7 Steps for Installing Aluminum Trim Coil

The second story of a home with dark blue siding and white trim.

If you are an experienced contractor, chances are (extremely) high that you already know the best way to install aluminum trim coil. However, as the industry gains new talent, education on 'beginner' type projects needs to increase. And while most people are hands-on learners, some may prefer to read about a process before seeing it in action.

For those who prefer to read first, this article is for you.

Let’s look at seven steps for aluminum trim coil installation to ensure you know the ins and outs of the process before you dive in.

1. Get the Right Tools

Depending on the company you work for, you may need to provide your own tools or they might be provided for you.

Either way, you’ll need a tool called a metal brake. A quality brake can cost as much as $3,000, but you can rent one for as little as $60 a day. It is a must if you want to get a professional finish that is durable and will last a long time.

Aside from the metal brake, you’ll need a utility knife to score the coil, tin snips for short or curved cuts, trim nails, a drill and a good hammer.

2. Purchase High-Quality Trim Coil

In order to achieve the highest quality results in any project, you need to start with the best material available. A high-quality coil stock will give you clean, sharp angles, hold its color and resist scratches that lesser quality finishes are damaged by. While you may not be in charge of choosing the product, it’s always important to stay up to date on the latest products and innovations in your field.

Alsco® aluminum coil stock is available in three different finishes and multiple colors so you can choose the one that is best for your particular purpose.

3. Measure

The old carpenter’s adage, “measure twice, cut once,” holds true for aluminum coil stock as well. Your company or client paid for high-quality coil trim, so you want to be sure that nothing goes to waste. Trim coil is normally purchased in a roll that is 24” wide and 50’ long, so the first cut will be to length.

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Measure the piece you need and cut it precisely to those measurements. Most metal brakes are only 12’ long, so keep your pieces at least 6” shorter than that to ensure the brake makes good contact with the ends.

Since you will be cutting from a full roll, lay the roll flat on its side, and pull off what you need. You should make the cut on a hard surface but unrolling it on a hard surface could cause scratches. Using a tape measure, mark the desired length on both edges. Using a metal straight edge as a guide, score the coil trim with a sharp utility knife, being careful to keep even pressure as you make the cut. Score the line more than once if necessary.

Carefully bend the metal upwards until you can crimp the score line. By working it up and down, the cut piece should come free from the roll.

If the coil stock came in a box, put the remainder of the roll back in it to keep it from unraveling.

4. Cut

Now, you will need to cut the piece to the proper width. Utilize the brake for this cut. Using the brake helps keep the material in place to ensure a clean cut.

Determine how wide the total piece of coil needs to be, adding an extra ¾” for a “hem,” which is explained in the next step (but note that sometimes pieces may not require a hem). Mark the measurement on the coil stock on both ends and slide the 24” piece into the open break until the marks align with the edge of the brake’s jaws.

Close the brake and use the edge as a guide to repeat the cutting process as described above. Lift the handle to work the coil up and down until you are finished cutting the material. Now you have a piece that is the right length and width.

5. Bend

The first bend you will make is called a “hem,” and its purpose is to strengthen the trim piece by giving the edge a double thickness — much like the hem on a piece of clothing.

Make a mark ¾” from the edge of metal and slide it into the brake until your mark is even on both sides. Lift the handle all the way so that the ¾” piece is bent as far as it will go. Remove the piece, lock the brake back down and set the bend on the brake. Lifting the handle, finish bending the hem flat.

You should now have a piece of coil trim the exact length and width you need with a ¾” hem on one side.

6. Account for Additional Bends and Edges

Depending on the piece of trim that is being made, you may need to make several additional bends. For a simple piece of fascia, you will only need the hem and another 90° bend that covers the bottom of the fascia board. If you’re making J-channel, there are a couple of simple bends required.

The same will hold true if you are bending stock to cover window and door trim. Whatever your requirements, be sure to carefully measure the length needed for each bend so you start with the right width of metal.

Be sure to note if the piece will need flaps to nail into the house and add that length to your overall measurement.

7. Fasten

Most aluminum coil trim is fastened to wood using aluminum trim nails. If using treated lumber, make sure to cover the wood in house wrap or felt paper before securing the aluminum. These can be found at most hardware stores if your company didn’t provide them for you.

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Work With Alsco to Enhance Your Project

When you embark on a large project, it’s always a good idea to have a trusted advisor to give you guidance. As for Alsco Building Products, we’ve been in the aluminum business since 1947 and help customers find exactly what they need to complete their projects while saving them time and money.

Our seasoned customer service staff is always ready to answer your questions, so contact us today.