If you're trying to figure out where should drainage holes be on uPVC door frame because you've noticed a bit of water sitting where it shouldn't, don't worry—it's a common puzzle for homeowners. These little holes, often called "weep holes," are the unsung heroes of your home's weatherproofing, but they aren't always obvious. If they're blocked or missing, you'll definitely know about it when the next big storm hits.
The basic idea is that no door is perfectly, 100% watertight against the elements forever. Rain gets driven by the wind, and eventually, a little bit of moisture might sneak past a gasket or a seal. Instead of letting that water sit inside the hollow chambers of the uPVC frame and rot your floorboards or cause mold, the frame is designed to channel it back outside through specific drainage points.
Spotting the internal drainage holes
When you open your door and look down at the bottom part of the frame—the bit we call the rebate—you should see at least two small slots or holes. These are usually spaced out toward the corners. Their job is to catch any water that runs down the glass or gets past the weather seals.
If you look closely, you'll notice the bottom of the frame isn't flat; it's usually sloped or has a little channel. This is intentional. Gravity does the heavy lifting, pulling the water toward these internal holes. If you've got a wider door, like a set of French doors or a large patio slider, you might find three or four of these holes spaced out along the length of the track.
Where the water actually exits
Now, if water goes into the frame, it obviously has to come out somewhere. This is where the external drainage holes come in. On most standard uPVC doors, you'll see these on the very bottom face of the frame on the outside.
Usually, they're covered by little plastic caps that match the color of your door. These "weep hole covers" aren't just for looks; they help stop wind from blowing directly into the frame and prevent spiders from turning your drainage system into a high-rise apartment. If you look under the front edge of the frame, you might find the holes there instead—this is called "concealed drainage." It's popular because it looks a bit neater, but it can make it slightly harder to see if they're working.
Why location matters so much
If the holes are drilled too high, the water will pool at the bottom of the frame before it ever reaches the exit point. This leads to that annoying "sloshing" sound you might hear when you move the door. On the other hand, if they aren't lined up correctly between the inside and the outside, the water just gets trapped in a different chamber of the uPVC.
Most manufacturers have a very specific template for where these should go. They're usually about 50mm to 100mm from the corners. This ensures that the water doesn't just sit in the ends of the profile. If you've got a door that's constantly leaking inside despite the seals looking fine, it's worth checking if these holes were actually drilled in the right spot during the manufacturing process. It doesn't happen often, but human error is a thing.
What happens when they get blocked?
Over time, all sorts of junk finds its way into those drainage channels. We're talking about dust, pet hair, bits of dead leaves, and even moss. When that stuff mixes with water, it turns into a kind of sludge that blocks the holes.
When the drainage is blocked, the water has nowhere to go. It builds up inside the frame until it reaches a level where it can spill over the internal lip of the door and onto your carpet or laminate flooring. If you've ever found a mysterious puddle on the floor after a night of heavy rain, the drainage holes are the first place you should look. It's rarely a broken frame; it's usually just a clogged pipe.
How to give them a quick clean
You don't need a professional to fix this. It's actually a pretty easy Sunday morning job. First, open the door and grab a vacuum cleaner. Use the thin nozzle attachment to suck out any loose debris from the bottom track.
Next, take a small piece of flexible wire—something like an unbent paperclip or a thin zip tie works great—and gently poke it into the holes. You're just trying to break up any compacted dirt. After that, take a jug of water and slowly pour it into the internal track. If everything is working as it should, you'll see the water trickling out of the external holes onto the sill within a second or two. If it just sits there, you've still got a blockage to deal with.
The mystery of the missing caps
If you've noticed that your drainage holes don't have those little plastic covers, it's not the end of the world, but it's worth getting some. Without them, heavy winds can actually push rain backwards through the drainage system. It sounds counterintuitive, but wind pressure can be strong enough to hold water inside the frame or even force it through to the inside of your house.
You can pick up a pack of these caps for a couple of quid online. Just make sure you measure the slot first, as there are a few different sizes. They just snap into place, and they make the whole door look a lot more finished.
Dealing with "concealed" drainage
If you've looked all over the front of your door and can't find any holes, don't panic. You probably have the concealed version I mentioned earlier. In this setup, the holes are drilled through the very bottom of the frame, and the water exits directly onto the plastic or stone sill underneath.
To check these, you usually have to look at the underside of the door frame from a low angle. If you suspect these are blocked, the "jug of water" test is your best bet. If the water doesn't come out from under the frame, you might need to use a bit of compressed air to blow the blockage out, as getting a wire into those angles can be a bit of a nightmare.
Why you shouldn't drill your own
If you discover your door doesn't seem to have drainage holes, your first instinct might be to grab a drill. Stop right there. uPVC frames are full of different chambers, some of which are reinforced with steel. If you drill in the wrong spot, you could hit the metal reinforcement, which will eventually rust, or you could bypass the drainage chamber entirely and send water straight into the core of the door.
If you really think your door was made without them, it's better to call out a window specialist. They'll know exactly which chamber needs to be tapped into to ensure the water goes where it's supposed to go without ruining the structural integrity of the frame.
Wrapping it up
Keeping an eye on where should drainage holes be on uPVC door frame is just one of those "adulting" tasks that saves you a lot of grief in the long run. It's a simple system, but it's vital for keeping your home dry. A quick check once a year—usually before the autumn rains start—is all it takes to make sure your door is doing its job.
Just remember: internal holes in the track, external holes (usually with caps) on the face or bottom, and keep them clear of gunk. If you do that, you'll never have to worry about the "slosh" or the damp patches on the rug again.