How to Replace Box Gutters

What You'll Need
Roofers shovel
Hammer and nails
Roofing cement

You can find box gutters on many older or historical homes because the box gutter used to be the main gutter type installed. A box gutter differs from modern gutters as it does not attach to the fascia or trim as an addition to the house. A box gutter is a part of the home structure that exists at the bottom of the roof section and acts as an attached roof channel for runoff. When a box gutter system is failing due to leaks, rotting or corrosion, one option you have is to replace the box gutters with a more modern gutter system.

Step 1 – Remove Roof Shingles

Before you can remove the existing box gutter, you need to remove the shingles surrounding, connecting to or overhanging the gutter. Use a roofer’s shovel to pry up the shingles by sliding the shovel under the shingle and slightly twisting it. By twisting the shovel, you will pry up the roofing nails and release the shingles from the roof. You only need to remove the shingles that connect to or touch the box gutter itself. After removing the shingles, pull up any extra nails from the roof that are remaining.

Step 2 – Remove the Box Gutter

After removing the shingles exposed to the box gutter, you are ready to begin removing the old box gutter. The steps to remove the box gutter itself will vary depending on its installation. The installation of most box gutters will require attachment to an outside section of your roof (under the shingles). You first need to release the attachment by removing any screws or nails securing the box gutter to the roofing structure. More than likely you will find a nail or screw attaching the gutter to each rafter tail. Depending on the gutter installation, you may need to actually cut the wooden box gutter channel to separate it from the roof. For this, you can use your jigsaw. If cutting is not required, remove the box gutter channel from the roof.

Step 3 – Inspect for Damage

After removing the box gutter, you need to check the roof and surrounding wood for rot, decay or damage. If you find any rotten or decayed areas, you need to repair or replace the wood before proceeding. You can easily cut sections of wood from the roof, fascia or trim boards that need replacing. Measure the rotted piece after removal and cut a duplicate sized piece from good wood. You can then nail the new wood piece into place to replace the rotted area.

Step 3 – Replace the Roof Shingles

Now you are ready to replace the shingles and complete the roof. Start replacing the shingles on the outside upper corner of the area where the shingles need replacing. Apply asphalt roofing cement to the back of the shingle and lay the shingle in place. Lay the shingle so that it slightly overlaps the previous shingle and covers the nails of the previous shingle. Secure the shingle in place by nailing it to the roof with the nails placed toward the outside of the shingle so the next shingle will cover them. Continue this process with the remaining shingles until the roof is complete.

Step 4 – Install New Gutter System

Now that the roof is complete and you have verified the integrity and soundness of your fascia or trim board, you can begin the installation of your new gutter system.