A tonneau cover is a protective cover that goes over the bed of your pickup truck. Tonneau covers come in different styles like folding, retractable, roll-up, snap, and hinged.
The main benefits of adding a tonneau cover include:
- Increased cargo security – The cover encloses the truck bed to protect your gear from theft or weather.
- Improved gas mileage – By covering the bed, it reduces air drag to improve fuel efficiency.
- Enhanced appearance – Tonneau covers provide a smooth, stylish look compared to an open truck bed.
- Extra storage space – Some covers convert into a cargo area for hauling extra items.
So if you want to safely haul cargo, tools, camping gear or other equipment in your truck bed while improving its look and gas mileage, a tonneau cover is an excellent accessory.
What types of truck bed liners are available?
The most common truck bed liner options are:
Spray-On Liners
- Made by spraying a coat of durable polyurethane/polyurea blend onto the bed
- Provides a seamless, uniform coating that bonds to metal
- Offers great impact protection against dents and scratches
Drop-In Liners
- Custom-fit, removable plastic liners that drop into the bed
- Protects from damage and can be easily replaced
- Come as a single sheet or with separate tailgate liner
Under Rail Bed Liners
- Thin, low-profile liners attached under bed rails
- Sits flush against bed without reducing depth
- Less invasive and lighter than other options
Over Rail Bed Liners
- Thicker plastic liners that sit atop bed rails
- Function similar to drop-in liners but with added protection
- Require more installation work
Can you put a tonneau cover on with these different bed liner types?
Yes, you can install a tonneau cover on a truck that already has a bed liner in place. The exact steps will vary somewhat based on the type of liner you have.
Is it possible with a spray-on bed liner?
A spray-on liner will not interfere with tonneau cover installation in most cases. Since this type of liner coats the entire bed uniformly, it generally won’t cause any fit issues or need modifications for the cover.
You can install the cover rails and mount them directly on top of the spray-on liner surface. It creates a protective barrier between the metal truck bed and cover components.
Overall, a spray-in liner is the simplest option for adding a tonneau later on.
What about with under rail bed liners?
An under rail bed liner attaches flush under the bed rails, leaving the top open. This also allows for straightforward mounting of a tonneau cover.
You can place the cover rails directly onto the truck’s bed rails and clamp them down without the liner getting in the way. Under rail liners provide protection underneath while the cover shields the top.
Is it possible with over the rail bed liners?
It’s more work, but definitely possible to add a tonneau with an over the rail liner. This type sits on top of the bed rails like a drop-in liner.
You’ll need to carefully check the clearance between the liner and underside of the cover. Some trimming and adjusting of the liner may be required.
It’s best to follow the recommendations from both the liner and cover manufacturer for optimal compatibility. Allow extra time for proper installation.
How about with drop-in truck bed liners?
As with over the rail liners, you can mount a tonneau cover with a drop-in liner but it requires some additional steps.
You’ll need to cut openings in the drop-in liner to allow the cover rails to securely attach to the bed. This may require drilling or slicing through the liner material with a utility knife.
Some tonneau cover kits come with pre-cut templates to follow for removing sections of the drop-in liner. Careful measurements and liner trimming will provide a clean installation.
What are the main steps to install a tonneau with a bed liner?
The basic installation process will be:
Clean truck bed
Thoroughly clean and dry the bed liner surface where cover will attach. Remove any dirt or debris.
Position rails
Place tonneau cover rails onto truck bed in the correct spots. For under rail liners, set directly on bed surface. With over the rail types, set on liner or use provided templates.
Attach rails
Clamp rails down and attach them at marked locations with provided hardware. Drill through liner if needed for bolts.
Adjust alignment
Check cover is centred and rails are evenly aligned. Make any necessary liner trims or adjustments.
Install seals
Apply any weather seals provided along the cover edges, tailgate, or cab side.
Secure cover
Roll or unfold cover onto the rails and secure it with clamps. Rotate unlocking levers to closed position if included.
Check operation
Test that cover opens, closes, and latches properly. Adjust fit if needed before finalizing install.
The manufacturer instructions will provide complete details for your specific truck, bed liner and tonneau model combination. Taking time to carefully follow the steps will ensure optimal fit and function.
What tonneau cover types work best with bed liners?
While most tonneau covers are compatible, here are some good options for trucks with liners:
- Retractable – Roll-up vinyl covers are adaptable to different bed surfaces and heights. No rails to install makes them simpler to fit over liners.
- Folding – Hinged panels adjust to fit different bed profiles. Perimeter seals help create a tight fit over the liner.
- Snap-on – Individual sections securely snap onto rails. Allows for conforming to liner surface variations.
- Truck bed caps – Fiberglass lids create an airtight seal. Can be custom trimmed at edges to account for thicker liners.
Softer vinyl covers with adjustable mounting rails provide the easiest fit. Low profile covers are also a good match for minimal liner interference.
What precautions should you keep in mind?
When installing any aftermarket truck accessory like a tonneau, it’s smart to take some preventative measures.
- Carefully read manufacturer instructions for both liner and cover. Follow all steps.
- Have help lifting and positioning the cover. They can be awkward and heavy.
- Allow plenty of time for adjustments to get the right fit over the liner.
- Use painter’s tape to mark cut lines and prevent scratches if trimming a liner.
- Apply rust inhibitor to any drill holes made in the truck bed.
- Periodically check clamps and mounting hardware; retighten if necessary.
- Make sure the cover gets mounted evenly to open, close and seal correctly.
With proper prep and installation, your truck can have a great looking and highly functional tonneau cover along with the protective bed liner. Take the time to do it right, and you’ll enjoy the added utility and style they provide.
Final Thoughts
Installing a tonneau cover on a truck with an existing bed liner is possible for most pickup models. Over-the-rail liners may require some trimming or adjustment to accommodate cover mounting rails. It’s always smart to consult manufacturer guidelines for the specific products you are installing.
With care taken during the process, you can have the best of both worlds – a truck bed shielded from dents and damage by the liner and cargo protected from weather and theft under the tonneau cover. This combination enhances your truck’s appearance while providing maximum utility.
