most narrow point.
When you are done, you will drain the water out and the gap should be the perfect width. If you don’t add the water, there is a chance that the caulking may bulge from the joint whenever the tub is in use.
Get your tube of silicone caulking and cut the tip off using a utility knife. You will want to make a hole in the end that is about the size of the average metal coat hanger.
You can always go a little bigger with the hole but be careful as there is no going back. With your caulk ready, you can now get to the application. Steadily run a bead of caulking along that expansion joint.
It helps to dampen the tip of your index finger with a little dab of water. You can then drag your finger over the surface of the damp caulking.
That will create a smooth, even joint. Make sure that you wipe off that excess caulking from your finger using a rag. Finally, empty out the tub and give the caulking a chance to dry before you use the tub again.
In most cases, 24 hours should be more than enough to ensure that the caulk will dry properly. The gap between the flooring and your tub should be gone.
How to Fix Gap Between the Tub and Wall
Gaps between the tub and the adjoining wall are actually done on purpose. This is the expansion joint and gives some space for movement between the wall and tub. The good news is that, no matter how big the gap is, it can be filled with caulk.
Dealing with Gaps up to a Quarter Inch
For this purpose, you should be fine with just a single bead of caulking. If there is tile on that adjoining wall, make sure you pick a color of caulk that matches the tile grout.
Should the gap be 1/8-inch or less, you can use regular caulk. Anything bigger than that and you would want to switch to a sanded caulk.
As is the case with the flooring, make sure that the gap is both clean and dry before starting. You can then squeeze out a thin bead of caulk over the space.
Make sure that the gap is completely filled before wetting down your finger and smoothing the caulk so that it fits evenly throughout the gap.
Dealing with Gaps up to Half an Inch
When you get above that quarter-inch mark, going up to half an inch, you will need to add a second bead of caulk to get the job done.
The beads must be set side by side so that they create an even coverage between the tub and adjoining wall. Start by applying a single bead along the edge of the tub and a second bead along the wall’s edge.
Make sure that you smooth it out using a wet index finger, joining the two beads of caulk together carefully. Have patience here; too much pressure or moving too quickly can lead to the gap being uneven.
You may also wind up pushing the caulk in too far. When that happens, you have to remove the caulk and start over again.
Very Wide or Deep Gaps
When you get above half-inch gaps, it can be the wild west in a way. The good news is that this method can address gaps up to six inches wide.
That’s because a backer rod will need to be applied before using the caulk. Backer rods are basically flexible foam tubes that come in different densities.
They can also be comprised of a number of materials, so make sure to buy one that is made to be used in wet areas. A nonporous option is ideal as it won’t absorb water or moisture.
You will have to push the backer rod down and into the gap. It should fill the gap completely so that the top of the backer rod is barely below the surface of the gap.
When the backer rod is in place, it is time to spread the caulk. Spread a bead on each side of the point where the rod joins the wall and tub.
The caulk will join the wall, tub, and backer rod together to fill the space. Make sure you smooth out the caulking with a wet index finger as you would in the previous examples.
Hello, my name is David Zal and I’m a plumber with more than 20 years of experience based in Englewood (Florida). I like to teach normal people how to make easy fixes in their homes. I believe that a lot can be achieved just with DYI and that’s why I started this blog.