How to Replace Rafter Tails

What You'll Need
Measuring tape
Replacement rafter tail wood (measured according to the steps below)
Dowel pegs
Exterior glue
Waterproof filler
Sealant and paint (optional)

If you have damaged rafter tails, your roof is at risk of flooding, rotting or potentially even collapsing. This condition is a serious one, and you should take the time to replace any rotted or damaged rafter tails quickly and before the issue becomes worse. Fortunately, replacing rafter tails is a straightforward process, although it can be a bit tricky. Read on for some tips on how to replace the ends of damaged rafter tails.

Step 1 - Gather Your Materials

In order to replace your rafter tails, you'll need to plan on cutting off the bad wood and replacing it with new, solid wood instead.

Step 2 - Measure and Cut Your Replacement Tails

Find the rafter tail that has the most damage or the largest section of rotted or bad wood. This is the section that you will use as a model for the other replacement pieces. Measure how long the section of bad wood is, and add several inches to that length. Using your tape measure, cut replacement tails to fit this shape. They should match up with the height and width of the rafter tail as it exists already. The goal is to produce rafter tails for each of the different rafters that has bad wood; by cutting each of the tails to the longest length that you'll need, you save yourself the trouble of having to measure and cut each tail separately.

Step 3 - Cut off the Bad Wood

Taking particular care to be safe and to not cut any wood that may be directly supporting something else, cut off each of your rafter tails at the length that you measured for the replacement tails. You do not need to worry about sanding the tail ends down at this point.

Step 4 - Attach the New Tails

Use a dowel peg to help mount the replacement tail on the existing rafter. You'll also need to secure it in place using exterior wood glue and screws. When in doubt, make sure that the tail stays in place using all 3 of these methods, as the combination will help to make the tail even more secure.

Step 5 - Seal the Cracks

Before you sand or treat the new rafter tail, it is important to use a waterproof filler to seal the cracks that will naturally occur between the existing rafter and the new tail. Be sure to allow the filler time to set and dry before continuing.

Step 6 - Sand, Seal and Paint the Tail

Use sandpaper to sand down the joint between the old rafter and the new tail. Treat the new rafter tail with sealant to help protect it, and then paint the rafter tail according to your design specifications, if you wish.

If you have any questions, consult with a home improvement expert for additional assistance.