Slideout Seals


If you own an RV with a slideout then you know the almost magical transformation that happens when it is deployed. Recreational Vehicles are not known for their sprawling square footage. Whether you’re a full-time RVer or a weekend warrior, every square foot counts. And boy do those slideouts make a difference. There is one potential drawback to a slideout, the fact that it slides-out through a giant hole in the sidewall. Let’s not even talk about potential mechanical failure in the slideout mechanism. Instead, let’s focus this article on preventing water intrusion through the biggest hole in the RV, the slideout joints.

I’m not even sure if “joint” is the best word to use to describe the intersection of slideout and RV sidewall. But you get the idea. There is an intersection, a point, and a penetration point where the slideout moves through the sidewall. You can’t have a zero clearance between the two. If you did, the slideout would never deploy, or both the slideout and the sidewall would be damaged every time the slide is extended or retracted. There is space, some wiggle room between the two. That space is the place where the greatest risk of water intrusion is.

‘What is done to mitigate the risk of water intrusion?” you ask. That is where the slideout seals come in. Sweep seals (sometimes called blade seals) are thin rubber piece that flaps out when a slideout is deployed. Bulb seals are typically the round seal that squished between the slideout and the sidewall when the slideout is retracted. These two types of seals are the primary defense against water intrusions in a recreational vehicle slideout. That is why we pay close attention to the slideout seals when conducting a Certified RV Inspection.

First, let’s talk about sweep seals. Those little rubber flaps do a lot to keep the water out. However, they can’t do their job if they are not properly deployed. The sweep seal it intended to flap out when the RV slideout is deployed. As an RV owner, you will do yourself a big favor by checking to make sure the sweep seals are all flapped out and laying against the side and top of the slideout. The sweep seal should make contact with the surface of the slideout wall and roof. That contact should be sufficient enough to prevent any water from going under or behind the sweep. That is when you know it has deployed properly. We’ll talk about caring for seals in a little while, but first, let’s talk about those other seals, the bulb seals.

Bulb seals are intended to be squished when the RV slideout is retracted. It squishes between the recreational vehicle sidewall and the slideout frame. That way any water that comes down on the RV from a rain storm will be forced to stay outside the recreational vehicle and not allowed to flow inside. We all know that water is probably the greatest enemy of recreational vehicles. When conducting Certified RV Inspections we make a point to look at anything and everything that could be a source of water instruction. These Certified Recreational Vehicle Inspections include evaluating the RV slideout seals.

So, how can we care for the RV slideout seals so they work the way they are supposed to and last a long time?

The answer is fairly straightforward. Clean them and protect them. “What are we protecting the seals from?” you may ask. The sun. The ultraviolet rays cause rubber-type materials to deteriorate faster. That is why you see (and we recommend) tire covers on recreational vehicles while they are parked. They are protecting the rubber tires from UV rays. You can both clean and protect your RV seals by using a product designed to clean and protect all in one application. We recommend Thetford Corporation 40015 Rubber Seal Treatment. You can get it on Amazon using this link

We also like 3-IN-ONE-120138-C RV Care Rubber Seal Conditioner.  You can get that one here

You may want to take one extra step if the seals are very dirty. If you spent time at Burning Man and have survived dust storms, then you will need to take this additional step first.

First, clean the RV slideout seals with water and a rag/cloth of some sort. Just get the surface dirt off. Next, spray the slide-out treatment onto a new clean cloth and wipe the inside and outside of the sweep seals and the outside of the bulb seals. It is recommended to do this once a month to maintain healthy seals. Of course, on top of that, you should periodically inspect the seals to ensure they have not been damaged in some way. That inspection can happen at the same time as cleaning and protecting. These small recurring steps will help keep your recreational vehicle.