If you’ve either had someone install grout or have done it yourself, you’ll have to let it dry. That usually means avoiding showering. It also means avoiding using hot water in the bathroom because the steam and built-up humidity can slow the speed at which your grout dries. Unfortunately, it’s also not always a simple matter of predicting how long you should specifically wait.
Grout normally takes 24-72 hours to dry. Under optimal conditions with heat, good airflow, and low humidity levels, most grout will dry in this time. However, you should not shower until you’re certain that the grout is dry. Therefore, you should check the grout every 24 hours until it’s cured.
How Long Should Grout Dry Before Showering
Grout normally dries in 24-72 hours. However, there are many basic types of grout. In addition, you might have a specialty grout depending on location. For example, if you live in a very humid area and install your grout in the middle of winter, you might opt for a fast-drying grout mix. That aside, the type of grout you or the contractor chose will heavily impact normal drying times and conditions. In addition, drying and curing times are completely different. For the best results, you should dry and then cure your shower grout. For a shower floor, that can mean waiting over 7 days before adding sealant on top.
What is Grout and How Does it Work?
Grout is made up of water, cement, and sand. The mix normally depends on the desired finish or waterproofing of the grout. In addition, you’ll get finer or rougher grout based on the amount of space the grout has to fill. So, for a fine line between tiles, you might use grout with no sand at all. For most bathroom floor tiles, you’ll use grout with sand. This impacts the texture. In addition, it impacts drying time. Some types of grout also feature latex or silicone. In addition, resin or epoxy grout is increasingly popular. Epoxy grout is advantageous because it uses a thermoset like urethane, cures over a period of 3-7 days, and then never wears down like cement and sand-based grout.
Grout is chosen based on the size and density of crack or joint to be filled. The material is chosen based on location, desired dry time, and curing properties. Most professional grouters use pressure to grout tile as firmly as possible.
Drying grout normally requires 24-72 hours. During this period, the water mixed into the grout evaporates. If you get grout wet during this period, it can wash away – because it hasn’t fully solidified. Any water or moisture on the grout before it’s dry will increase the time it takes to dry. And, most importantly, if it mixes into the grout or soaks in, it can weaken the grout. This means tiles are more likely to come up and grout is more likely to erode. Essentially, it is crucial to wait at least 24 hours, test your grout to see if it is dry, and if not, wait another 24 hours.
Curing is the process of allowing the grout to fully harden. This is most important when you’re using resin and epoxy grouts. These use polymers like urethane instead of cement or sand. This means that once you mix a hardening agent with the resin, it has a certain amount of time until it is permanently set. Often, that time is 3-14 days. However, some specific brands will recommend waiting longer. At the same time, the curing stage requires less care. Grout that is dry but not fully cured can occasionally get wet. You should simply ensure that you allow it to dry out fully before moving on to the next step.
Most grout should have a final layer of sealant applied as a last step in the process. That’s especially true if you’re using sand-based grouts, which can allow a lot of water through. It might not be necessary if you’re using a latex grout – which already has sealant in the grout. Sealant should never be applied until the grout is fully cured because it traps moisture under the grout. If the grout is not fully dry, that moisture will cause the grout to erode, and your tiles will eventually come up.
The full duration of this process depends on what type of grout you have. Normally, the most important factor here is brand. Why? A grout mix from one brand might have the same name as another, but if they’ve used different agents or a different grind of sand, the drying and curing times will vastly differ.
Different Types of Grout
There are several major types of grout and all of them offer advantages. In most cases, they’re also recommended for specific best-case or best-fit scenarios.
Cement grout or cementitious grout is the most common type of grout. It’s primarily made of Portland cement with additives and the option to add dye or colorant.
Sanded – Sanded cementitious grouts use sand as a filler particle, allowing you to fill larger areas with less grout. Here, sand particles can vary significantly in size depending on the size of the gaps between tiles and whether the grout is for the floor or the walls. Walls normally need finer grout to ensure that tiles are firmly bonded to the wall and each other. Floor grout might have larger gaps and therefore can use larger particles of sand. As a general rule, sanded grouts are also used in wider cracks. You’ll rarely see them in cracks less than 1/8th of an inch.
Sanded grout also dries most quickly. Sand is porous, allowing both water and air to seep through. This means you can normally expect fully dry sanded grout within 24-48 hours. If it’s not, you likely have humidity or cold issues.
Unsanded – Unsanded grout is made up of cement and possibly some other particles. This makes them suitable for very fine cracks, especially those 1/16th to 1/8th of an inch wide. Unsanded grout can crack if used in too large of a space. It also takes longer to dry, because there’s less porous material.
Latex-Modified – Latex-modified cement grouts use a latex polymer additive to waterproof the grout. This can reduce the need to seal your grout. However, it also usually means it will take longer to dry. Expect to add an extra day to average drying times.
Epoxy grouts are also commonly used in home projects. However, they are most common in kitchens rather than in bathrooms. If you have chosen to use them in your bathroom, you should expect to wait up to 7 days before using your shower. Here, this is important, because if the epoxy fails to set properly, it will never set. Epoxy grouts also take more skill to set. Once you mix the ingredients, the epoxy can harden fairly quickly. The result is that you have to apply and use all mixed grout very quickly.
Common Drying Times for Popular Grout Mixes
If you’re installing grout yourself, you can always check the package. In addition, some grout has specific instructions, such as misting the top of the grout to ensure it doesn’t crack while drying. In almost every case, drying times are based on 50 degrees Fahrenheit or higher in a cool, dry space.
- SimpleGrout® PreMixed Grout – 24-72 hours
- QUARTZLOCK2™ RAPIDCURE™ Grout – 72 hours
- Prism Grout – 4 hours for foot traffic; 24 hours for water exposure
- Polyblend Grout – 24 hours for foot traffic; up to 72 hours for water exposure
- Ardex FL Grout – 90 minutes for foot traffic – 72 hours for water exposure
- QuicTile Pre-Mixed Urethane Grout – 72 hours
You’ll also have to check the sealant dry time before you apply it to know how long you have to wait after applying sealant.
4 Factors That Affect Grout Cure Time
If you’re wondering how long your grout should specifically take to cure, that depends on the grout itself. However, there are also environmental factors which will impact how your grout dries and cures.
1. High Humidity/Moisture
The higher the moisture level of your bathroom, the more slowly grout will dry. For example, if you frequently run hot water and the bathroom steams up, that will slow grout drying. If towels, paper towels, or the floor are damp or condensate – you’ll probably see issues with grout drying. Often, bathrooms condensate because they are colder or warmer than the room or a wall around them. You can resolve this by using air conditioning or heating to keep the room at a stable temperature until the grout cures.
2. Low Airflow
Moisture needs airflow to evaporate. This means that if your grout does not have any airflow, it will take longer to dry. That means that unventilated bathrooms can take longer to dry. In addition, if you’re sealing in grout with caulk or blocking it in with larger tiles that restrict airflow, grout takes longer to dry.
3. Epoxy Content
Epoxy can take up to 7 days to fully cure or set. If it’s exposed to light, is moved, or is mixed improperly, it might have trouble setting. In addition, if it’s exposed to water before it’s fully dried, it might never fully set. Epoxy grout always takes longer to dry. However, you also have to be careful with it.
4. Cold Weather
Water evaporates when it is warm and dry. If your weather is very cold, e.g., under 50 degrees Fahrenheit, you’ll likely have to double the wait time for drying your grout. If it’s too cold, your grout might just never set properly, which can cause structural problems with the grout.
The sand content, grit size, and chemical makeup of your grout will always impact drying times. Unfortunately, there’s no way to check this if you don’t have the package or the brand name and grout name. If you do, most manufacturers will offer min/max drying times and recommendations in case things go wrong.
How to Make Grout Dry Faster in 2 Effective Ways
Grout will always dry eventually. However, if you’re waiting to use your shower, you do want grout to dry as quickly as possible. Here, you can try one of four different strategies to keep your bathroom cool, dry, and at a consistent temperature.
Increase Airflow – You can use a humidifier, open doors or windows, or use a fan to circulate air and improve the drying speed of your grout. This will improve how quickly grout dries. However, if you have a fan and fine or unsanded grout, you might have to mist the grout to keep the top from cracking.
Regulate Temperature – If the temperature is too cold or the inside/outside temperature is too high or low, grout won’t dry. That may relate to moisture buildup and condensation. It might also relate to the bathroom simply being too damp. Here, you can resolve the issue by installing a temporary heater or air conditioner to maintain the temperature while the bathroom dries. In either case, make sure you add ventilation to offset any condensation that might be caused by the heating.
Here’s What to DO If Grout is NOT Drying
If your grout just isn’t drying, it’s important to look into why. This is especially important if you have an epoxy grout. For example, this might indicate the mix is wrong and it will never dry. However, chances are, part of the bathroom is restricting airflow or trapping moisture, which might prevent your grout from drying.
- Inspect the area. Is there evidence of water buildup or air cavities behind the tile or grout? Can you take a tile off to check?
- Check airflow. Is the bathroom getting enough ventilation?
- Keep waiting to shower. Don’t use the shower until the grout is dry and hard. Then, allow it to cure and seal it before using the shower.
If you’re asking why grout isn’t drying off, after it’s been dried and sealed, the issue is almost always airflow. Here, any bathroom or space needs sufficient airflow to allow moisture to evaporate. If you’re having problems with mold or moisture buildup on grout, you can usually look at improving airflow to fix the problem.
Why It’s Necessary to Seal Shower Grout
Grout is normally made of Portland cement and sand. This is porous and absorbs water. Therefore, if it is not sealed, it will absorb water. This can result in a few scenarios, none of which are great for your shower. The first is that most materials expand when they absorb water. Over time, this can force your tiles apart, can cause cracks, and will weaken the grout. The second is that if grout fully absorbs water, it takes time to dry. If grout constantly stays wet, it becomes a breeding ground for mold and bacteria. Neither are things most people want in their bathroom.
Sealant keeps water out of the grout, so you don’t have these problems.
If you keep your bathroom warm, dry, and have good airflow, most grout will dry within 24 hours. You can then shower if you want to. However, you shouldn’t really get your grout wet until after you’ve sealed it. Most grouts take 3-7 days to fully cure. This means it’s generally a good idea to look for a shower elsewhere while your grout dries. That aside, if you really must, it’s usually safe to shower as soon as you can touch your grout and it’s hard to the touch. Just make sure you don’t try for at least the first 24 hours to avoid damaging the grout.