You want the damp conditions in your crawl space foundation to get better. Should you work on ventilation or dehumidification or both??? You’re torn on where to start and which is going to be the best action and best bang for your buck on getting things dried out under your home.
At Anchor Foundation Repair, when it comes to pier and beam foundations and their problems, no one in the Brazos Valley has crawled and worked in more soggy crawl spaces than us. Though we are not HVAC specialists, we have seen enough moisture damage to know what is needed to improve conditions under these types of elevated foundations.
In this article, we discuss managing crawl space moisture through ventilation and dehumidification. We also cover how to know which is the priority action to take and offer cost approximations.
Definition, Types, and Solutions to Improve Ventilation
Before we dive into how to improve ventilation, let’s define it first. According to good ol’ Merriam-Webster:
Ventilation, noun
ven·ti·la·tion ˌven-tə-ˈlā-shən
1: the act or process of ventilating
2: circulation of air
3: a system or means of providing fresh air
In other words, ventilation means we’re looking to supply fresh air into an area, whether that is a room, building, or in this case, your crawl space. Building on the basic definition of ventilation, we’re trying to *improve* on the conditions in that space. So that means we’re trying to *increase* the circulation of air and provide *more* fresh air to help deal with crawl space moisture issues.
Types of Ventilation
According to this Department of Energy page, there are a few kinds of natural ventilation you can hope or plan for in a home:
- Cross-ventilation,
- Single-sided ventilation, and
- Stacked ventilation.
For a crawl space foundation home, the most logical and practical ventilation is cross-ventilation using natural wind. At least that’s what you’re hoping will work. Unfortunately, natural wind ventilation on its own is not always realistic, especially around here in Central Texas.
I laughed out loud reading the first sentences of that Dept. of Energy page when it said, “Natural ventilation works best in dry climates and in other climates during moderate weather when nights are cool.”
We don’t have what I would call a *dry, moderate climate with cool nights* here in the Brazos Valley. So it kinda makes sense that we need something more than just *hopes and dreams* to create cross-ventilation and improve moisture issues.
Solutions to Improve Ventilation in Your Crawl Space
First, make sure you handle any major drainage or plumbing issues under your home. Then, you can attempt to improve natural ventilation by enhancing your means of passive ventilation, like adding more or bigger vent openings, less restrictive vent coverings, or different skirting material around your home. Still, these actions might not be enough to adequately deal with excess moisture in your crawl space.
Alternatively, you can try to improve ventilation via more active means with the extra help of electricity. Adding mechanical fans designed to push and pull air as needed to refresh the space might be needed to address excess crawl space moisture.
Adding ventilation solutions to your crawl space could cost around $300 or so if you want to DIY it, i.e. crawling in the dirt and doing your own electrical work. Costs could go up to a few thousand dollars if you have multiple vent openings and need to hire the work out to a professional.
Definition, Types, and Solutions to Dehumidify a Crawl Space
We’ll visit with Merriam-Webster again to help us with a definition for dehumidification.
Dehumidify, verb
de·hu·mid·i·fy ˌdē-(h)yü-ˈmi-də-ˌfī
1: to remove moisture from
Well, that seems pretty straightforward, doesn’t it?
Types of Dehumidification Needed
All we gotta do is remove moisture from your foundation. Under a crawl space home, moisture is present in the:
- Air,
- Soil, and
- Even the wood and other materials under your home.
Solutions to Dehumidify Your Crawl Space
In order to dehumidify a crawl space properly, you’ve got to remove moisture from all those sources listed above. The only way to do that is with a dedicated mechanical system aka a dehumidifier. Fortunately, a dehumidifier is capable of removing moisture from the air, soil, and materials in a focused area.
Dehumidification has to be both a continuous and isolated process, otherwise, you’re trying to dehumidify all of Texas and that ain’t gonna happen.
If you can isolate the area for dehumidification, and have a way to remove the accumulation of water removed by the dehumidifier, then dehumidification of a crawl space is doable. Because dehumidification works on moisture in all forms, it is also more effective than ventilation. How effective it is depends on the environment, space, and equipment chosen for the job.
Adding dehumidification solutions to your crawl space is always going to be more expensive, likely costing $10,000 or more. There’s a lot of work to do sealing off most of the vents, installing an exhaust fan, vapor barriers, electrical work, and the dehumidifier itself. Costs also depend on the size of your crawl space and how easy/hard it is to access.
Ventilation vs. Dehumidification: Knowing Which Is Needed
I know I just said that dehumidification can be more effective than ventilation, but I’m not saying it’s always better to choose that approach. I’m also not saying that one is better than the other in all cases.
Depending on your situation, one path will be better than the other so you either have to go down the ventilation path or down the dehumidification path. Doing both doesn’t increase effectiveness and you can’t do both at the same time anyway. Why not? For ventilation, you have to open things up more and for dehumidification, you have to isolate the area.
It’s impossible to do both so you have to choose which is more appropriate in your case.
Here’s some guidance:
- If you only have minor floor concerns or air quality issues and an adequately elevated crawl space, then ventilation may be all you need to address your excess moisture issue.
- If you have bigger problems, known moisture issues, and a low-clearance crawl space, then dehumidification is the path for you to take.
Who Can Help With Crawl Space Moisture Management?
Now that you know what ventilation and dehumidification entail and maybe even which option is best for you, who can help you with this type of crawl space moisture management? You’ve got to find a contractor that does this kind of work. Often, it’s a foundation repair contractor, but there might be another type of specialized contractor for this depending on where you live.
At Anchor Foundation Repair, we don’t fix things that don’t need fixin’, and we don’t try to sell you stuff you don’t need. After 40+ years in business, that’s what’s best for our Brazos Valley community and for exceptional homeowners like you.
In the case of moisture management, we developed special packages to deal with these crawl space issues. No one else was doing what needed to be done for our area’s unique home conditions. We saw the need and filled it with these tailored solutions to keep Brazos Valley crawl spaces dry.
