Trim styles in homes will vary by taste and design. But, regardless of design choices, trim work installations should always be held to a high level of standards.

This article from The Honest Carpenter will show you how to identify quality trim work in a home. By focusing on five elements in particular, you will be able to “read” any trim installation like a pro carpenter!

The Right Tool for Quality Trim Work:

Miter Saw

12" miter saw

1. Returns

crown mould return in living room

Here the crown mould has been returned towards the cabinet face.

“Returns” are small pieces of trim that create a visible termination for a longer piece. Essentially, returns give the impression that the trim has turned a corner and vanished back into the wall.

For long pieces that actually do turn a corner or run into a wall, returns are not necessary. But, trim carpenters often encounter situations where a piece of trim cannot run into or “jump over” a certain areas. (Like in the picture above, where a stone facade interrupts the crown moulding.)

In these areas, carpenters cut the end of the longer piece at a 45 degree angle. After that, they cut a tiny piece at an opposite 45 degree angle. Finally, they glue and pin the two pieces together, so they create an finished outside corner of their own.

Why Are Returns Important in My Trim Work?

This effect is very visually pleasing.  Returns add an appearance of completion to the trim in a room. For trim as large and protrusive as crown moulding, returns are absolutely necessary to create a finished look.

However, it is also laborious and time-consuming to cut and install returns. So, for smaller pieces of trim, carpenters sometimes take a shortcut and simply “back miter” on the piece.

no return on trim chair mould

Back-miters are a weaker substitute for returns.

This is a cost-saving measure, and is actually extremely widespread and acceptable in residential construction. However, it reduces the aesthetic quality of trim in a room. For high-end trim work, returns should always be installed.

2. Scarf Joints

Scarf joints are a way of bringing two pieces of trim together so that they look like one long, continuous piece. On sections of wall longer than 12′ or 16′, scarf joints are utterly necessary. Why? Because lumber does not come in pieces beyond these lengths.

scarf joint in crown seam

Scarf joints should be smooth and unnoticeable–unlike this one!

In order to create a decent scarf joint, the two conjoining pieces should receive miter cuts in the same direction. This allows the pieces to “overlay” one another seamlessly when pushed together (pictured below).

scarf joint trim base board

Scarf joints cut, ready to install baseboard

Though relatively simple in concept, a smooth scarf joint can be hard to achieve. You often see bulges in the wall or ceiling, or twists in the trim lumber. These conditions can interfere with the joint, causing the two pieces to pry away from one another.

Well, What’s the Solution?

For this reason, good trim carpenters will often make sure that a scarf joint “breaks on a stud”.  This means that the joint occurs directly over the position of a stud in the wall.

This allows the carpenters to drive a nail through the joint and into framing lumber behind it. That way, they firmly trap the two pieces in place. Careful carpenters take the extra measure of glueing the end grain of the two pieces where they overlap. This further ensures that the joint doesn’t split or move as the house lumber expands and shrinks throughout the year.

Basically, the rule of thumb with scarf joints is that if you see more than just the faintest trace of a seam, the joint could have been cut or fastened a little bit better.

3. Reveals

“Reveals” are among the most overlooked and understated elements to be found anywhere in architecture. At some point I’ll devote a whole article to them — I really think they’re that important! But, for now, a simple explanation will do.

Reveals are just linear offsets between two pieces of wood that run parallel to each other. Look at the picture below. Here, the casing on the outward facing wall sits about 1/4″ away from the edge of the inward-facing jamb. (The fillet strip above does the same.)

reveals in craftsman door

Reveals are small offsets between two parallel trim pieces.

This offset creates what looks like a little ledge between the two pieces. (Which, of course, is really just the edge of the inner piece showing a bit.)

The reason these reveals are important, is that they hide irregularities in the edges of the two trim pieces. Remove the reveals and bring these casing edges flush with one another, and you see that neither is truly straight!

The two pieces would wander inward and outwards and away from each other by tiny degrees. You see an uneven crack that is still seen after painting. Even a reveal that is too small will show problems over a run of just a few feet.

not enough reveal in this doorway

The reveal in this doorway is too small.

So, reveals are sort of an ingenious way of solving a problem by creating a bigger imperfection. Just slide the edges of the two pieces away from each other (usually about 3/16″). The minor differences get lost, and a pleasant-looking complexity appears in the trim casing. Take a look at the trim and cabinets around your house. You’ll see reveals everywhere!

Understanding reveals really helps you understand the whole world of trim carpentry. Elaborate trim profiles are achieved by creating a series of built-up offsets and reveals from numerous smaller elements. This is most often seen with crown mould and fireplace surrounds. The complex build-up of individual profiles makes a very pleasing sum.

4. Coped Joints

Coped joints, or “copes,” are a type of joint used to bring two trim pieces together in an inside corner. Like returns, copes are indicators of a high level of attention to detail.

For 90 degree inside corners, carpenters cut two 45 degree miter cuts (one on each piece). The idea is bring two pieces together in an attractive way. Unfortunately, there are often discrepancies in the corner angle. Wood also expands and contracts with the seasons These problems cause mitered joints to “open up” over time. (That assumes the joint well to begin with!)

Carpenters minimize these problems by using coped joints to bring two pieces together.

coping joint on crown mould

This cove mould has been “coped” to create a 90 degree corner.

For a cope, cut the profile shape of the trim being used onto the end of one piece. This allows it to slide like a puzzle piece against the trim piece it’s meeting. (See above).

Making copes is very laborious compared to cutting simple 45 degree miters. But, good trim carpenters will cope every inside corner in a house just to ensure a good fit.

The irony is that it’s almost impossible to distinguish between a miter joint and a coping joint once caulk is on! However, on jobs where the trim is stained, you can’t use caulk.  Coped joints are mandatory.

So, remember, if you hire trim carpenters for a project, ask if they cope their corners. Or do they miter them? If they cope, they show that you’re dealing with someone who prioritizes craftsmanship over speed.

5. Fill-ins

Probably the easiest trim details to spot in a house are “fill-ins”–or, more importantly, the lack thereof! Empty spaces!

Fill-ins fix these problems. They fill small natural gaps on a wall, mainly around doorway casings. In some of these situations, the gap is hardly bigger than the thickness of the casing itself.

In high-speed trim installations, carpenters just terminate the end of a trim run at the wall. Then they fill the remaining space with caulk (if they even bother). Yuck!

small trim fill in in living room

Even small gaps should get their own fill-in trim pieces

Ideally, these gaps should be treated like every other inside corner in the house. They should receive a tiny fill-in trim piece of their own. Then, the longer piece meeting it can coped for a good fit. Now you have is a clean looking corner, rather than an eyesore.

Trim Work Wrap-up

There are countless details that distinguish quality trim work from inferior work. But, these five represent the most common — and I feel most important — carpentry considerations in trim work.

If you’re looking at homes to purchase or rent, just run your eyes over the trim and casings. Home in on these five key points. That way, you’ll be able to read the story of how well the trim was installed!


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