How To Install Doorway Molding

Ever walk into a room and feel like something is just…missing? Often, that missing piece is the subtle but impactful finishing touch of doorway molding. Beyond simply framing an entrance, doorway molding adds character, definition, and a touch of elegance that elevates the entire space. It can conceal imperfections, bridge the gap between the wall and the door frame, and create a seamless transition from one room to another. Neglecting this detail can leave your home feeling unfinished and lacking the warmth and sophistication it deserves.

Properly installed doorway molding not only enhances aesthetics but also protects your door frame from everyday wear and tear. Think of it as a stylish shield against bumps, scratches, and the general chaos of a busy household. Whether you're a seasoned DIY enthusiast or a beginner looking to tackle your first home improvement project, mastering the art of doorway molding installation is a valuable skill that will pay dividends in the beauty and longevity of your home.

Ready to get started? What tools will I need, and how do I cut those tricky angles?

What's the best way to cope doorway molding for inside corners?

The best way to cope doorway molding for inside corners is to use a coping saw to remove the back portion of the molding along the profile of its face, allowing it to precisely match the contour of the adjoining piece. This creates a tight, virtually seamless joint that hides any imperfections in the corner itself and accommodates slight variations in wall angles better than a mitered joint.

When coping, begin by cutting the first piece of molding square and installing it flush against one wall of the inside corner. This piece acts as your "template." Next, cut the second piece of molding square as if you were going to miter it for the same corner, but instead of installing it directly, use a coping saw to carefully remove the material along the back edge, following the profile of the molding's front face. The key is to angle the saw slightly backward as you cut, creating a slight back-cut that will ensure the face of the coped piece sits flush against the installed piece. Coping offers several advantages over mitering. Inside corners are rarely perfectly 90 degrees, and even slight variations can cause mitered joints to open up over time as the wood expands and contracts. Coping, however, allows for a more forgiving fit, as the profile of the coped piece conforms to the existing molding, concealing any minor gaps. It also prevents unsightly gaps from forming as the house settles, making it the preferred method for achieving professional-looking, long-lasting inside corner joints with doorway molding.

How do I measure accurately to ensure tight-fitting mitered corners?

Accurate measurement is crucial for tight mitered corners. Measure each side of the doorway opening precisely at the point where the molding will sit, then subtract the amount of the miter cut from each measurement. This accounts for the portion of the molding that will be removed by the mitered cut. Use a high-quality measuring tape and double-check all measurements before cutting.

To elaborate, remember that interior doorways are rarely perfectly square. Taking multiple measurements along each side, particularly at the top, middle, and bottom, will help you identify any inconsistencies. Use the smallest measurement found on each side as your basis for cutting. It's often better to slightly undersize the molding and then use caulk to fill any small gaps than to cut it too long, which will prevent the molding from fitting properly. This is especially true for mitered corners, where even a slight error can create a noticeable gap.

Furthermore, investing in a good quality miter saw with a sharp blade is critical. A dull blade can cause the wood to splinter and chip, making it difficult to achieve a clean, tight miter joint. When cutting, always err on the side of caution and cut slightly long. You can then fine-tune the fit with a block plane or sanding block. It's far easier to remove a small amount of material than to add it back.

Also, remember this list for ensuring an accurate cut:

What type of nails or fasteners should I use for doorway molding?

For installing doorway molding, 1 1/4-inch to 2-inch long finish nails or brad nails are generally recommended. The specific length depends on the thickness of your molding and the material behind it (wall studs, drywall, etc.). These nails are thin enough to minimize splitting the wood and leave a small, easily filled hole.

The choice between finish nails and brad nails often comes down to personal preference and the tools you have available. A finish nailer typically uses 15 or 16 gauge nails and provides a slightly stronger hold than a brad nailer, which uses 18 gauge nails. For heavier or more intricate molding, finish nails are usually the better choice. Brad nails are suitable for lighter moldings or when you want to minimize the appearance of the nail holes, especially if you're planning to paint the molding. Consider the substrate you're nailing into as well. If you're nailing into solid wood framing, the holding power of the nail is less critical. However, if you are primarily attaching the molding to drywall or plaster, longer nails that can reach the studs behind the wall are essential. If you can't reliably hit studs, consider using construction adhesive in conjunction with the nails for a more secure bond. A combination of adhesive and nails will prevent the molding from pulling away from the wall over time, especially in high-traffic areas.

How do I deal with uneven walls or door frames when installing molding?

When installing doorway molding with uneven walls or door frames, the key is to scribe, shim, or caulk to compensate for the imperfections. Scribing involves carefully tracing the contour of the wall onto the molding and then cutting away the excess material to achieve a perfect fit. Shimming fills gaps between the molding and the wall, while caulk provides a flexible seal to conceal minor inconsistencies.

Uneven walls are a common headache when installing molding. Before you even start cutting, use a level and a straight edge to identify the high and low spots. If the wall is only slightly uneven, you might be able to get away with using extra adhesive caulk to fill the gaps. However, for larger gaps, scribing is the best approach for a seamless look. To scribe, hold the molding tightly against the wall, following its contours. Use a compass or a profile gauge to transfer the wall's shape onto the molding. Then, carefully cut along the scribed line with a coping saw or jigsaw. Test the fit and make adjustments until the molding sits flush against the wall. Door frames can also be out of square or have inconsistent surfaces. Shims, thin pieces of wood, plastic or composite, are your best friend here. Slide shims behind the molding where it doesn't make contact with the frame, ensuring the molding sits level and plumb. Once the molding is securely attached, snap off the excess shims with a utility knife. For smaller gaps, paintable caulk can be used to create a smooth, finished appearance. Apply the caulk carefully and smooth it with a wet finger or a damp cloth. Remember to prime and paint the caulk after it has dried. Remember, patience is key; take your time to address the imperfections for a professional-looking result.

Should I prime and paint the molding before or after installation?

It's generally recommended to prime and paint the molding *before* installation. This is often referred to as pre-finishing and results in a more professional and efficient job, especially when dealing with intricate profiles or using spray equipment.

Pre-finishing your molding offers several advantages. First, it's much easier to apply an even coat of primer and paint on a flat, horizontal surface in a controlled environment like a workshop or garage. This minimizes drips, runs, and uneven coverage, particularly when using spray equipment. You can also easily sand between coats for a smoother finish. Trying to paint intricate molding already installed against a wall is significantly more difficult, requiring more masking and painstaking brushwork to avoid getting paint on the surrounding surfaces. Furthermore, pre-finishing helps prevent the raw wood from absorbing moisture, reducing the likelihood of warping or swelling after installation. While you will still need to fill nail holes and caulk seams after installation, touching up these small areas is much easier than painting the entire molding in place. The exception to this is if you are using a very dark paint color; painting after installation will ensure a consistent final look, as the filled nail holes will blend in more seamlessly. However, even in this case, priming beforehand is still advantageous.

What's the proper order to install the different pieces of doorway molding (e.g., head casing, side casing)?

The generally accepted order for installing doorway molding is to first install the side casings, then the head casing. This sequence allows the head casing to sit atop the side casings, creating a clean and professional finish where the horizontal and vertical pieces meet.

Starting with the side casings allows you to establish the vertical lines of the doorway first. Plumb each side casing carefully, ensuring it's perfectly vertical before securing it with nails or screws. Once the side casings are in place, you can accurately measure the space between them at the top. This measurement is crucial for cutting the head casing to the correct length. Ensuring the side casings are installed and plumb first makes for a tight fit for the head casing.

The head casing is then cut to fit snugly between the side casings. It should rest directly on top of the side casings. Depending on the style of molding, the head casing might have a decorative element that overhangs the side casings, further enhancing the visual appeal. By installing the head casing last, any minor discrepancies in the side casing height can be easily hidden, resulting in a more polished and professional-looking frame. Remember to use a combination square and miter saw for precise cuts.

How do I handle a doorway that isn't perfectly square?

Dealing with a doorway that's not perfectly square requires careful scribing, shimming, and caulking to ensure your molding looks professional and fits snugly. Don't assume everything is 90 degrees; measure each corner and account for any discrepancies. This might involve adjusting your miter saw angles slightly or using a coping saw for a more custom fit.

When a doorway is out of square, attempting to force perfectly cut molding into place will only highlight the imperfections and potentially damage the trim. Instead, focus on concealing the gaps and inconsistencies. For slightly out-of-square situations, you can often adjust your miter saw by a degree or two to create a tighter joint. For more severe cases, "scribing" the molding can be incredibly effective. This involves tracing the contour of the wall onto the back of the molding, then carefully removing material along that line with a coping saw or similar tool to create a custom fit. Shimming behind the molding is another essential technique. By inserting thin pieces of wood or plastic shims between the wall and the molding, you can subtly adjust its position to create a more visually appealing appearance and ensure even contact. Once the molding is secured, use paintable caulk to fill any remaining gaps between the molding and the wall or the molding and the door casing. Choose a high-quality caulk that can be painted over to seamlessly blend with the trim, resulting in a clean and professional finish that disguises any imperfections in the doorway's squareness.

And that's it! You've successfully installed your doorway molding. Hopefully, this guide made the process a little less daunting and a lot more rewarding. Thanks for following along, and be sure to check back soon for more DIY tips and tricks to help you transform your home!