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That six-inch gap on each side of your truck mattress is a real pain. It swallows pillows, drops phone chargers, and makes your whole sleeping setup feel unfinished.
I have battled these gaps in my own truck for years. The secret is that a simple pool noodle or a tightly rolled sleeping bag can often fill that space better than expensive custom inserts.
Fill That 6-Inch Gap Now
That six-inch gap on each side of your wheel wells makes standard truck mattresses useless. You end up with your arm or gear falling into the void all night. The Designs International 5.5″ Thick Foam Mobile Mattress Semi is cut specifically to wrap around wheel wells, so the foam sits flush against your truck bed walls.
Grab the mattress that actually fits around wheel wells without leaving gaps: Designs International 5.5″ Thick Foam Mobile Mattress Semi
- Luxury Mattress conforms to the shape of your body, promoting healthy, restful...
- Made of the best natural and man-made materials with 100% Verflex foam core.
- Hypoallergenic and environmentally safe.
Why Those Gaps Ruin a Good Night’s Sleep
I learned the hard way that a gap is not just annoying. It is a safety hazard when you roll over in the dark.
Last summer, my son was sleeping on the passenger side of my truck bed. He rolled right into that six-inch gap and hit the metal wheel well hard. He woke up crying, and our whole camping trip started on the wrong foot.
How a Small Gap Creates Big Problems
That gap does more than just steal your pillow. It lets cold air rush up from the truck bed, making one side of your body freezing.
In my experience, that cold draft wakes you up every two hours. You spend the night fighting for space instead of actually resting.
The Real Cost of Ignoring the Space
Before I fixed my gaps, I wasted money on expensive mattress toppers that did not help. They just slid into the hole and left me with a lumpy mess.
Here is what I now know about those six-inch gaps:
- They create a tripping hazard when you get up to pee at night
- They let dirt and leaves collect under your bedding
- They make your truck bed feel smaller than it actually is
Fixing this one issue changed my whole camping experience. I stopped dreading bedtime and started looking forward to it.
My Best Solutions for Filling Truck Bed Gaps
After that rough night with my son, I tried everything to fix those gaps. I learned that you do not need fancy gear to get a flat sleeping surface.
The Simple Pool Noodle Trick
Honestly, this is what worked for us on a budget. I bought two standard pool noodles and cut them to the exact length of my truck bed.
I wedged each noodle tightly between the mattress edge and the wheel well. They are cheap, waterproof, and easy to replace when they get dirty.
Why Foam Blocks Work Better Long Term
Pool noodles are great for a quick fix. But they flatten out after a few trips and need replacing.
For a permanent solution, I cut upholstery foam blocks to match the gap size. I wrapped them in an old pillowcase so they would not slide around.
What I Use for My Kids Now
My kids toss and turn all night, so I needed something tougher. I found that a rolled-up camping blanket stuffed into the gap works perfectly for their side.
I secure it with a bungee cord hooked to the truck bed tie-downs. It stays put even when my youngest thrashes around in his sleep.
You know that sinking feeling when you hear your child cry out because they fell into a cold metal gap in the dark? I got tired of that worry ruining my trips, so I grabbed what finally worked for our family and never looked back.
- About our Foam: Our foam is certified for suitability. Our foam features are...
- Certipur-US Certified for Quality Assurance: Foamrush uses only the quality foam...
- Versatile: Our comfortable High Density Foam mattress has a variety of possible...
What I Look for When Buying Gap Fillers for My Truck
After trying cheap tricks and store-bought options, I learned what actually matters. Here is what I check before spending any money.
It Must Stay Put Without Glue
I do not want anything permanent in my truck bed. I need a filler that stays in place when I drive but comes out easily for cleaning.
My first attempt slid all over the place. Now I only buy options with a non-slip backing or a snug friction fit.
Water Resistance Is Not Optional
Your truck bed gets wet. Rain, morning dew, and spilled drinks will ruin a cheap foam filler in one season.
I look for closed-cell foam or waterproof covers. A soggy gap filler smells awful and grows mold fast.
Easy Removal for Hauling Gear
Sometimes I need my full truck bed for lumber or furniture. I need gap fillers that pop out in seconds.
I learned this the hard way when I had to wrestle with a stuck filler at the hardware store. Now I only buy ones with handles or flexible material.
Thickness That Matches My Mattress
A filler that is too low creates a new dip. One that is too high pushes your mattress up and makes you sleep at an angle.
Measure your mattress thickness first. I use a filler that is exactly one inch taller than my mattress for a perfect flat surface.
The Mistake I See People Make With Truck Bed Gaps
I see folks buy a giant mattress that covers the whole truck bed floor. They think a bigger mattress will just bridge over the wheel wells on its own.
That never works. The mattress just sinks into the gaps and creates a hammock effect. You end up sleeping in a U-shape with your back aching by morning.
Another common error is stuffing random blankets into the gap. Blankets compress overnight and leave you right back where you started.
I made this mistake on my first camping trip. I woke up at 3 AM with my arm wedged into the wheel well and my pillow gone. It was a miserable night.
You know that sinking feeling when you spend good money on a solution that fails by midnight? I got tired of waking up sore and frustrated, so I tried what my neighbor recommended for his own truck and finally got a flat sleep surface.
- 【3-Layer Structure】The mattress cover's upper and lower layers are filled...
- 【Temprorary Sleep Provider】 The cot mattress topper can be used on a cot or...
- 【Thickened Machine Washable Cover】The mattress cover has three side zippers...
The One Trick That Made My Truck Bed Feel Like a Real Bed
Here is the insight that changed everything for me. You do not need to fill the entire six-inch gap perfectly.
You just need to create a ramp from the mattress edge down to the truck floor. A gradual slope is way more comfortable than a hard block.
I cut a piece of firm foam into a wedge shape. The thick side sits against the mattress, and the thin side touches the wheel well.
This wedge keeps me from rolling into the gap. It also stops my pillows from disappearing overnight.
The best part is that a wedge takes up less storage space than a full block. I keep mine under the back seat when I am not camping.
Try this with any dense foam you have around the house. Cut it at a 45-degree angle and test it out before spending money on anything fancy.
I wish I had thought of this years ago. It saved me from buying multiple products that never quite worked right.
My Top Picks for Filling Those Truck Bed Gaps and Sleeping Flat
I have tested a few different mattresses in my truck over the years. Here are the two that actually solved my gap problem without breaking the bank.
FoamTouch 8 Inch Gel Memory Foam Mattress — Thick Enough to Bridge the Gaps
The FoamTouch 8 Inch Gel Memory Foam Mattress is thick and dense enough to span those six-inch gaps without sagging. I love that the gel keeps me cool on hot summer nights. It is perfect for side sleepers who need pressure relief, but it is heavy to move around solo.
- ✅ Proudly Made in the USA
- ✅ High Density Foam – Crafted with 1.8 LB density foam for superior support...
- ✅ Firm Support (44 ILD) – Ideal for RV bunk beds, mattresses, cushions, and...
Mytee Products 6.5 Inch RV Mattress 32×79 Luxury Foam — A Slimmer Fit for Tight Budgets
The Mytee Products 6.5 Inch RV Mattress 32×79 Luxury Foam is a great choice if you want something lighter and easier to store. I like how it fits snugly between the wheel wells without sliding around. Just know that it is thinner, so you may still need a small filler for the gaps.
- Mobile Luxury Mattress 6.5" Gray Pinstripe, Quilted Both Side
- Sizes: 32" W x 79" Long x 6.5" Thick
- Breathable Quilted Cover and Compatible with most Truck Bunks
Conclusion
The best way to handle those six-inch gaps is to fill them with something firm that matches your mattress height and stays put overnight.
Go measure your truck bed and mattress thickness right now. Grab a pool noodle or a scrap of foam and test a wedge shape before your next trip.
Frequently Asked Questions about How Do I Handle a 6-Inch Gap on Each Side from Wheel Wells with My Truck Mattress?
Can I just use a bigger mattress to cover the wheel well gaps?
I tried this myself and it did not work well. A bigger mattress just sinks into the gaps and creates a hammock effect that hurts your back.
You are better off keeping a properly sized mattress and filling the gaps separately. That gives you a flat surface without wasting money on an oversized mattress.
What is the best material to fill a six-inch truck bed gap?
In my experience, closed-cell foam works better than anything else. It does not soak up water and it holds its shape after repeated use.
Pool noodles are a cheap starting point. But for long-term comfort, I recommend dense upholstery foam cut to fit your exact gap size.
Will a pool noodle stay in place while I drive on rough roads?
A single pool noodle will slide around on bumpy roads. I learned this the hard way when mine ended up near the tailgate after a gravel road.
You can fix this by wedging the noodle tightly or securing it with a bungee cord. I also wrap mine in a non-slip shelf liner for extra grip.
How do I keep my mattress from sliding into the gap at night?
This happens when your filler is too soft or too short. I had this problem until I switched to a filler that was one inch taller than my mattress.
You can also place a non-slip mat under your mattress. That keeps everything in place even when you toss and turn during the night.
Which truck mattress won’t let me down when I need a flat surface for side sleeping?
If you are a side sleeper like me, you need a mattress with enough thickness to bridge the wheel wells without sagging. The FoamTouch 8 Inch Gel Memory Foam Mattress gives me the support I need without any dip into the gaps.
I appreciate that the gel layer keeps me cool all night. It is the what finally worked for my own truck setup after trying thinner options that failed.
- ✅ Proudly Made in the USA
- ✅ High Density Foam – Crafted with 1.8 LB density foam for superior support...
- ✅ Firm Support (44 ILD) – Ideal for RV bunk beds, mattresses, cushions, and...
What is the most affordable way to fix wheel well gaps for a weekend camper?
For someone who only camps a few times a year, you do not need expensive gear. A rolled-up sleeping bag or a couple of pool noodles will get the job done for cheap.
If you want something that lasts longer without breaking the bank, the Mytee Products 6.5 Inch RV Mattress is a solid choice. It is what I grabbed for my kids when they started camping with me regularly.
- Size for RV Bunk Beds: This mattress topper measures 80" ×72" × 2"; It is...
- Relieve Stress: This RV mattress topper features a 2-inch-thick layer of memory...
- Breathable & Comfortable Design: The open-cell foam structure allows air to...