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7 Ways to Support Floor Joists in a Crawl Space

7 Ways to Support Floor Joists in a Crawl Space

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Having a crawl space foundation is something that can turn out great. Many people have crawl space foundations.

As long as the crawl space is designed properly, it should work perfectly for your home. It’s important for the floor joists to be supported the right way.

How do your support floor joists in a crawl space, though? If you’ve never had a crawl space before, you might not understand what needs to be done.

Continue reading to learn everything that you need to know about the floor joists in the crawl space. This should help you to get the best results.

Floor Sagging Issues

When living in a home with a crawl space foundation, you might notice that you’ll encounter floor sagging issues. If the floor is sagging, it’s a sign that things are wrong.

Older homes with crawl spaces are more likely to experience these issues. There could be many different things wrong that you will need to remedy.

Sometimes the floor will sag because there’s too much moisture in the crawl space. Excessive moisture causes issues with rotting that makes your floors and the joists experience problems.

You can remedy this by installing a vapor barrier to protect the crawl space from moisture. Buying a 6-mil vapor barrier and installing it along the dirt floor will work well.

Simply ensure that the barrier is installed properly with no gaps. If there are issues with mold in the crawl space, you might need to call in a specialist to take care of the removal.

This can cost a bit of money, but it’s imperative to protect your investment in your home. You want to make sure that your floors are supported because you don’t want someone to fall through the floor.

Once you notice that the floor is sagging, you should take steps to change things for the better. Ensure that the crawl space is protected from moisture and that mold isn’t an issue.

After this has been confirmed, you can proceed with supporting the floor joists. There are several helpful things that you can do that will make your floors stronger.

1 – Consider Installing Sister Joists

You could take the time to install sister joists to support the floor better. Install a new joist next to any joists that have become damaged over time.

The sister joist will take a lot of the strain off of the old joist. Even if the joist isn’t damaged, it’s likely worthwhile to install sister joists.

Doing this supports the floor better and will help to prevent issues with sagging. You should have a much easier time keeping the floor held up properly if you have sister joists installed at strategic locations.

There isn’t any reason not to use this idea when you’re dealing with sagging floor issues. This is something that can help, but you might need to solve other problems such as rotting floors if you’re dealing with moisture issues.

2 – Install More Beams

Much like installing sister joists, installing more beams can help out. The floor joists can easily be strengthened if you add more beams to support them.

Additional beams make it so there will be less pressure on the joists. It can help to alleviate problems with sagging floors.

3 – Bridging Can Help

Bridging is an idea that can support the floor joists quite a bit. You might not know this, but floor joists can potentially twist or start learning sideways.

When this occurs, the floor joists won’t be nearly as strong as they should be. You can use bridging to make things stronger.

This method involves installing wooden or metal strips between the joists. Install them in an “X” pattern to keep the joists from being able to move sideways.

It makes things more stable and you shouldn’t have to worry about twisting. This simple little trick is highly recommended because it can make a huge difference.

4 – Blocking

Blocking works almost the same as the bridging method mentioned above. The difference is that you’re using wood pieces that are the exact same width as the space between the joists.

These are put in place to block the joists from being able to move. It’s the same concept as bridging, but it’s just executed differently.

5 – Brick or Concrete Columns

Another option is to install brick or concrete columns. These columns can be installed underneath the beams to add support to the floor joists.

This is a fairly simple way to support the floor joists that you can use in a pinch. Many professionals will place brick or concrete columns in crawl spaces when dealing with sagging floor problems.

6 – Try Using Jack Posts

Using jack posts can help if you’re experiencing issues with settlement. Sometimes there will be issues with the ground settling and that will impact your crawl space foundation.

When this happens, it’s possible to use jack posts to support the weight of the home. Hopefully, it won’t be necessary to use something like this in your situation.

You might need to call foundation specialists if you’re experiencing substantial issues, though. Sometimes you’ll need the expertise that they can provide.

They can tell you if you need to take certain steps to protect your home. Depending on what you’re dealing with, you might need to take steps such as using jack posts rather than just supporting the floor joists with sister joists or other such methods.

7 – Replace Flooring

Sometimes the issues you’re experiencing won’t be directly related to the joists. For example, your flooring might have rotted due to being exposed to mold and moisture for long periods of time.

The subfloor could have rotted so much that it has started to sag. It has become weakened and it’ll eventually break down completely if you don’t replace it.

Such issues aren’t too uncommon when you have a dirt crawl space floor. If you didn’t install a vapor barrier, the moisture problems might have become too much of an issue.

People who live in humid parts of the world are more likely to have such problems. For example, if you live in the Southeastern United States, it’s very humid there.

The humidity level being higher makes moisture issues that much more likely. This is why many people choose to shy away from crawl space foundations in those areas.

In some places, a vapor barrier will be a necessity to combat problems with moisture. So you might experience significant problems if you don’t install one after several years of living in the house.

If it becomes necessary, you should replace the subfloor that has been damaged. You can call local flooring companies to do the work if you’re not confident that you can do things yourself.

Final Thoughts

There are many things that you can do to support the floor joists when you have a crawl space foundation. You can try adding sister joists to take some of the strain away from the old joists.

You might want to try using bridging or blocking methods to keep the joists from being able to turn sideways or twist. Even adding concrete or brick columns to support the floor can be a good idea.

Some people choose to install more beams and others will simply look to fix problems that made the floor joists weak in the first place. Remember to fix any issues with moisture and mold in your crawl space as soon as you can.

So long as you take the right steps, you can protect your home. Figure out the best course of action and then move forward.


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