Exterior Bedroom Door Progress — Replacing Hardie Board Trim With Faux DIY Concrete Stones

I worked with them at the time to figure out the best solution, and this was the best we could come up with. I thought I could make do with it. I had convinced myself that I’d be satisfied with it once it was all painted. But the more I looked at it, the more I hated it.

It has Hardie board trim that’s kind of even with the stone facade, and that Hardie board trim wraps around the door jamb and meets the PVC trim that came on the prehung door. But one major issue is that we couldn’t put trim above the door to match. So the whole thing just looked awkward to me.

That door was installed eleven months ago, and I’ve been trying to figure out a solution ever since then. But since then, I did a very big concrete project on our front porch using concrete to create a faux stone facade for the porch skirting area to match the stone on the rest of our house.

I started by removing the Hardie board trim from the left side of the door just to see what I was working with. I expected to see the 2×4’s that had been used to frame the door, but I had forgotten that they had used 1/2-inch plywood on the door frame to build that area out a bit for the Hardie board to sit closer to the front of the stones.

Rather than remove those, I decided to keep them there, but I had a lot of gaps to fill and a lot of waterproofing to do before I could get to the fun part of this project. I used Great Stuff expanding foam to fill in the gaps.

I let it expand and cure for a few hours…

…and then I trimmed off the excess with a sharp serrated kitchen knife.

And then I went back over those areas, as well as the nail holes and any tiny cracks, with caulk.

When the caulk was dry, I did one more waterproofing step. I used my Semco liquid membrane…

And I brushed that onto the whole area, making sure that the wood, the remaining Hardie trim on the jamb, and all of the caulked areas were fully coated.

I did that extra step not only for waterproofing but also because I didn’t want to put concrete on any porous surface that would suck up the moisture from the concrete as it was curing. So this waterproofing membrane helped to keep the water in the concrete during the curing process rather than being wicked out into dry wood.

Next, I decided on my pattern for the faux stones. I wanted some of the new faux stones to be a continuation of the original stones, while I wanted others to be separate, individual stones. In other words, I didn’t want the finished door to look like I had just added a series of five-inch stones around the door. So I decided which original stones I wanted to continue around the door, and I used my handheld grinder to grind about two inches of the face of those stones so that I could get down to bare stone. The stone on our house is painted, and I couldn’t add concrete on top of paint. So I needed to expose the bare stone to give it some “tooth” so that the new concrete would adhere to it.

You can tell by the color which ones I ground down with my handheld grinder. The paint on our house is gray, so these off-white areas are the areas that I ground down.

Next, I needed to attach some galvanized diamond mesh lath over the areas where I wanted to put the concrete. Without this, there was no chance that the concrete would hold. I found this in the concrete section of my local Home Depot. It comes in a 27″ x 96″ piece, so I had to use my tin snips to cut off the size I needed, which was 7″ x 89.5″.

And then I used 2″ exterior screws to screw the lath onto the area. I made sure to completely cover all of the wood and the Hardie trim, wrapping it around to meet the PVC trim on the prehung door.

After getting that lath on the whole area, I went back and added more screws in any areas where it wasn’t lying flat against the wood. If it looked like it was bowing out or had any give to it, I added a screw.

With the lath on, I was finally ready to mix some concrete. I used Rapid Set Cement All for this project, which is the same thing I used to pour the faux stones for the front porch. I really like Cement All because it uses a really fine sand as the aggregate, so it can be feathered out to a really fine edge, which was important for creating the stones. But I used it for my scratch coat as well. Using a 6″ x 2″ trowel, I covered the lath with the concrete, making sure that I pushed the concrete into the lath really well. I wasn’t concerned about how this scratch coat looked. In fact, the rougher, the better. The roughness gives the next coat (i.e., the faux stones) something to grab onto.

Here’s a closer look at that scratch coat. You can see that before I added the concrete, I put painters tape on the white PVC door trim to protect it from the concrete and to give myself a clear visual of where my “stones” needed to stop.

I started at the bottom and worked my way up. I did this because I really had no idea what I was doing and I was fairly certain that I’d need to do a few stones before I felt comfortable with the process. So if I messed up on the first couple of stones, those could eventually be hidden behind some pretty planters. 😀 And sure enough, my first “stone” looked ridiculous. All I could see was some sort of smiling Jabba the Hutt face looking back at me. But because the concrete sets up so fast, there was no getting rid of that face. (I did go back with my grinder and reshape it later.) The second “stone” was better, but still not great. Again, I waited too long to try to texture it, and by then (literally within ten minutes), it was too hard to get it just right.

By the third stone, I was getting my process and technique down much better. I’ll still go back and fix some of the weird parts with my grinder before painting these faux stones, though.

And while I do want to fix some areas with my grinder now that these are cured, I’m very pleased overall with how this is looking. I think this is going to look so much better than that awkward Hardie trim around the door!