Love them or hate them, to maximize living area, most RVs will have slide-outs.
Our first motorhome had 3 slide-outs. When extended, they gave us the feeling of living in a small apartment. The living room had a slide on each side creating a huge space. And the bedroom had a single slide-out.
We bought the motorhome used. It was our first RV and we didn’t know exactly what to check. Unfortunately, it had major issues, including leaking slider seals in the bedroom.
Our current travel trailer has one super-slide. It gives us plenty of room to move around without feeling like we’re crawling over each other.
To be honest, we have a love/hate relationship with RV’s slide-out.
We love them because they expand our living area. But we hate them because they have problems.
Maintaining RV slide-out seals is quick and easy. And regular maintenance can extend their life by years.
Let’s start with the basics.
What Are RV Slide-Out Seals?
If you are new to RVing, you may not know what a slide-out seal is and what it does. We didn’t know anything about them when we bought our first motorhome.
Slide-out seals are giant rubber gaskets. Some people think it's a single seal, but it's actually two seals: an inner and an out seal. The inner seal keeps the heated or cooled air inside the RV. The outer seal keeps the rain and wind out and acts like a squeegee when pulling the slider in.
Without routine maintenance, slider seals will dry out and fail.
How To Tell If An RV Seals At Risk
The first indicator of dry seals is they crackle when pulling them in. If you hear it, the seals are dry and need immediate treatment.
With our first RV, the previous owner didn't maintain the seals. On our first trip, the sliders crackled and popped when we extended them.
When we checked the seals they were in bad shape. The inner seals were dry and cracked. The outer seals were worse. They folded in on themselves when we started retracting them. If it had rained, the squeegee action of the outer seals would have been minimal at best.
TIP: When buying a used RV with slide-outs, inspect the slider seals. They are a good indicator of good or bad maintenance. Conditioned seals will be black without cracks. Dry seals will look dull, and grayish and may have cracks. Don’t depend upon color alone because baby powder can make the seals look dull. Extend the slider then pull it back in. If the seals are dry, they’ll crackle or pop. And dry outer seals will fold in on themselves. Also, check the sides of the slide-out for black lines to see if the seals have dried against the side of the slider. These are all signs the poor seal maintenance.
Slide-Out Seals Maintenance
We camp in the high deserts of Nevada. The air is dry and temperatures range from the low 100s to below zero. So rubber dries out faster than it will in a more humid area with moderate temperatures.
Slider seals need cleaning and conditioning twice a year. We service our RV seals in the spring and fall. In the summer we recoat the sliders with baby powder to keep them working
TIP: Inspect the seals before your first outing in the spring. Recheck them after the last trip in the fall.
Servicing The Inner Seals
The outer seals protect the inner seal so they don’t need a lot of cleaning. Here’s step-by-step how we service the inner seals:
Things you need to service the slide-out inner seals
3 old socks A spray bottle of water RV seal conditioner (works on the interior and outer seals) Baby powder
Amount of time required to service the slide-out inner seals: 5 minutes per slide-out.
Retract the slider so you have access to the inner seal
As much as possible inspect the seals. You want to check the condition of the seals for cracks, tears, or evidence of binding.
- Dampen one of the socks then wash off the gaskets. There’s no need to scrub the seals. Remove any loose dirt and debris. There shouldn’t be much if the outer seals are working.
- Using a second sock, dampen it with a rubber seal conditioner. Run the dampened sock over the seals to condition them. No need to overdo it because a small amount of conditioner goes a long way. A can of conditioner will last us several years.
- Wait for the seals to feel dry. If you didn’t apply too much seal conditioner this should only take a few minutes.
- Apply a small amount of baby powder to the third sock then run it over the inner seal. You only want to apply a thin layer of powder so that the slider seals don’t stick to the RV.
Servicing The Outer Seals
Unlike the inner seal, the outer seal will be dirty and dusty. So they will need washing.
Things you need to clean the slide-out outer seals
2 old socks (reuse the socks for cleaning the inner seals) A ladder A bucket of soapy water A washing brush with an extension A spray hose RV seal conditioner Baby powder
Allow 20 minutes to service the slider outer seals.
Extend the slider
- Inspect the outer seals for cracks or damage. Don’t forget to look at the seals beneath the slide-out.
- Use soap and water to wash the seals. If you have a topper on the slide-out, you can use a brush with the extension to clean the seals. While washing the seals, this is a good time to wash the top and sides of the slide-out. You want the sides and tops clean and smooth so the outer seal can squeegee off any water.
- Use the spray hose to rinse off the soapy water
- Wait for the seals to dry
- Use the same sock from conditioning the inner seals to condition the outer seals
- Use the same sock from applying baby powder to the inner seals to apply powder to the outer seals
TIP: Our super slider is too long for us to reach past a quarter of its length. We attach the conditioning sock to a painter's extension so we can reach the halfway point. We then move the ladder and do the other half. We do the same thing when applying the baby powder.
When cleaned, the slide-out seals will have a dull look to them. This is because of the baby powder. Run the slider in and out a couple of times. If the outer seal doesn’t glide along the side of the slider, find out why. Make sure the sides of the slider are clean and smooth. If there is tree sap or other debris on the side, remove it then retest. If the sides are smooth but the seals seem to bind, apply some more baby powder to the seal and retest.
Slide-out seal maintenance is often overlooked. But taking time to maintain them will add years of use and save you money.