What’s the point of having a crawl space if you can’t access it?
You need to be able to access your crawl space for emergencies, but how big does a crawl space access have to be?
Read on for more about the requirements for crawl space access and other factors to consider. This article also tells you when it’s too risky to access a crawl space.
How Big Is a Crawl Space Opening?
The International Residential Code (IRC) requires you to build access to the crawl space underneath your house.
Section 408.4 of the code states that floor access openings should be at least 18″ x 24″. It also sets the measurements of openings through an outer wall to 16″ x 24″.
That being said, we recommend that you enlarge your access opening a little. After all, you don’t know who might have to get into your crawl space.
A slightly larger opening can be more convenient for you or any handyman, regardless of his size. Such ease of access would make a maintenance job a lot easier.
What Is the Minimum Height for a Crawl Space?
According to the IRC, the height of any crawl space shouldn’t be less than 18 inches. Otherwise, it won’t be accessible to an adult.
The height of the crawl space is the distance between the bottom side of the house’s floor joist and the ground beneath the house.
Construction builders usually build houses with this in mind. It’s rare to find a crawling space with a height less than 18 inches.
How High Should a Crawl Space Be?
The height of the crawl space floor is determined by the amount of groundwater under the house.
Generally, the floor of a crawl space can be at the very bottom of the footings unless the groundwater rises to more than 6 inches.
In addition, if you expect any drainage problems in your crawl space, raise the floors high to the ground level.
That’s a crucial precaution to avoid high moisture levels, which may cause mildew, mold, and other major issues.
3 Other Factors to Consider When Planning Your Access
Although these aren’t officially required by the IRC, here are some further ideas to consider:
1 – The Space By the Access
What you do in the space right in front of the access depends on the position of your crawl space. For instance, if your access opening is below grade level, you need a clearance in front of it.
This clearance or well should be 16 inches in depth and 24 inches in width. It provides a convenient entrance for the crawl space.
2 – Access Panel
If you add an access panel, it should be easily removable. In other words, you shouldn’t need any special equipment to remove it.
Still, you need to seal the panel to prevent critters and other animals from getting under your house.
3 – The Content of the Crawl Space
What you put inside the crawl space is an important factor that determines the size of the opening.
For instance, if you place any mechanical devices or electrical panels in your crawl space, you should have a wider opening. This way, it’s more convenient to perform any maintenance job required.
3 Reasons a Crawl Space Is Too Risky to Enter
An inaccessible crawl space is too dangerous to enter, so don’t bother creating a way in. Who knows what’s inside or how tight it gets?
In addition, here’s a list of three cases in which a perfectly accessible crawl space looks potentially dangerous:
1 – Water or Liquid
Any water or liquid puddles inside the crawl space or in the clearance right outside might raise a flag. If it’s water, there might be a risk of electrical shock.
Even worse, it might not be water at all. This liquid can be a sign of chemical contamination, especially when combined with a pungent chemical odor.
2 – Excessive debris
Don’t enter a crawl space that has excessive debris, such as splinters, rocks, and nails. These materials can host rodents and other animals.
Remember that you typically move slowly in a crawl space. Thus, be extra alert for any signs of insects or snakes. In addition, rodents might cause some infections.
3 – Asbestos or Mold
If you see any sign of mold or asbestos, be extra cautious with this crawl space.
In addition, any insulation damage means that the place is infested. Thus, you shouldn’t get inside without protective gear.
We also recommend that you don’t take any equipment out of the infested crawl space. This way, you can prevent the spread of such infestation.
So how big does a crawl space access have to be?
The answer to this question depends on whether you install a floor access opening or cut an opening in an outer wall.
The IRC dictates that every crawl space should be accessible. According to the code, a floor opening should be 18 inches in height and 24 inches in width. On the other hand, if the opening comes from an outer wall, it should be 16 inches high and 24 inches wide.
If a crawl space doesn’t abide by these rules, it might be too risky to enter.
I have a bachelor’s degree in Computer Information Systems and over 10 years of experience working in IT. As a homeowner, I love working on projects around the house, and as a father, I love investigating various ways to keep my family safe (whether or not this involves tech). I’ve also played guitar for almost 20 years and love writing music, although it’s hard to find the time these days.