Finding the right homemade house wash solution can save you a ton of money compared to those overpriced, chemical-heavy jugs you find at the big-box hardware stores. If you've spent any time looking at your siding lately and realized it's looking a bit more "earthy" than it used to, you're probably itching to give it a good scrub. The good news is that you likely already have most of what you need sitting under your kitchen sink or out in the garage.
Cleaning the exterior of your home isn't just about making the neighbors happy; it's about maintenance. Dirt, algae, and that weird green stuff that grows on the north side of the house can actually damage your siding over time if you let it sit there. But you don't need a professional crew or a $500 bill to get things looking new again.
Why Mix Your Own Cleaner?
Honestly, the biggest reason people switch to a DIY approach is the cost. Those pre-mixed solutions are mostly water anyway. When you mix your own, you're paying for the active ingredients and skipping the fancy packaging. Plus, you get to control exactly what's going on your house. If you have kids, pets, or a prize-winning rose bush, you might be a little wary of spraying harsh industrial degreasers everywhere.
Another perk is that you can tweak the "recipe" based on what you're actually dealing with. If you just have some dust and cobwebs, you don't need the heavy-duty stuff. If you have a legitimate mold colony forming on your vinyl siding, you can beef up the formula to handle it.
The Basic Ingredients You'll Need
Before we get into the specific mixes, let's talk about the heavy hitters. You don't need a chemistry degree, but you do need to know what does what.
Dish Soap: This is your surfactant. It helps the water "cling" to the siding rather than just running straight off. It also breaks down oils and grease. Blue Dawn is the classic choice here because it's tough but relatively gentle on surfaces.
Distilled White Vinegar: Great for cutting through grime and light mineral deposits. It's also a natural way to kill some types of mold without reaching for the bleach immediately.
Oxygen Bleach (OxiClean style): This is a favorite for people who want to avoid chlorine bleach. It's much safer for plants and won't bleach your clothes if you get a little splash on your shirt. It's effective at breaking down organic stains like algae.
Chlorine Bleach: The "nuclear option." It kills mold and mildew instantly. You have to be careful with it, but sometimes it's the only thing that gets the job done on a really neglected wall.
TSP (Trisodium Phosphate): You'll find this in the paint aisle. It's a heavy-duty cleaner that's amazing for getting rid of really stubborn soot or chalky oxidation.
A Reliable All-Purpose Recipe
For a standard homemade house wash solution that works on vinyl, wood, and even brick, this is a great starting point. It's effective enough to see a real difference but won't melt your lawn.
Mix about one gallon of water with a quart of white vinegar and maybe half a cup of dish soap. If you've got a lot of surface area to cover, you can scale this up in a five-gallon bucket. The vinegar does the cleaning, and the soap ensures the mixture stays on the wall long enough to actually work.
I usually suggest using warm water if you can. It helps the soap dissolve better and seems to loosen up the dirt a bit faster. Just give it a good stir—don't shake it too hard or you'll end up with a bucket full of bubbles and no liquid.
Dealing With Mold and Mildew
If your house has those unsightly black spots or green fuzzy patches, the vinegar mix might not be strong enough. This is where you might want to bring in the oxygen bleach.
Mix one cup of oxygen bleach powder with a gallon of warm water. Make sure the powder is completely dissolved before you put it in a sprayer, or it'll clog the nozzle and give you a real headache. This solution is fantastic because it's generally "plant-safe," meaning if some drips onto your bushes, you won't wake up to brown leaves the next morning. It works by releasing oxygen bubbles that physically lift the organic growth off the siding.
If the mold is really bad—like, "I haven't washed this house since 2005" bad—you might use a diluted chlorine bleach solution. A ratio of one part bleach to four parts water is usually plenty. Just remember: never mix bleach with vinegar or ammonia. That creates toxic fumes that you definitely don't want to breathe in.
How to Actually Apply the Solution
You've got your bucket of suds, now what? You have a couple of options.
The easiest way for most DIYers is a simple pump-up garden sprayer. They're cheap, and they let you apply the solution evenly without much waste. If you're using a pressure washer, check if it has a "soap tank" or a "downstream injector." Most pressure washers have a specific nozzle (usually the black one) meant for applying chemicals at low pressure.
Pro Tip: Always wet the siding with plain water first. If you put the cleaning solution onto dry siding, it can soak in too deep or dry too fast, leaving streaks that are a pain to get off.
Work from the bottom up when applying the soap. If you start at the top, the soapy water runs down over the dry dirty spots and creates "clean streaks" that are weirdly hard to even out later. Once the soap has sat for about 5-10 minutes (don't let it dry!), rinse it off from the top down.
Protecting Your Landscaping
Even a relatively "green" homemade house wash solution can stress out your plants if they get drenched in it. Before you start, give your shrubs, flowers, and grass a good soaking with the garden hose. Wet leaves won't absorb the cleaning solution as easily as dry ones.
If you're using the stronger bleach-based mix, you might even want to throw a lightweight plastic tarp over your most sensitive plants. Just don't leave the tarp on too long if it's a hot day, or you'll end up steaming your hydrangeas. Once you're done rinsing the house, give the plants another quick spray with fresh water just to be safe.
When to Scrub and When to Spray
Sometimes, the spray-and-rinse method doesn't quite cut it. If you have textured siding or deep-set grime, you're going to need a brush. You can buy long-handled soft-bristle brushes specifically for house washing.
You don't need to scrub like you're trying to take the paint off. Just a light agitation is usually enough to break the bond between the dirt and the siding. I usually spray a section, let it dwell for a few minutes, give it a quick once-over with the brush, and then rinse. It's a bit more work, but the results are night and day compared to just spraying.
Final Thoughts on Safety
It sounds obvious, but be careful on ladders. If you can reach the second story with a long pole or a high-pressure nozzle from the ground, do that instead. Wet siding is slippery, and the ground around your house is going to get muddy and slick while you work.
Also, wear some eye protection. Even if you're using a mild vinegar mix, getting a face full of mist when the wind shifts is no fun. If you're using bleach, wear old clothes because you will get white spots on them.
Keeping your home's exterior clean doesn't have to be a massive, expensive production. With a little bit of elbow grease and a simple homemade house wash solution, you can get that "just painted" look without the professional price tag. Just pick a cool, overcast day so your cleaning solution doesn't dry too fast, grab your bucket, and get to it. You'll be surprised at how much better the place looks after just an afternoon of work.