What part of your house is the structure?
Before we talk about structural repairs, its worth discussing what part of your house is the structure. It’s common to think that everything under your feet is your home’s foundation. While it is down there, that’s not entirely true.
In most residential construction, the concrete portion of your house, whether that is poured concrete or cinderblocks, is your foundation. In a slab-on-grade foundation, concrete makes up the foundation elements as well as the flooring system. Some houses are made entirely of cinderblocks and structural concrete walls. In general terms, it works, to say the concrete is the foundation.
That means the wooden portion of the house is the structure. Wooden foundations are possible. An example would be a house built on wooden telephone poles near the water.
In the Upstate of South Carolina and most of the South East of the United States.
Concrete = Foundation
Wood = Structure.
That distinction is helpful in determining the types of repair needed. The signs of foundation and structural problems have a lot of similarities. You might need a qualified professional to sort out the difference. However, many instances, like damage to the wood, will be quite obvious as a structural problem. Let’s look at some common causes of structural problems in our area.
What creates a need for structural repairs?
Deficiencies in design or construction.
We’ll start with the one that happens everywhere houses are built. Mistakes happen, errors are a part of life, and things get old. When houses get built, there are thousands of things that come together to end up with a finished house. Along the way, mistakes can and will happen. Some times mistakes are obvious right away, and sometimes they can take years to become evident. What we mean by a deficiency is that the framing of the house is not able to support the weight it is tasked with supporting for the life of the home without allowing a noticeable amount of deflection or dipping.
Common types of these deficiences are:
- A wall with only one-floor joist under it.
- W wall that sits between two-floor joists and is supported only by the subfloor.
- A joist that has been cut/notched/drilled through in a way that compromised it to allow utility access.
- A wall that sits off a girder and is supported only by floor joists.
- Floor joists or girders that are over spanned.
- Floor joists spaced too far apart.
- Load paths that have changed due to a remodel.
- Loads that have increased over the original design specifications. This is caused by modern appliances, a water bed, a big fish take, a gun safe, or other heavy items.
Once the problem has been identified, these structural repairs are often as straightforward as adding support and increasing the strength of that area. That does not mean this is always easy to execute, but it’s at least straightforward.
In the forest, when a tree falls, termites play a vital role in breaking them down. Unfortunately, their little insect brains are programmed to eat and break down any wood they come across, including our houses at risk.
In the South East we only see subteranean termites. This means they live underground and get into our homes from the bottom up. (Some termites fly and will eat a house from that attic down, but luckily we don’t get them here). Because they live in the dirt, they devour wood close to the ground. This is bad news for a home with a crawlspace. In out of site areas they can do a lot of damage before anyone even notices they are there.
These termites require moisture to stay alive. As a result they like wood that is staying wet from a leak, rain, or lack of drying. They can eat dry wood that is close to the ground as well, using their tunnels to stay moist. We see more termite damage in homes with shorter/lower crawlspaces, crawlspaces that stay moist, or in areas where water is getting to the framing, and there is no drying out. Without persistent water exposure, it is not common to see termite damage extending more than a few feet above the crawlspace.
What can be done about Termite damage?
Typically with termite damage, when it has significantly compromised the framing, the structural repair is to replace everything damaged with new lumber—usually, going right back to the original framing patterns, taking the home back to where it was the day it was built.
Before a termite repair is made, termite treatment should be done on the home. This makes sure the repair doesn’t send the termites to other locations. It also prevents the termites from coming back. Any home in the South East should maintain an active termite treatment to prevent any major repairs.
We think of this as the termite’s fungal cousin. Dry-rot is a wood-eating fungus that, like a termite, requires moisture to live. Dry rot needs a moist environment to live. It can stay dormant above about 75% relative humidity and thrives when things stay about 86%. In the wood itself, it needs the moisture content to stay about 20% to stay alive and gets really active in the 28% to 30% range. (Annoyingly, your fingertip stays a just about 30% moisture, and thus, its ideal living surface feels dry to the touch).
Dry rot eats the fibers in the wood that give it both stiffness and strength. While there is plenty of visual evidence that dry rot has set in and is at risk of causing real damage, the first symptoms from inside the home tend to be small dips leading to bigger dips, and boards lose more stiffness and eventually break.
Dry rot is common in crawlspaces that do vent well or that have poor air movement, ones that take on water and dry poorly after a rain, in areas with slow long-term plumbing leaks, or under uncovered doors where small amounts of moisture get in with every rain and dry very slowly.
What can be done about Dry Rot
To help control and prevent dry rot in a crawlspace, it is essential to be able to maintain a low relative humidity. This can be accomplished by adding a drainage system if rain water is the cause of the moisture. Some crawlspaces based on construction are unable to get enough air movement and do not naturally vent enough to maintain a low relative humidity without intervention. In those cases sealing the crawlspace and creating a controlled space through a process called encapsulation allows a dehumidifier to regulate the relative humidity of the crawlspace and prevent both mold and fungal growth.
The structural repair process for dry rot is generally a two-part procedure. The first stage is the restoration of the structural integrity of the framing. The damaged and weak boards are removed and replaced with new lumber. This restores the strength of the framing and, where ever possible, gets rid of any wood that contains the dry rot fungus. Once the damage has been repaired, the second stage is prevention. The high humidity or leak that led to the dry rot thriving needs to be corrected so that future repairs are not needed. In this instance, it is not enough to correct the damage; just like with getting a termite treatment, you want to ensure the repairs only need to be done once.
Do you see a theme here? Water is the leading cause of damage to our homes and the number one reason we make structural repairs. Whether the water is making an environment more inviting for mold, fungus, and wood-damaging insets or it does the dirty work itself, it is a problem for our homes.
Wet rot, like dry rot, is a fungus but in this case, it like the wood moisture content to be above 35%, and it likes to stay wet continuously. Wood, as a formerly living organism, can get wet and actually does really well with getting wet; it just has to be able to dry out. Wood can take a fair amount of water exposure, and even repeatedly if it can quickly and adequately dry out.
Wet rot is common in areas with a persistent plumbing leak or a non-southern-facing side of the house with persistent rain penetration. (It’s possible for this to happen on the southern side of a home; they tend to get a little more drying help from the sun). This means these repairs often happen under the kitchen sink, near a bathroom or laundry room, and around the water heaters.
The repair procedure, like dry rot, is two-part again but taken in the opposite order. For the sake of the folks doing the repair and the new materials going in, the first portion of the repair is to stop the leak and get things dried up. The second phase is then to remove and replace any of the damaged building materials.
Caught soon enough, all of these issues can be solved with minor repairs, but when things get bad they can lead to very extensive amounts of re-framing and major repairs.
Our experts are trained to both diagnose the right repair path and prevention steps to ensure that as great as we are to have around, we only have to spend time together once.