How to replace the interior material of an RV entry door

Over the course of the 5 years we have been traveling in this 2018 Keystone Fuzion 429, we began to see more and more of these hairline cracks on the interior material of our entry doors.

When doing an internet search for others with a similar problem, there was some anecdotal claims that this is caused by the use of adhesive to bind this thin material to the Styrofoam-like material that fills the void between the exterior and interior panels.

No matter the original cause, it is definitely weakening the interior panel to the point where the material is bending and "caving in" around the lock/handle.

We are going to replace it.

Close-up views of the many, many cracks in the interior material.

This is the panel we selected.  It happened to be at Menard's but we saw similar panels at other home improvement centers.  The finish of the panel is very similar to what is on our doors and seems noticeably thicker.  Hopefully, that means "more durable".  Menards did have a thinner panel but it did not have the pebbled texture and we just didn't want thin.

This is where we fast-forward quite a bit.

In order to remove the interior door material, we removed the door from the RV.  There are 18 screws holding the door to the hinges.  The door isn't heavy but it sure helps to have another person to help.

Once off, we laid the door on a table, being careful to put a moving blanket under the door to prevent any scratches on the exterior.

Take off the door latch and lock.  Remove the window.  The outside part of the window frame is caulked to the outside of the door.  Ours was loose on one door and more stuck on the other.  We removed them either way because a) we wanted to re-caulk that window frame and b) it makes it easier when drawing the outline of the window you need to cut from the new material.

Bit by bit, we started removing the cracked interior material.  Slide a putty knife between the cracked material and the white Styrofoam-like filling.  You won't get a perfect separation but take your time.

On the hinge side of the door, you will notice a U-shaped piece of metal tucked under the black trim.  That's what gives the hinge screws something to bite into.  It also provides us with some challenges.  The first one here, the next one later.

The challenge here is that the interior door material is in between the black trim and a part of this metal.  Glued in.  You will need to run your putty knife on both sides of the door material to get it to start letting loose from the adhesive.  Pieces of the door material might break off as you try to pull it out.  You will need to get that channel cleared for when we put the new material in.

You likely have a little latch that holds your screen door to the entry door.  Behind that little latch is probably a piece of metal that gives the screws something to hold onto.  This may or may not come out cleanly.  I never liked the thin metal the factory uses for things like this so I threw this one away and made my own.

I wanted to make sure I got this part of the door latch reassembled correctly so I took some pictures.

Fast-forward quite a bit again.

We need to cut the panel to match the door.  Have your door on the table with the bare foam side up.  Lay your panel on top, good side up.

There are two ways to proceed here.  I prefer the second method because it reduces the amount of cutting.

First method:

Lay your new panel on top of the door so there is overlap all the way around.

Take a pencil and draw along the underside of the panel as it meets the outline of the door on the top, sides, and bottom.

You have now marked the OUTSIDE of that black trim that goes around.  Flip your panel over.  Since your panel has to be wedged inside and underneath that black trim, you need to cut INSIDE the line for the top and sides you just drew by 1/8" to 3/16".  I wouldn't go more than that.

Second method:

With your panel on the door, align one side and the top of your panel so that they match the outside edge of that black frame of the door on those sides.  Now slide your panel away from the side and away from the top so that you have the 1/8" to 3/16" "gap" between the outer edge of that side and top.  This will represent the amount you will be tucking inside the black frame of the door.  Now, take your pencil and draw underneath along the curves at the top and along the side where the panel is hanging over.  Draw along the bottom too.

Now, when you flip your panel over, the pencil mark along the side is the OUTSIDE edge of the door frame and you need to cut 1/8" to 3/16" INSIDE that line.  Be careful cutting the curves.

The first thing I did was cut the side and bottom off straight then laid the panel back on the door to double check that I got the amount of "underhang" on the sides and top but also to check how the curve will have to be cut.  Take your time and get it right.

Note about cutting the bottom:

Do not cut the bottom flush yet.  Leave an extra 4" or so on the bottom because you will be banging on that with a hammer and backing board to move the panel into place and you don't want to damage a nice edge.  You will cut that bottom off later.

The new panel we bought is thicker material than what was on the door from the factory.  This causes challenge number 2 on the hinge side.  Remember that piece of metal that the hinge screws go into?  It creates a parallel channel in which you need to push this new panel.  Since the panel is thicker, it just won't go.  I took a belt sander and sanded off along that edge on the SMOOTH side, not touching the pebbly side.  I sanded off a bevel that would go between those two pieces of metal.  Practice with a scrap piece of panel.  The pictures above, on a scrap trial piece, show what I'm talking about.

As if you haven't had enough fun yet, there is so much more.

Put your panel back up on your door on the table and start wedging the panel into the hinge side.  We had to use a hammer and a backing board to firmly but gently tap on the non-hinge side to push the hinge side in.  You may have to work top to bottom and back again to get it in there uniformly.  The top of your panel cannot be all the way to the top of the door because that needs to be under the black frame too, so just bring it down maybe 1" or so.

Once the hinge side is in, bow the middle of the panel up so the non-hinge side can get wedge into the door frame.

Once that's in, move down to the bottom of the door.  Using your backing board and hammer, start tapping (pounding!) the panel toward the top of the door.  As the edge approaches, your helper can start guiding the panel under the door frame.

It is a good idea to stick some painter's tape about 1/4" from the top of your panel, right in the middle, so you know how much you've shoved the panel under the frame.  Otherwise, you just can't really tell.

After getting the panel inserted, we flipped over the door and drew pencil marks where the window and door latch openings need to be.

The extra material at the bottom of the door has to be cut nearly flush with the extent of the frame.  I say "nearly flush" because it needs to be just a little "shy" of flush because the metal piece that goes across the bottom, and screws into the sides, needs a little room to overlap.

When putting the new panel on, you may notice that we never talked about using any kind of adhesive.  We did not.  Certainly, the window frame will securely hold the panel in place and, even though the area below the window is pretty large, we didn't feel the need to glue it to the foam.  The new panel material is rigid enough that we just didn't think we needed to secure it.

On the piece of the window frame that is on the outside of the door, there are two channels.

The outer channel, once filled with a bead of caulk, fits snugly and seals against the exterior door material.

The inner channel, once filled with a bead of caulk, seals the window snugly.

Screw on the interior side of the window frame to help pull the exterior side against the outside of the door.

We chose clear caulk that goes on white and cures clear.  You will have some of the caulk squish out so clean it up.

If you had a screen door latch just below your door handle, you will need to slide the original metal backing piece down between the new panel and the foam or make your own (which is what I did).

Then you can put your door handle back on.

The door is back on the RV.  Looks great!

So how long did it take us to do this?  We really took our time on the first door.  Probably parts of three days as we measured many times, figured out how to wedge the material into the channel on the hinge side, etc.  The second door could have been done in a single day, probably six hours or so.