Wondering how long does it take for a house to settle? If so, don’t hit that back button because that’s what we’re going to talk about in this article. We’ll go over foundation settlement, the two types of settlement, what causes settlement, repair methods for settlement, and more.
But first, let’s answer the question:
How Long Does It Take For A House To Settle?
Here’s a secret: We actually don’t know. We only know how to permanently stabilize a houses foundation from settling and how to re-level them.
Every structure that is not built with a deep foundation system connecting it to bedrock will eventually settle some, but how much is anyone’s guess. Typically only large high-rise buildings or infrastructure are built with deep foundations. It’s cost prohibitive to do this with residential buildings.
When we conduct a foundation inspection on a house and perform a floor level survey (survey of the highs and lows, down to 1/8” increments of your floors) we know the measurements we are taking that day are just a snapshot in time over the 40, 50, 60, 70, 80 year – or more – history of your house.
If your house is 48 years old and has a 3” slope to one corner, it’s possible that the corner settled a perfect 1/16” every year in its existence.
It’s possible, but not likely.
When we visit a house we ask questions like “How long ago was the inside of your house painted?” or “When was the kitchen remodeled”. If we’re seeing damage in an area and we know the last time the cracks were patched or painted, we can try to piece together how recently it occurred.
If you’re house has settled…
You can choose to fix your house at that time or you can choose to wait. Your house isn’t going to settle an inch overnight. It might not settle an inch in a full calendar year. However, if your house has a history of settling and no changes are made, chances are it will continue to settle. We do know that the problem isn’t going to magically fix itself. If you choose to wait, you can re-measure your house after a year has passed to see if it has continued to settle. We’ve seen houses that had 5 inches of settling that didn’t change over a decade. However, we’ve also seen homes that had 1 inch become 1-3/4 inch in a span of just 2 years.
Do Homes Go Through an Initial Settling Period After They Are Built?
Yes, they do. However, today’s new homes don’t settle as much as new homes did in the past. This is because homes built today have soils reports, soil compaction requirements and drainage systems integrated into their design to keep them from settling excessively. Today, the allowable rate of settling is 1” over a 20’ span.
In contrast, older homes had less stringent requirements when they were built. Soils reports were rare and drainage systems were mostly an afterthought.
So, What Exactly Is Foundation Settlement?
After they’re built, it’s normal for houses – or any other structure – to sink uniformly into the soil slightly. The problems start when the foundation settles into the soil un-uniformly. This is called differential settlement, one of the leading causes of structural damage. Check out the illustration below to see the difference between uniform settlement – which is expected – and differential settlement, which is not normal. Any amount of differential settlement is bad because it puts stress on the foundation.
Uniform vs Differential Settlement
As we noted above, a slight amount of uniform settlement is pretty normal after a structure is built. You can even expect it. In other words, it’s nothing to worry about.
Differential settlement is when a structure settles unevenly into the soil – even slightly. Differential settlement is not normal. It puts stress on the foundation and throws everything out of plumb. If your house is experiencing differential settlement, you might notice cracks, uneven floors, doors and windows that no longer open and close properly, stair-step cracks in brick or masonry, etc.
Differential settlement is a serious problem that gets worse over time. It must be repaired immediately by a foundation repair contractor. If you wait, the problem will be more expensive to fix.
What Causes Differential Settlement?
People are usually surprised to hear that earthquakes have little to do with differential settlement. Earthquakes will shake a house and cause cracks, but unless the earthquake causes significant soil shifting or sink holes, it probably won’t cause differential settlement.
Some of the biggest factors that cause foundations to settle are…
- Soil that wasn’t adequately compacted before the house was built – Soil needs to be tamped down before construction. If this doesn’t happen or is done improperly, the structure will settle unevenly into the soil after it’s built.
- Poor drainage around the foundation
- Expansive soil – Expansive soil is soil with a lot of clay. It expands when it soaks up moisture and shrinks when it dries out. Over time, this swelling-shrinking cycle can lead to differential settlement because it creates movement under the foundation.
When your house is on expansive soil with poor drainage, you will likely experience a fair amount of seasonal movement. One manifestation of this is a door that sticks in the summer works great as soon as it rains. This happens because expansive soils dry out and contract (i.e., shrink) during the summer and then re-expand when they get wet in the winter.
Other causes of differential settlement include:
- Invasive tree roots – Tree roots looking for water can “drink” moisture from the soil under and around the foundation, creating voids. Differential settlement happens when the foundation sinks into the voids.
- Natural disasters – We probably don’t need to explain how earthquakes might cause differential settlement leading to structural damage. However, floods, sinkholes, tornadoes, etc., can also cause differential settlement.
- Heavy excavation next to the foundation – If your neighbor digs a big hole too close to your house, it could destabilize the soil under the foundation leading to differential settlement.
- Weather changes – An example of this is a home built on expansive soil during the dry season. As soon as the rainy season rolls around again, the ground under the foundation swells, pushing the foundation upward. For more information about expansive soil see, .
Possible Signs Of Differential Settlement
Signs of differential settlement include:
- Trouble opening and closing windows and doors
- Wall cracks, especially horizontal and diagonal cracks. (Hairline vertical cracks are usually caused by shrinkage during the concrete curing process and are merely unsightly.)
- Floor cracks, especially a crack that goes from wall to wall. A crack limited to one or two tiles probably happened when something fell on the floor.
- Ceiling cracks. Sometimes a crack will go across the ceiling and down a wall.
- Uneven floors
- Moldings that are separating from the wall or ceiling
- Stair step cracks in brick or masonry
- Torn or wrinkled wallpaper – This could be a sign the wall behind the wallpaper is cracked.
- Chimneys or porches that are separating from the house
For more information see,
Repairing The Damage Caused By Differential Foundation Settlement
Obviously, you can’t change the soil underneath your house. Therefore, the most effective way to stop a foundation from settling is via underpinning. Underpinning the problem area and improving drainage on the site can also help prevent the unaffected areas from settling in the future.
What Is Underpinning?
Underpinning takes the problematic soil out of the equation by connecting your foundation to bedrock. Underpinning strengthens a foundation so it’s no longer susceptible to unstable soil. Resistance push piers are the most common method for underpinning a settled foundation. Other methods of underpinning include helical piers and drilled concrete piers.
Underpinning an entire house is rare. Most of the time only one area is affected (This might be be one corner, 1/3 or sometimes ½ of a house) and the rest of the house is relatively fine.
Underpinning process using push piers
The installation procedure for galvanized involves excavating the pier location exposing the bottom of the foundation, attaching heavy-duty galvanized steel brackets to the foundation, and then driving the galvanized steel pipe through the brackets until they reach stable soil or load bearing strata. Hydraulic lifting jacks then lift and stabilize the foundation from any future settlement. Once lift and stabilization is complete we remove the lifting cylinders and back fill the pier location with dirt or concrete.
Underpinning using helical piers
Helical piers are another method for underpinning a foundation experiencing differential settlement. Helical piers look like giant corkscrews and are used for underpinning lightweight structures experiencing differential settlement. They’re also used for new construction products requiring a deep foundation system.
Helical piers are turned into the ground until they reach the required depth and torque necessary to support the foundation. Synchronized hydraulic cylinders then lift the foundation. The cylinders are removed, and the helical piers stay in place.
When Is the Best Time to Fix My Foundation?
The best time to fix your foundation is before a remodel or when your house is experiencing problems like doors and windows that aren’t opening and closing properly, wall cracks, etc.
If the foundation holding up your kitchen or master bathroom is settling and you are planning on spending big money on a remodel, it’s best to have the underpinning done before you start work on those projects. Nothing is worse than installing new cabinets, countertops, and backsplashes, and then watch them start to shift and crack.
Will Insurance Cover Foundation Settlement?
Homeowner’s insurance usually doesn’t cover damage caused by foundation settlement unless the settlement was caused by something for which the house is insured—for example, earthquakes.
How To Prevent Differential Foundation Settlement
Because water causes most foundation problems, you can help prevent foundation issues, including differential settlement, by controlling groundwater around your foundation. Your goal is to keep the soil from becoming too wet. Here are some ways to do that:
- If necessary, regrade your yard, so it slopes away from the foundation. You don’t want a yard that slopes toward your house because water will drain toward the foundation.
- Don’t plant vegetation – flowers, shrubs, trees, etc. – next to the house. You don’t want a reason to add water to the soil around the foundation.
- Make sure your gutters aren’t clogged. Gutters full of leaves and other debris will cause water to spill over the side of the house and soak into the soil.
- Install downspout extensions so that runoff is carried at least four feet away from the foundation before being released.
- Install a drain tile system – When preventing the build-up of excess moisture in the soil around the foundation, you can’t beat a drain tile system. A drain tile system works by ensuring excess moisture can’t build up in the soil around the foundation. There are both interior and exterior drain tiles systems.
For more information, see .
If you’re concerned your house might be settling non-uniformly, and you’re in our service area in Northern California, contact us today for an inspection and estimate.