How To Waterproof A Roof top Tent In 6 Steps

There’s nothing worse than waking up in your rooftop tent with wet blankets and a drenched pack. If you’re having issues with water getting into your rooftop tent, the fix can be as simple as re-applying a waterproof coating to the tent and rainfly.

To help you get started, we’ve put together this article on how to waterproof a rooftop tent in 6 steps. Here’s how to get the job done:

1. Troubleshoot where the leak is coming from.
2. Patch any holes in the tent with a patch kit.
3. Wash the tent with a tent detergent.
4. Seal the seams using a tent seam sealer.
5. Re-waterproof the underside of the rainfly using a urethane coating.
6. Re-waterproof the tent and outside of the rainfly using a durable water repellent.

In this article, we’ll take you through each of these steps in detail, providing step by step instructions and information on the products you should use. By the end, you’ll have all the knowledge you need to fix your waterproofing woes.

Step One: Figure Out Where the Tent Is Leaking

While you could just re-waterproof the whole tent to be on the safe side, it can be helpful to know exactly what’s causing the leak. Here’s how to do it:

1. Set up the tent as you would normally.
2. Inspect the tent for holes, wear and tear, or damage. Also check if the urethane coating is flaking.
3. Make it rain! Spray a nice gentle rain on the tent using a hose and have someone sit inside the tent to see where the water starts coming in first. This will show you the source of the leak.
4. Examine how the outside of the tent responds to the water. Does the water just soak through it, or does it bead up and roll off as it should?
5. Remove the rain fly and inspect it separately.

If you already know the source of the leak from your last waterlogged camping trip, then you can absolutely skip this step!

Step Two: Patch Any Holes in the Tent

If you happened to discover any holes, you’ll need to patch them using a tent fabric repair kit like the Tear-Aid Fabric Repair Kit. Read the instructions carefully and always listen to whatever the manufacturer says. Don’t worry, it’s not a challenging task. Here’s what you can expect: 

1. Clean the hole and surrounding area with alcohol.
2. Cut the patch to cover the hole plus an extra inch on all sides. Round off the edges of the patch.
3. Patch both sides of the fabric in any areas of high tension.
4. You should wait at least a day for the adhesive to dry before moving on to the next step.

Your tent should look like a pair of old blue jeans, but that’s okay. It just shows how loved it is!

Step Three: Wash the Tent

Before applying any waterproofing products, you need to wash the tent. This is a bit of a process, but it’s well worth it to have a nice clean tent and to ensure the waterproof products properly adhere to the tent fabric.

1. Lay the tent out on a table or a tarp where you can inspect it.
2. Spot-clean any heavily soiled places using a damp sponge and mild dish soap. Rubbing alcohol can be used to remove sap.
3. Fill a tub or large bin with warm water and add the appropriate amount of tent cleaner, like Nikwax Tech Wash. Tent-specific washes will not harm the delicate fabric of your tent or any waterproofing already in place.
4. Unzip the doors and windows and turn the tent inside out.
5. Place the tent (and the fly) into the soapy water and let it soak for the length of time suggested on the bottle of cleaner.
6. Rinse out the cleaner once it’s finished soaking.
7. Set the tent up outside to dry but leave it out of the sun. Some waterproof coatings require the tent to be damp for proper application. If this is the case, you don’t need to wait for the tent to dry before moving on to the next step.

Step Four: Seal the Seams

One of the most troublesome parts of a tent  is the seams. It’s easy for water to get through if they aren’t properly sealed. For best results, you’ll need to purchase a tent seam sealant like Gear Aid Seam Grip +WP.

1. Lay the dry tent out on a table, tarp, or any other clean place large enough for you to work on the seams.
2. Clean the seam with rubbing alcohol.
3. Squeeze some sealant along the seam and spread it out with a small paintbrush.
4. Allow the sealant to cure before moving on to the next step.

Make sure you purchase the right sealant to do the job. Most tents have some kind of polyurethane coating for waterproofing, but others may use different types of waterproofing. Read the information on the sealant’s box to be sure you’re purchasing one sealant that’s compatible with your specific tent.

Step Five: Re-Waterproof the Rainfly with Fresh Urethane Coating

Most rainflys have a urethane coating on their underside that provides superior waterproofing. Over time, this coating can degrade and flake off, which could cause your rainfly to lose its ability to keep water out of your tent.

You only need to do this step if you suspect the urethane coating has deteriorated or if there are visible signs of flaking.

Here’s how to get it done:

1. Lay the tent out on a flat surface that’s large enough to accommodate the area that needs recoating.
2. Scrub away the old coating using rubbing alcohol and the abrasive side of a sponge.
3. Apply a thin layer of tent sealant like the Gear Aid Tent Fabric Sealant.
4. Let the sealant dry for at least 24 hours before moving on to the next step or packing the rainfly away.

If your tent is leaking water through the urethane layer on the bottom, you can use the sealant to fix that as well!

Step Six: Re-Waterproof the Tent and Rainfly with a Durable Water Repellent

Now, for the important step of applying durable water repellent (DWR) to the outside of your tent and rainfly! This step is only necessary if water doesn’t bead up on the outside tent material. If water does bead up, the fabric’s waterproofing isn’t your problem, and another layer of durable water repellent won’t do anything.

You’ll need to purchase a DWR like Kiwi Camp Dry. Once again, you should read the manufacturer’s directions, but here’s an idea of what to expect.

1. Set up the tent and fly to ensure an even coating.
2. Your tent and rainfly should be damp for this step, so if it isn’t, you’ll need to break out a spray bottle and moisten it with some water.
3. Spray the DWR on to the tent and fly with an even coating of DWR.
4. Once you’ve applied the DWR, you can wipe off excess with a clean, damp cloth.
5. The tent and rainfly need to be completely dry before you pack it away.

And that’s it! Now you have a completely waterproof tent and rain fly that’s ready for the next adventure! The next time you take your rooftop tent out for a night under the stars, you won’t wake up with a face full of water.