6 Best Skylight Repair Kits for Apartment Leaks to Save Without Sacrifice
Stop apartment skylight leaks affordably. Our guide reviews the 6 best DIY repair kits for a durable seal, helping you save without sacrificing quality.
Nothing ruins a cozy afternoon in your apartment faster than the slow, steady drip… drip… drip from a skylight. That single drop of water is a warning sign of bigger problems to come, from water stains to serious structural damage. But calling in a professional can be costly and slow, especially when you need a fix now. The good news is that with the right product and a little know-how, you can tackle most common skylight leaks yourself, saving a ton of money without sacrificing a dry, comfortable home.
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Pinpointing Your Apartment Skylight Leak Source
The first thing to understand is that the drip is rarely the source. Water is sneaky. It can travel along framing, under roofing material, and pop out feet away from where it got in.
Before you buy any product, you need to play detective. Start inside by noting exactly where the water is appearing. Then, if you have safe access, head to the roof. Look for the obvious culprits first: cracked sealant around the glass, gaps in the metal flashing that surrounds the skylight frame, or visible cracks in the skylight dome itself. Pay close attention to the "uphill" side of the skylight, as this is where water pools and finds its way in.
If the source isn’t obvious, you’ll need a helper and a garden hose for a controlled water test. Have one person inside watching for drips while the other person outside gently soaks specific areas one at a time. Start at the bottom of the skylight and work your way up, isolating the flashing, then the seal, then the glass. When the drip starts inside, you’ve found your entry point.
EternaBond RoofSeal Tape: The Permanent Fix
EternaBond RoofSeal tape creates a durable, waterproof seal on roofs, RVs, and more. Its MicroSealant technology bonds to various surfaces, offering UV resistance and eliminating the need for extra sealants.
When you want a repair that’s as close to "one and done" as you can get, EternaBond is the answer. This isn’t just tape; it’s a microsealant laminated to a UV-stable backing. Once it’s on, it’s on for good. The bond it creates is permanent and waterproof, fusing to almost any surface.
Its real strength lies in sealing long, straight seams or cracks. Think of a long split in the metal flashing or a failure along the seam where the skylight frame meets the roofing material. Application is straightforward: clean the surface meticulously, lay the tape down, and use a small roller or even the back of a spoon to apply heavy pressure. This pressure activates the microsealant, creating an instant, watertight seal. No waiting for anything to cure.
Flex Seal Liquid: For Complex Seam Repairs
Flex Seal Liquid creates a watertight barrier to stop leaks fast. This easy-to-use liquid rubber sealant seeps into cracks and remains flexible for long-lasting protection on roofs, basements, and more.
Flex Seal Liquid is a different tool for a different job. Where tape excels at covering straight lines, this thick, paintable liquid rubber excels at conforming to awkward shapes and complex joints. It seeps into tiny cracks and gaps, creating a seamless, flexible rubberized coating.
Imagine the corners of your skylight where multiple pieces of flashing meet, or the area around mounting bolts and hardware. These are places where tape can be difficult to apply without wrinkles or gaps. Flex Seal Liquid can be painted on, covering everything in a continuous membrane. The tradeoff is time. It requires a thoroughly clean and dry surface and needs several hours, or even days, to cure fully. This makes it a planned repair, not an emergency fix.
Dicor Lap Sealant: Pro-Grade Flexible Seal
If you’ve ever been around RVs or mobile homes, you’ve seen Dicor Lap Sealant. It’s the industry standard for sealing roof fixtures, and it works brilliantly for apartment skylights. This is a self-leveling sealant, which means you apply a bead and it slowly flattens out, or "laps," over the surface, creating a smooth, wide, and incredibly durable seal.
Its primary job is to seal the perimeter of the skylight frame and cover any screws or fasteners holding it down. Because it remains flexible after curing, it won’t crack or pull away as the roof expands and contracts with temperature changes. Crucially, this is for horizontal surfaces only. Its self-leveling properties mean it will run and drip if you try to use it on a vertical or steeply sloped surface.
Gorilla Waterproof Tape: Quick Emergency Patch
Think of this as the first aid kit for your skylight leak. A storm is rolling in, you’ve just discovered a drip, and you have no time for a proper repair. This is when you reach for Gorilla Waterproof Patch & Seal Tape. It’s thick, incredibly sticky, and can be applied in damp conditions to stop a leak in its tracks.
This is not your permanent solution. While it’s impressively strong, it’s best viewed as a temporary patch that buys you time. Use it to cover a crack or a failing seam to get you through the bad weather. Once things dry out, you can perform a more lasting repair with a product like EternaBond or Dicor, often right over the top of the temporary Gorilla Tape patch.
Sashco Through The Roof for Wet Surfaces
Seal roof leaks effectively with Sashco Through The Roof Sealant. This clear, 10.5 oz cartridge adheres to wet surfaces for a water-tight repair that lasts, even in freezing temperatures.
Sashco’s Through The Roof is a specialist sealant with a superpower: it sticks to wet surfaces. This is a game-changer for those emergency repairs that just can’t wait for a dry day. It’s a clear, co-polymer rubber sealant that forms an incredibly strong, elastic seal even when applied in the middle of a drizzle.
Unlike tapes, it’s a caulk-style sealant that can be tooled into tight gaps, cracks, and around complex shapes. Because it cures crystal clear, it’s a great option for patching a crack in the skylight’s acrylic dome itself without creating a huge eyesore. Its elasticity means it will stretch and move with the joint, preventing future cracks. When you absolutely have to fix a leak right now, rain or shine, this is the product you want.
Liquid Rubber Sealant: A Paint-On Solution
Waterproof and protect surfaces like roofs, planters, and foundations with this flexible, UV-stable sealant. The water-based formula is environmentally friendly and easy to apply indoors or outdoors.
Sometimes, a single leak is a symptom of a much larger problem, like widespread aging of all the seals around your skylight. In these cases, chasing individual drips is a losing battle. A paint-on liquid rubber sealant provides a comprehensive solution by creating a brand new, seamless waterproof membrane over the entire area.
The process is more involved, akin to a small painting project. You’ll need to thoroughly clean the skylight frame, flashing, and a border of the surrounding roof. Then, you apply several coats of the liquid rubber, often embedding a special reinforcing fabric between coats over seams and joints. The result is a thick, durable, and completely monolithic seal that covers all the old potential failure points. It’s a restoration, not just a repair.
Proper Skylight Sealant Application Steps
No matter which product you choose, its effectiveness comes down to proper application. Cutting corners here is the fastest way to find yourself dealing with the same leak a few months later. The fundamentals are always the same.
First, cleanliness is everything. You must remove every trace of old, cracked sealant, dirt, grime, and oils. A putty knife, wire brush, and a solvent like denatured alcohol are your best friends. The surface must be pristine for the new product to bond correctly.
This 4-piece stainless steel spackle knife set makes home repairs easy. Featuring comfortable, ergonomic handles and various blade sizes (2", 3", 4", 5"), these knives are ideal for applying putty, removing wallpaper, and more.
Second, ensure the surface is completely dry unless you are specifically using a product designed for wet application like Sashco Through The Roof. Trapped moisture is the enemy of a good seal. For tapes, this means a bone-dry surface. For most liquid sealants, it means waiting 24 hours after the last rain.
Finally, follow the product’s instructions to the letter. When using tape, apply firm, even pressure across the entire surface to activate the adhesive. For caulking, apply a consistent, generous bead and "tool" it with a wet finger or tool to press it into the seam. And most importantly, respect the cure times. Don’t expose a new liquid repair to a downpour before it’s ready.
Fixing a skylight leak doesn’t have to be an expensive, complicated ordeal. By correctly identifying the source and choosing the right tool for the job—whether it’s an emergency patch or a permanent seal—you can confidently solve the problem yourself. A little preparation and the right product will keep your apartment dry, protect your investment, and give you peace of mind the next time the rain clouds roll in.
