Why There Are Cracks in Your House (and What You Can Do About It)

One of the most frequent questions we get at Jim Gardner Construction is some variation of the following:

Why are there cracks in my house?  Why are my floors not level? What should I do about it? 

In this post we’ll break down typical causes and solutions for interior and exterior cracks so you can make an informed decision about how to take care of these issues the right way. 

Common Causes of Cracks in Your Home

Cracks on the interior and exterior of your home, and floors out of level, are generally a symptom of structural issues down below.  Since most people spend very little if any time in their crawlspaces, they are not seeing what are often some fairly obvious deficiencies that are causing these problems.

The root cause of the problem most often occurs with drainage issues (this is especially true in our service area of Oakland, Berkeley, Piedmont, and Alameda CA).  

Inadequate surface and subterranean drainage systems cause water to travel under your foundations, and with older concrete with no rebar, they can develop cracks and shift or settle.  At the exterior walls, this often occurs adjacent to downspouts that are not connected to any underground piping and are allowed to drain freely next to your house (not good).

When this happens, water can spread throughout the crawlspace, or when you are on a slope water will often pop up in the crawlspace after moving under the foundations and will cause dampness, mold and settlement in certain areas.  Settlement can also occur at interior piers that are often shallow, or affect retaining walls on the downhill side of the crawlspace, causing moisture issues in finished or unfinished basements.

Foundations will generally settle at the outside perimeter due to poor drainage, and this can cause floors to sink, sloping towards the outside.  Sloping at points in the interior is generally caused by interior pier or central foundation settlement, and can sometimes be exaggerated by structural inadequacies created by work done in the crawlspace (generally framing that has been removed or modified to accommodate plumbing or heating ducts that has caused weaknesses at those locations).

Cracks on the interior usually occur around doors and windows, or at openings in walls that have a lot of weight being supported above them and are poorly supported below.  These cracks often occur at the corners of these openings at the headers above doors and windows where the weight is concentrated.

How to Fix Cracks in Your Home

Proper drainage is key to preventing additional movement. If French drains and downspout drainage are inadequate or non-existent they should be installed ASAP. If the foundations are damaged or are in poor condition, they should be repaired or replaced. Improper framing should be repaired. Interior piers should be installed that are of proper dimensions to provide adequate support for the loads above.

Once these corrections are made, any future settlement related problems should be minimal.  Leveling can then be completed, though this is often not a simple process.  The stucco has to be cut at the exterior and the floor lifted, and sometimes damage will occur to the interior or exterior in the areas being leveled, in relation to the degree of lifting required.

If the floor slope is substantial this may be a priority, but we minor sloping (generally figured at less than an inch per 10’) sometimes you can get away with leaving it alone.  

This is more of a cosmetic than a structural concern, so your tolerance for the unevenness has to be weighed against the complexity and cost of the leveling work.  

Sometimes it makes more sense to level the floors on the inside by adding various thicknesses of plywood and patching material and installing new flooring.  This is easier in scenarios where floors are already scheduled for an upgrade.

Long story short, leveling, drainage and foundation and structural repairs should generally be done first before any substantial interior cosmetic work is done.  

Clients often have recurrent cracking on the interior that occurs seasonally and is difficult to deal with because it comes and goes.  Once the drainage and structure are fixed then cracks will be much less likely to recur and interior cosmetic repairs should no longer need to be redone … saving you a lot of money in the long-run. 

If you live in the Oakland, Berkeley, Piedmont, or Alameda area and would like a quote on getting your home’s cracks fixed once and for all, contact us for a quote

How Much Do Foundation and Drainage Projects Cost?

One of the most common questions we get from customers is: 

What do foundation and drainage projects cost?

If you need foundation repair or drainage work done and you live in the Bay Area, chances are you’ve gotten prices that are all over the map.

And the truth is, the costs of doing foundation and drainage work can be really confusing. As is the case with a lot of structural projects, the confusion often stems from a lack of a well-defined scope of work.

In this article, we’re going to share something our competitors in our service are of Oakland, Berkeley, Piedmont, and Alameda wouldn’t dare put in print: cost ranges for foundation and drainage jobs!

We’ll also share some insider tips for making sure you choose a contractor that doesn’t turn your dream house into a nightmare. 

Let’s get started … 

How Most Foundation and Drainage Repair and Replacement Jobs Start

Most foundation and drainage projects start as a result of a report created during the home purchase or after, or signs of damage or concerns either in the crawlspace (if it is easily viewed) or cracks, sloping floors, or other issues in and around the home that seem to be a sign for concern.  

The actual cause of these problems usually requires a detailed crawl in the often tight, poorly accessible areas under you home- places that are often not carefully explored.  During our estimates we try to look thoroughly in all the key areas under your house, since what you notice above is generally a reflection of what is happening under your house.

From the structural perspective, the most common reports generated during a house sale are often poor or incomplete types of information. A few examples … 

  1. The Home Inspection Report is highly detailed but very general.  
  2. The Termite Report has solutions that are primarily to alleviate termite and dry-rot problems which are often poor structural solutions.  
  3. It is rare to get a good Engineering Report on a building (because it can be expensive), and even then it is often technical and confusing. And there is very little if any good pricing associated with these.

So you know you have a problem, but you’re not exactly sure what it is or what it costs. Next, you go contractor hunting … 

How Most Homeowners Choose a Contractor

Due to the fact that very few contractors are structural specialists, and most contractors doing drainage/foundation work tend to be inexperienced, you usually end up dealing with generalists who do not have a good handle on the nature of your problem.

That’s not good. 

And it’s even worse with drainage, because most drainage contractors lack the knowledge and experience to handle more complex drainage jobs.  Then you layer on top of that the guys who are trying to sell you the version of the job they are most comfortable with (not the one that’s the best solution for you) and you end up on the “Contractor Ferris Wheel” with the ride stuck in mid-air … and eventually going downhill from there.

foundation drainage oakland hills ca
Not the direction you want to go in!

There is a better way though–a smarter method for those of you who want your foundation to last and your house to stay dry. 

Let’s look into foundations and drainage separately in more detail so you can better understand what we’re talking about …

Foundation Costs 

How do you even know if you need a new foundation?

It’s a basic question, but surprisingly there’s not a simple answer.  

We evaluate foundations mostly on visual inspection and minor probing of their condition–the number of cracks, the relative size and depth of the footings, grade issues, but most importantly the relative strength of the materials.  

Unbeknownst to many, the real enemy for foundations is water (as it is for most construction materials).  

Concrete is somewhat porous, and over many years older concrete will degrade if subject to a lot of moisture because of drainage related water. 10-20% (or so) of the older foundations we look at have concrete that is so poor you can pull chunks of it out with your hand.  Clearly not a good sign if the plan is for the foundation to support your big heavy, home.  

And given the fact that most wet foundations last around 100 years in our service area and most of the homes were built between 1910 and 1930, and that they have little if any rebar in them, many foundations need replacement.  

I grade them on a scale of 1-10. 1-2 means “you better replace it ASAP”, but beyond that it becomes more of a judgment call. 3-5 is more of a question of longevity–if you plan on living in the home for a long time, we usually recommend replacing the foundation and installing proper drainage. If a prospective customer wants get the heck out of Dodge and pass this problem on to the next person, then oftentimes they’ll pass on a big, expensive project (but this usually comes back to bite them when they try and sell the house). 

Ok, now that we have that out of the way let’s talk costs … 

Foundation repair and replacement costs in the Bay Area are primarily driven by the lineal footage of the foundations, but also by things such as access, exterior items next to the foundation that need to be removed and replaced to do the work (such as patios or stairs), and most importantly by the height of the foundations.  

Access to the site can also be an issue. If it is up on a hill 50 steps from the street the work can be much more difficult, resulting in more labor hours and a higher estimate.  If you have basement walls vs a crawlspace, the height of the foundations will be another cost driver. A 6’ wall will cost 3x or so what a 2’ foundation on a level lot will cost.  

In real dollars, a simple foundation replacement for a small house in the flats will typically be $30,000 – 40,000, where a larger house in the hills with a developed basement and large foundation retaining walls could be as much as $200,000.  

As most genealogists would tell you, “it’s all relative”.  But you should be aware of these factors when considering the prices you are being given for this work.  And your contractor should be able to give you a sense of how these costs are derived. If he/she can’t, that’s a big red flag.

To generalize, a large percentage of foundation projects we do fall into the $40,000 – $60,000 range, but again there are a lot of factors.

Next, let’s talk drainage … 

Drainage Costs 

The type of drainage, its depth and location are key issues driving drainage cost. Due to the substantial presence of groundwater and the need for French Drains as well of downspout drainage, I have a tendency to recommend both elements as a part of most of my drainage quotes (unless there is an obvious surface only water problem).  

From experience we have learned that partial systems often fail due to water re-routing itself over time (that’s a whole different discussion), or inadequate depth of the work or improper waterproofing and poor detailing of the membrane system and piping.

French drains need to be installed below the lowest floor elevations of where the water is getting in to provide a safe long-term solution. Depending upon whether this drainage is around the entire house, or in the crawlspace and around the house, it can vary from 3’ to occasionally 10’-12’ deep in extreme cases (see our gallery at the bottom of this page for some examples).

With deeper drainage work we are required to do shoring and other OSHA approved methods for providing safety in deep trenches. This requires specialized equipment, such as aluminum trench shoring, and specialized training. Not all contractors have this in place, putting their employees and you the client at risk.

And as with foundations, drainage project costs are determined by depth, access, exterior elements that need to be removed and replaced, etc.  What often gets missed, but plays a big role in whether or not to do this work, is the current condition of the foundation.  

If the foundation is in fair condition or better, and if it could get a 20-40-year reprieve on its lifespan with good drainage rather than needing to replace in it a much nearer term without drainage, than the cost of good drainage is a great investment. 

So how much do drainage projects cost? 

As a general range, houses of small to mid-size with short crawlspaces and mostly dirt around them average around $35,000 for complete drainage systems.  Houses with full basements and stairs and patios that need to be removed and repaired can run up to $80,000, with drainage 8’ deep all around.  

As is the case with foundations, jobs on hillsides can be substantially more time-consuming, leading to additional cost. Most drainage systems are hand-dug, since they need to be placed adjacent to the house foundations so that waterproofing can be effective. Small electric jackhammers are the tools of choice, but the work is labor-intensive, usually requires a large crew, and involves removing huge amounts of soil (30-50 tons of soil removed is not unusual in a drainage project).

But as with foundations, whoever is bidding the work should be able to explain how the cost is generated.  

Sometimes the amount of items surrounding the perimeter of the building can be substantial, with removal and replacement costing as much as the drainage work itself. In the 80K example above, we needed to replace a substantial brick over concrete staircase and landing, which is 15K of that project cost, along with portions of the rear patio.

If the contractor knows what they are doing and is honest, there should be a reasonable explanation as to how the pricing is arrived at that should make sense to you as a homeowner. If a contractor isn’t able to help you understand why a project costs what it does and explain what they’re going to do for your (large) investment in your home, then it’s time to look elsewhere. 

Wrap Up 

At the risk of sounding like a crazy contractor, I want you to know one very important fact:

I don’t care if I get your job. 

What I do care about is working with homeowners who are willing to do what it takes to implement a long-term solution to foundation and drainage issues. 

I don’t want to come back and fix your job 5 years from now because it didn’t last.  

This is particularly true with drainage, because drainage patterns change and partial solutions often prove to be ineffective over time as water will re-route itself as ground conditions change and will lead to other water issues where they weren’t previously.

With drainage and foundation work though, choose your contractor wisely. Ask questions. Talk to other clients of theirs who had similar issues. And most importantly, make sure they’ve done this type of work before (a lot of it)

If you have a foundation/drainage project and you live in Berkeley, Oakland, Piedmont, or Alameda, fill out our Estimate Request form and let’s see if we’re the right fit for your job. 

If you are getting a lot of different answers and getting confused as to what to do, it is generally because the contractors don’t know the answers and are guessing. Most structural repairs are done by General Contractors without substantial experience or knowledge in this area. 90% of the jobs I look at generally have one way to do them right

Do I Need a New Foundation?

Most clients have no knowledge about their foundation and its condition until they begin to notice problems inside their homes- generally settlement cracks, sticking doors and sloping floors are indicators that something is amiss.

Though there is no cut and dry formula to show when a foundation needs to be replaced, there are a number of indicators which when looked at together should point the direction one way or another.

1. Are there drainage issues?

Drainage is the #1 culprit, and leads to settlement, cracking, and deterioration of concrete. Older concrete is somewhat porous, and water will soak into the material causing it to deteriorate. Since most older homes have nonexistent or improperly installed drainage systems, it is important to have the drainage issues addressed- either as part of the foundation work, or if the foundation is in decent condition to avoid an expensive foundation replacement project in the short term.

2. Is the concrete deteriorating?

By poking around with a screwdriver, we can see how intact the concrete is. Often concrete with lots of sand in the mix that has been subjected to drainage issues will be so soft it can be pulled apart with your fingers. This condition can be of major concern, as this concrete has very little strength and could liquefy in an earthquake. The harder the material the better. Appearances can be deceiving. Some of the ugliest concrete with lots of rocks and voids can be quite strong and is less of a concern.

3. Are there cracks?

A few cracks in older foundations is expected, but lots of cracks, especially one’s that are ¼” or larger can be problematic. Since older foundations typically do not have rebar in them, once large cracks occur the concrete can separate into sections that can rotate or settle independently from one another, causing settlement or shifting in the house above.

4. Is there rebar?

Most homes built before 1930 or so do not have steel reinforcement in them. Rebar helps to strengthen the concrete and hold it together in the event of cracking from settlement or earthquakes- cracks can still develop, but they remain hairline and don’t pull apart. The modern foundations we build have at least 5 pieces of rebar running horizontally, and verticals every 12” so they are heavily reinforced.

5. Depth and location of the concrete.

Often older foundations are not of sufficient dimensions to work effectively. If the footings are not at least a foot or more below the grade level they will be subject more to movement in expansive soils and drainage issues. If they are not 6” or more above grade there can be water issues at the framing level causing dry rot issues above. And if the soil is excavated on the interior of the basement or crawlspace too close to the foundations or if the footings are functioning as retaining walls and they are not designed properly they may settle or move, and they may create drainage issues leading to more settlement.

6. How old is the concrete?

Concrete from the early 1900’s that is still in place in older foundations is often in poor condition. Since most of the homes we work on in the East Bay were built between 1900 and 1930 this would definitely apply to them. Again, drainage, lack of rebar, improper dimensions, cracks etc. are much more pronounced in older foundations.

When all of these elements are looked at together, it is easier to get a sense of how your foundation is performing in these key areas. In many situations, where I give the foundation an overall score of 1-3 on a scale of 1-10 the need to replace is fairly obvious. In the 4-5 area it often becomes a more difficult question, where the client needs to consider their resources, how long they plan on remaining in the home, etc. If the foundation is in fair condition but in need of drainage work which might add another 20-30 years to its lifespan, that is often a reasonable alternative course of work. When the condition is poor, however, it generally does not make sense to do a drainage only project, since that work would need to be torn out and redone sooner rather than later as part of an inevitable foundation replacement.

Water is the REAL ENEMY for most homeowners!

The bottom line is that water is the main culprit implicated in most of the damage created to the exterior of your home, and can lead to interior damage as well. Maintenance problems such as chipping paint and damaged trim, poor flashing details around windows, decks, porches and doors, a roof which is leaking or needs replacement, or the lack of a proper drainage system around the home will all lead to potential problems when water comes into contact with your residence. Rainfall and underground water sources such as creeks and springs, a high water table, irrigation systems, leaking water lines or broken or disconnected drain lines- all of these water sources can wreck havoc on your home. Lets discuss how the different components of your homes exterior are affected.

The Foundation
Many of the older homes in our area have foundations that are in poor condition.

But this is not merely a function of the age of the concrete. Since most of the foundations were installed without drainage systems moisture in the ground adjacent to them, whether from rainwater or subterranean water sources, is causing them to deteriorate. Concrete becomes porous over time, and the water will saturate the interior of the concrete and cause it to break down. Water in the soil adjacent to and under the foundation, in conjunction with the expansive clay soils present on most of our properties, will cause the foundation to move as the soil shrinks and expands between wet and dry periods. Since older concrete is generally unreinforced it can settle unevenly causing it to crack, allowing more water to enter causing settlement. This often appears as cracks in walls, ceilings, and around doors and windows, along with sloping floors. Installing proper drainage will help alleviate these types of problems.

Exterior Walls
In older homes the stucco was often brought all the way to the ground. Since there are boards behind the stucco that were in contact with the soil, this gives termites access from the ground. When the paint and caulking are not maintained water can get in around doors and windows, leading to dryrot. Poor flashing details around porches, decks and roofs and leaking gutters and downspouts can allow water into the building as well, and termites love warm moist spaces. Foundations should always be at least 6”-8” above the soil level to prevent termites from entering at the base of the exterior walls. Foundations that are in poor condition should be replaced with taller, steel-reinforced footings. For foundations in better shape, concrete termite curbs can be installed at the outside of the building to create this clearance, and they are a more reasonable alternative to replacement. Painting and caulking should be properly maintained and trim should be repaired or replaced if damaged. Gutters and downspouts should be repaired if they are leaking, and they should be properly sloped to drain properly, flashed and kept clean to make sure they don’t leak into the exterior walls.

Interior Damage
When your foundations move for the reasons described above, this can lead to cracking and settlement on the interior walls and ceilings, doors and windows that stick or won’t close, etc. Sloping floors reflect foundation settlement or damage. By correcting the moisture problems first the interior damage should be minimized, at which point it will be appropriate to undertake repairs.

In summary, water is often the main factor leading to a large variety of structural repairs. Soil problems, earthquakes, and poor construction- these can also cause damage, but they are less common. Water is a subtle culprit that affects many older homes over an extended time frame, increasing with the age of the homes foundation. The sooner the maintenance issues can be corrected, the less they will affect the structure as a whole and the lower the ultimate cost of repairs will be.