Fascia boards are one of most common areas for rot on a house. Their position just beneath the roofline makes them highly susceptible to water penetration, and once the boards become soaked, they’ll quickly begin to deteriorate.
This article will give you an overview on how to carry out fascia trim replacements. But, if you tackle this repair, please take all safety precautions! Fascia sits high off the ground, and most of the work will have to be done from a ladder.
6-in-1 Painter’s Tool
Cat’s Paw Tool
16 oz. Hammer
Trim Lumber (match existing–or better yet, use PVC!)
2″ Spiral Shank Nails
Siliconized Latex Caulk
Primer / Exterior Paint
(Tools and materials are linked below strictly for informational purposes–no marketing revenue is generated through these links.)
Step 1. Determine That You Actually Have Rot
Rot and simple discoloration are two different things. In some cases, spillover from the roof or a gutter can just gunk up a fascia board.
Actual rot will show up as soft spots or dark cavities in the surface of the board (like the one pictured above). Wood in these places will be mushy and pulpy. To test an area that you’re unsure of, use the steps in this short Q&A I wrote about rot testing.
If you’re positive than an area is rotted, you should next identify where the water came from.
Step 2. Identify The Water Source
In order to carry out an effective fascia repair, you must first identify why your fascia got wet, and then do your best prevent water from soaking this area in the future.
Chipped or damaged shingles can be a common source of water reaching fascia. Look at the lowest course of shingles on your house.
Are your perimeter shingles damaged? If so, have them replaced. Also consider having your roofer add a drip edge to your house—this metal strip sits under shingles and kicks water away from the fascia boards
Gutters are another common source of dampness at the roofline. If gutters aren’t channeling water properly (because they’re either full, or hung the wrong way), they will frequently spill water back towards the house.
Have your gutters cleaned regularly. If your gutters still fill up or spill water in odd places, you might want to consider having a gutter expert rehang them. Adding more downspouts to long runs can help this problem. (Here’s a good article on proper gutter hanging.)
Once you’ve identified and fixed the source of your excess water, you’re ready to replace your fascia boards.
Step 3. Remove The Rotted Fascia Board
To start this project, use a utility knife to cut all seams and caulk lines around the piece (or pieces) that you want to replace. This will ensure that the board comes away from the wall without pulling any other components.
Use a six-in-one painter’s tool to pry the board away from the wall gently at the base. Work your way across the board in small increments. You want to avoid prying too hard, too fast.
When you have worked a gap behind the board, you can switch to a hammer to pry. But don’t damage other trim in the area! Hammers can bruise wood easily.
A good trick for getting boards to come away smoothly is to pry out the nails holding them in. You can use a “cat’s paw” tool to gouge out and expose nail heads. (I’m using one here to free the board from a custom aluminum flashing cap, which I will nail right back on to my new board.)
Also, you can sometimes get nails out by giving a half-pried board a sharp whack with your hammer. The force will cause the nail to punch out backwards through the face.
The key in all trim removals is to be gentle. Don’t make more work for yourself by damaging nearby materials with too much force.
If you only want to replace a portion of a fascia board, you can make controlled cuts on the trim face with a oscillating multi-tool. I already wrote an article on this topic—click here to see how this miraculous oscillating tool works, and how you can use it to interrupt trim.
It’s best to try to remove an old board in one piece—it can come in handy later. However, if you can’t get the full board out, try splitting it with your hammer, and pulling it out in narrower sticks.
Step 4. Examine The Sub-fascia
When you finally manage to pull your fascia board loose, take a moment to examine the framing lumber that you’ve exposed.
If the untreated lumber is badly rotted (as it is in the picture above), you may need to replace it before you can put the fascia back on.
In general, you want to reframe the area exactly the same way it was framed originally. You can do this by adding “scab” blocks to undamaged framing in the roof structure. Just make sure everything you add is firmly attached and immobile, and that the sub-fascia sits flush and level across the entire run.
Step 5. Clean The Sub-fascia
If the sub-fascia is in decent shape, clean it up in preparation for mounting the new board. Scrape caulk lines and paint globs with a six-in-one tool. (This includes scraping old caulk at the seam of any neighboring boards.)
Also remove any fasteners that are still sticking out of the sub-fascia. These leftover nails will prevent your new board from sitting where it needs to sit.
You can simply drive down some exposed nail heads with your hammer. If the angle is too awkward, though, or the fastener is bent, you can back it out with a nail puller instead.
Take a moment to really examine the area and make sure it is completely clean of any obstruction. There’s nothing more frustrating than trying to put your new board on, only to find that one little nail is preventing it from sitting flat.
Step 6. Measure For Your New Piece
The absolute easiest way to do this is to simply measure the piece that you tore off. If the old piece fit very well (and you can clean it and hold it back in place to be sure), then use it as a pattern for the new board.
However, if you’ve destroyed the old board in removal, then it will be necessary to measure and plot cuts for a new board.
Producing a new piece can be a little tricky, because fascia wraps around a house. Pieces don’t just need to be the right length—they also need to be the right shape.
Some pieces will have miter cuts on both ends, and even compound cuts where fascia turns up a roofline. Always visualize what you need the next piece to do. If it needs a square cut on one end, and a miter cut on the other end (like the board in this article), then fix that image in your mind.
To measure for my new board, I’ll simply butt my tape measure to the inside corner, and pull to the farthest point of the outside corner. This total measure will give me the distance to the long point of my miter cut.
Sometimes, you’ll need to pull measurements too long for your tape to reach without folding. Or, you might need to pull a measurement from a place where you can’t hook or butt your tape (like a scarf joint for instance).
In these instances, it can be extremely helpful to drive a trim nail at that location, and hook your tape onto it. You can add or subtract an 1/8” of an inch in necessary to account for the size of the nail.
Step 7. Cut The New Board
The most important thing to note here is that you should always replace fascia boards with PVC materials. These plastic-vinyl boards are inorganic, and therefore impervious to rot. For water-sensitive places like fascia, PVC is the best option.
If you do want to use wood, make sure you’re at least using quality lumber. Try to get clear pine, as opposed to knotty pine. And don’t use any manufactured board that has finger joints—they’ll fail more quickly over time.
Also, get PVC or lumber that matches the thickness (probably ¾”) and width of your fascia board. (You can rip boards down to proper width with a circular saw or table saw if necessary.)
To make your cut, just lay out your required measurement and mark it with a V-shaped pencil mark (“crow’s foot”). Use a speed square to draw a straight line through you’re the point of your mark.
Again, always keep in mind what face of the board your looking at. If there is a miter cut on your new piece, consider that there will be a short point of the cut, and a long point.
Using a miter saw for your cut is easiest, because you can lay the blade down to 45° for your cut and press the board back to the fence.
A circular saw has a very similar capacity, though—just unlock and swivel the sole plate to your desired angle. You can use your speed square as a straight edge to guide your saw as you cut. (Just be sure to hold your speed square firmly! Don’t let it wander.)
Cut through your pencil line and let the waste fall away. When the cut is finished, pull a measurement on your board just to make sure the board length is accurate.
8. Attach The New Board
I generally like to take the board up for a quick test fit before I try to attach it. But first, I’ll often half-drive one nail into the board—a little carpenter’s trick that might help later.
(Always use galvanized, exterior-grade nails for exterior trim. I like to use 2” spiral shank nails for fascia boards. They’re long enough to reach through the fascia and most of the sub-fascia, and the spiral gives the nail a very firm grip in the wood.)
Hold your new board in place against your sub-fascia. Examine the seams where it meets other boards (or have someone on the ground do it for you if the board is long.)
Small gaps of 1/8” are totally tolerable here. I sort of like to have my fascia boards just a little short—it let’s me caulk into the gap for better water seal.
If the board is a little long, take it back to the ground and trim it. However, if the board fits, your half-embedded nail comes in handy here. Just drive it to lock the board in place. You can now add the rest of your fasteners.
Fascia boards have very little pressure on them. There’s no need to go overboard with fasteners.
A high nail and low nail every couple feet is all it takes to secure the board in place. (Just make sure you’re fasteners are sinking firmly into the sub-fascia behind the board.)
9. Caulk The New Board
This is a straightforward procedure. Just cut the tip of your caulk tube to allow about a 1/8” flow. Squeeze and smooth beads at all seams and junctures (including along the bottom if there is a lower skirt fascia, as there was in this project.) Just be sure you’re using siliconized latex caulk for exterior applications!
Also, drive your fasteners slightly below the surface of the fascia with a hammer and nail set. Caulking these divots will help hide the nail heads.
After a little dry time, you’re ready for a couple coats of exterior paint. If you removed gutters from the project area, you can rehang them, and you’re all finished.
There are, of course, about a thousand variations on this repair. For instance, not all fascia will look like the one I’ve fixed above, which is a decorative double fascia.
Many fascia boards will hang down in open space, creating the “eaves” of the house. These eaves often enclose a suspended “soffit”—a thin board that hides the rafter tails.
If your soffit is rotted, you’ll need to replace runs of that as well. This is a slightly more involved procedure, but also not too difficult. (I promise I’ll write about it in the near future!)
If you’re soffit isn’t rotted, though, your repair will be much like the one I’ve depicted. Just remove old material gently. And, of course, PLEASE BE SAFE!
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