Remediating Termite Damage
26 Dec 2017Termites can be a big problem for wood framed homes in the southeast. I bought my first house knowing there was some termite damage. There was evidence of termite damage throughout the house, most noticeably in the wood floors. The previous owner did relatively extensive repairs to fix the termite damage including replacing about half of the first floor joists. While most of the evidence of termite damage was on the first floor, there was a dormer on the second floor that had water damage, and so we suspected that there could be some termite damage around the dormer since termites are attracted to moisture. This post describes the work I did to remediate the termite damage in this dormer.
About termites
Subterranean termites are a common pest. They live in colonies in the ground and seek out wood for food. A colony of termites consumes about a pound of wood per day. Since a termite infestation can go on unnoticed for years, the amount of wood consumed really adds up. Many exterminators provide termite treatments that will keep termite colonies at bay. Once significant termite damage occurs, the damage can be remediated by reinforcing or replacing the damaged wood framing.
Discovery
I started assessing the damage by taking a look at the source of the water leak that caused the water damage. In our first few months in the house, the water damage continued to look worse and worse, so it was pretty clear that the previous owner did not fix the moisture issue as they had claimed. I found that the source of the water leak was inadequate flashing around the dormer. As I suspected, there was also termite damage. However, the damage was much worse than I anticipated. The roof portion of the dormer had almost no sheathing left! The next two images show what I found.
The first image above shows a paper-like hive. The image below shows a dead wasp. It turns out that it’s relatively common for wasps to inhabit areas of homes that have experienced significant termite damage. I was lucky that the wasps were long gone (perhaps because I did this during winter)—encountering a hive while perched on a ladder would have been a terrible experience.
The next image shows the opposite side of the dormer roof where the damage to the sheathing is very bad. The wood that is left has no strength. It crumbles away with light pressure. A couple more wasp hives. Thank god these guys weren’t home.
After finding that the dormer roof was completely destroyed (the shingles were providing most of the structural rigidity), I decided to remove some drywall to see how the damage looked from the inside. The image below shows some damage I found when I removed the drywall.
I was hoping to find some solid wood nearby so that I could remove the damage wood and rebuild the dormer roof. I found that the majority of the dormer was severely damaged and rebuilding just the dormer roof was not practical since there was no solid wood to build from. The only option was to rebuild the whole dormer and a portion of the surrounding wall.
I mentioned above that termites live in the ground. Termites don’t appear on the second floor of a house without first eating their way through the first floor. In retrospect, I should have placed more weight on this simple fact: that termites come from the ground. When termites reach the second floor, it’s quite certain that the damage will be extensive. My case was no different. Removing the drywall to the floor and some flooring showed that subfloor and joists were damaged. So I moved to the first floor to continue the “discovery.” I found more of the same throughout the first floor exterior wall below the dormer. The image below shows the damage to the first floor wall.
When I finally reached solid wood on all sides, the damaged area was about 12 feet wide and 2 floors tall. Much of the wood retained some stiffness and strength. While it might have been a bit faster to sister the studs in some places, this was not an option for the dormer since it’s design is compact and there’s no room for additional boards in many places. I decided to simply removed the bad wood and replace it.
First Floor Remediation
The exterior wall on the first floor was relatively straightforward to replace. I installed some temporary bracing before removing the wall, since it is a load bearing wall. I removed the vinyl siding and set it aside and I removed the door and door frame. Then proceeded to use my sawzall to help liberate the damaged wood. Then I framed in the opening with new studs. An air compressor and a framing nail gun make this a quick job.
Then I installed new sheathing.
I used expanding foam sealant to ensure an airtight connection between the new wall and the old wall and also around the door frame. After reinstalling the vinyl siding and trim around the door, from the outside the wall looked about the same as when I started.
The inside however, looked much better.
Add inside photo here
Second Floor Remediation
Replacing the second floor wall and dormer was quite a bit more complicated than the first floor wall as a result of the angled barn roof and dormer geometry. While I replaced the first floor wall in about two days, the second floor area took four days to replace.
I also took a different approach for the second floor. Since the first floor was relatively simple, it was easy enough to take a couple of measurements and recreate the same wall and door opening after completely removing the old wall. The complexity of the dormer meant that dozens of measurements, both linear and angular, would have been required to recreate the old dormer geometry from scratch. So instead of removing the old rotted wood in its entirety and then building a new dormer from scratch, I replaced a few boards at a time, using the geometry of the old wood as a reference.
To measure angles I used a digital protractor. This tool was handy and allowed directly transferring all the angles of the existing dormer geometry to cuts on new boards on the first try.
The other complexity of remediating the second floor was that it was high off the ground, which was a new variable for me. I had the foresight to know that working on a ladder was impractical for a job of this size. So, I rented scaffolding from Home Depot. I considered buying the scaffolding (also sold by Home Depot) since it was really useful, but I don’t have space to store it, so I opted to rent.
The photo below shows the dormer as I’m re-framing it. You can see that I rebuilt the entire dormer except a few studs to the right—these boards suffered almost no termite damage, so I left them in place. I took this image before I had fully removed the termite damaged wood under the second floor window to the left. The termite damage extended to the left side of the door on the second floor and I replaced that wood as well.
I went a bit crazy with self-adhesive flashing to help make sure that no leaks occur in this dormer in the future. Then I installed new shingles and the white boards for the vertical facing of the dormer.
The final product looks awesome from the outside!
Like the first floor, the inside looks good too.
Final Thoughts
This project was a big project for me and the first time I did any real framing work. I learned a lot in the process. The bottom line is that fixing termite damage is involved and time-consuming, but not impossible for an intrepid DIYer. I think my effort was worthwhile, since now our whole house has been remediated of termite damage. However, it should be noted that structurally, homes (especially old homes) are overbuilt. Small amounts of termite damage are unlikely to cause any real harm or increased likelihood of collapse. Severe termite damage like I found should be remediated, but mild termite damage is usually fine left as is.