Replacing Rotten Hardboard Siding on Your Home
By: Danny Lipford
Hardboard lap siding has been used on homes for years because it mimics the look of wood siding but is much less expensive. One of the disadvantages of hardboard siding is that exposure to water can cause it to deteriorate over time. This is most common on the bottom few courses near the foundation.
If you have this problem, you might want to consider replacing the rotten courses of hardboard siding with more durable fiber cement siding. Fiber cement siding is available in the same look and dimensions as hardboard siding but is more resistant to water damage. It also doesn’t cost much more than hardboard, and it’s a fairly easy to make the repairs yourself.
- Tape measure
- Pry bar
- Circular saw with masonry blade
- Caulking gun
- Plywood sheathing
- 15-lb. builder’s felt or housewrap
- Fiber cement siding
- Hot dipped galvanized or stainless steel nails
- Paintable exterior caulk
- Exterior paint
How to Remove and Replace Siding:
- Remove Damaged Siding: Remove the deteriorated hardboard siding using a pry bar and chisel, being careful not to damage the good siding above it.
- Replace Rotten Sheathing: If needed, replace the sheathing behind the siding using 1/2” plywood covered with builder’s felt or housewrap.
- Cut Fiber Cement Siding: Cut the fiber cement siding to length. Always wear an approved dust mask or respirator when cutting fiber cement.
- Install Fiber Cement Siding: Nail the fiber cement siding in place so the rows are consistent with the rest of the wall. Fiber cement siding can be blind nailed near the top of the siding to eliminate exposed nails. Nail the top course of fiber cement siding through the lower course of hardboard siding.
- Caulk and Paint Siding: Caulk the end joints in the siding, then paint the siding with quality exterior paint.
Watch this video to find out more.
- How to Replace Damaged Hardboard Siding with Fiber Cement (video)
- Replace Water Damaged Siding With Fiber Cement Siding (article)
- Fiber Cement Siding: A Durable Alternative (article)
- Advantages of Fiber Cement Siding (video)
- How to Install Fiber Cement Siding (article)
Danny Lipford: Hardboard lap siding like this has been used on houses for many, many years because it looks like wood but it’s a lot less expensive. But one of the drawbacks with using this kind siding is if it gets wet and stays wet, it can deteriorate very quickly.
In fact several of the pieces of the siding had to be replaced here on the driveway side of the house, as well as behind the house where the deck meets the house. That’s where the rain is constantly falling back against the house, keeping it wet and causing the siding to rot.
Now, we replaced the siding with a different type of siding called fiber cement. Fiber cement siding is resistant to this type of decay and is available in the same dimensions and patterns as the hardboard products, so you don’t have to replace all the siding on the house, just the pieces that are damaged.
Now, the process is fairly simple. You remove the old siding carefully without damaging the pieces above it. Now, underneath this siding, we also had to replace the sheathing, so we used half-inch plywood and a layer of builder’s felt.
The fiber cement siding is nailed in place so the rows are consistent with the rest of the wall. Because cement is the largest component of the siding, it’s hard on saw blades. So if you’re cutting much, a masonry blade is a great idea.
After installation, you caulk and paint it like any other siding. And the homeowner here decided to even change the color. And another great thing, it costs about the same as hardboard siding.