Foundation Settlement – When is it a problem?

With the exception of houses built on solid rock, ALL foundations settle over time. Fixing foundation is not uncommon but you should still consult a residential foundation contractor to help. A typical total foundation settlement range is up to approximately one inch. The alternative is to build on soil, which has a tendency to settle or in some cases, depending on soil type and moisture changes, heave over time. The purpose of a foundation is to allow the structure to settle evenly, or uniformly, versus differentially.

The question is “When does foundation settlement or movement become a problem?”

Foundation Problems Caused By Soil Expansion

Soil conditions directly affect how the foundation of your home settles over time. Poor water drainage can leave excessive water in the soil, with this exposure causing many types of soil and clay to expand. When expansive soils shrink and swell, it puts direct pressure on the foundation, causing cracks and water damage. Poor water drainage can be due to many factors, such as plant watering areas next to the foundation that are not diverted away from the house or areas that have not been sloped correctly to avoid excessive pools of water.

Too much standing water or moisture is not good for your home as it can cause foundation movement and cracks to appear in walls.

Differential Foundation Settlement Movement

Even though foundation settlement is to be expected, the purpose of a foundation system is to keep the framing on top of it as plumb and level as possible. Industry standard for a new construction building floor is +/- ½" out of level in a 20’ length. When one part of the foundation settles or heaves faster than another, which is referred to as differential settlement or movement, it creates distress in the framing. This can make it so that your house leans or tilts to one side, causing distress and cracking in the foundation.

Differential foundation movement can create problems. Windows and doors may bind and become inoperable. Drywall or plaster may crack and fall off the walls and ceiling, and floor coverings like tile and hardwood may buckle and bend. In more extreme instances, framing connections may be compromised and cause structural failure. To prevent this, foundation repair should be considered before it gets to that point.

Home Foundation Fixing Experts

Do you have problems with door and window operation, interior and/or exterior cracks in finishes, and sloping floors? These are just a few warning signs indicating that there may be a problem caused by excess differential foundation movement. If you notice these signs, it is best to have qualified residential foundation contractors assess the structure. A residential foundation contractor can determine if the movement is normal or if home foundation repair is necessary.

Give Versa Grade a call at 775-284-1964! We are happy to have one of our residential foundation contractors come out and take a look at your home and let you know if a foundation repair is needed. We will also advise you if a repair is not needed!

I Have Foundation Cracks – Should I Be Concerned?

Foundation cracks worry a lot of people. Home inspectors may tell you that they need to be repaired, and to consult with foundation repair contractors/residential foundation contractors. Home buyers may see problems that call for your foundation fixing but walk away from a potential transaction or ask for a reduction in the sales price. Truth is, most foundations have cracks. It is the type, size, and orientation of a crack(s) that determine whether or not there may be a problem.

How do cracks form?

From the moment concrete is placed, it begins to shrink via the hydration process. Extensive research has been conducted to evaluate why and where concrete tends to crack. As a result, several standards have been put into place to reduce, eliminate, or control the locations of cracking.

There are several external factors such as temperature (both ambient and concrete mix), water content, humidity, and placement practices that all play a role in how concrete performs.

Controlling the spread: fixing foundation

There are two common means of control done by our residential foundation contractors. The first, Expansion Joints, are designed to permit expansion and contraction of concrete masses. On the other hand, Control Joints are saw cuts or tooled joints in concrete sections to allow it to crack at specified locations. The addition of reinforcement in the pour, such as rebar, will also help curtail cracking.

However, in the end, most concrete pours crack during the curing process. The American Concrete Institute (ACI) spells out the technical aspects here, but the California Department of Transportation adopted an easier to read specification for concrete shrinkage. .05% - .08% for every 12’ feet. This works out to about the width of a dime every 12’.

Warning Signs of Foundation Problems

The question is: “Are the cracks in my foundation normal? Or do I have a foundation issue?”

“Hairline”, or small cracks, are typical in most foundations. They generally are vertical and are not offset. That is to say, that one side of the crack has not moved up or down, or in and out as opposed to the other side. They are also generally the same width from top to bottom. These types of cracks are generally considered normal and are usually of small concern. Water can get into these cracks, and if it freezes, can actually break off pieces of concrete making the crack bigger. The best way to address these cracks is to have residential foundation contractors seal them up with paint, caulk, or a variety of readily available sealers that will prevent water infiltration.

However, any crack wider than ¼” may be cause for concern and a need for fixing the foundation as it can allow for water infiltration. The type of crack is also important. Diagonal cracks & cracks that are wider on one end vs. the other may be a sign of movement. Cracks that are offset, or groups of several cracks are also likely a sign of distress. These types of cracks should be looked at by a professional to determine a cause and remediation. All structures settle over time. The purpose of a foundation is to allow the structure to settle as a unit at a slower rate. If you have foundation problems, you are likely to see interior sheetrock cracks, doors misaligned within the jamb, uneven floors, tile cracks, window frame separation, and even walls pulling away from the house.

To wrap up, here are some warning signs that will need to be evaluated by a foundation repair expert:

Any crack wider than 1/4"
Diagonal cracks
Cracks that are wider on one end versus the other
Cracks that are offset
Groups of several cracks
Interior sheetrock cracks
Doors misaligned
Uneven floors
Tile cracks
Window or door frame separation
Walls pulling away from the house

These can be signs of water infiltration, movement or distress in your foundation.

Versa Grade - Foundation Fixing Experts

In summary, concrete cracking can be the result of a poor batch of concrete, poor placement and/or curing methods, less than adequate installation of expansion and/or control joints, or the result of non-uniform foundation soils movement. Concrete cracking is generally classified as structural or non-structural. Structural cracking may require monitoring and potentially remediation, while non-structural cracking is mostly cosmetic in nature.

If you start to see threatening cracking in your foundation, give one of our residential foundation contractors a call at 775.284.1964 or send us an email! We will be happy to come out and take a look as your foundation crack repair experts!

5 Warning Signs You Need Foundation Repair

A structure does not have to be older to be in need of foundation repair. The need for fixing foundation can also be caused by construction, soils, and weather. The warning signs which indicate foundation problems are subtle. If ignored, it could turn into a bigger project down the road. It is crucial for your foundation to consult with residential foundation contractors.

Here are 5 warning signs your home or commercial building may need foundation repair.

Windows and doors stick: This is one of the most common signs of foundation problems. If your doors aren’t swinging freely or your windows are hard to open, it may be a sign that a foundation repair is needed.
You see cracks: Inspect your home or building for cracked interior or exterior walls. Plaster, dry wall, and even exterior brick and stucco may crack and your foundation will need fixing and repair.
There are gaps: Take a look at your base boards and crown molding. If you start to see gaps form or separation from the wall, foundation problems could be the cause. This also applies to gaps in caulking.
Areas of the floor are sinking: Sunken living rooms are intentionally sunken. But a sagging floor is another thing. If you notice a dip in your flooring when you are walking, you may have foundation problems and need to seek out someone that is an expert when it comes to fixing foundation.
The patio is uneven or separating: Patios and outdoor steps often separate from the home or building if foundation problems are present. Tilting of the concrete panels may also occur.

Foundation inspections from residential foundation contractors is an important step in maintaining your property. Foundation problems left uncorrected will get worse. It’s important to be aware of the warning signs and head off the need for fixing foundation issues in the future. Keep your eyes open and stay aware of the signs. If you notice any of them, give us a call. You will be grateful you did.

Call us. Our residential foundation contractors are here to help.

Stoker Project Basement Wall Repair 3/17/16

PROJECT DESCRIPTION

Residential homes around Reno Nevada built between the 1920’s -50’s were typically built with unfinished basements for food, coal, & dry storage. A fair amount of these basements were constructed with little or no reinforcing steel. It was not uncommon for the structures that did have reinforcement, to consist of old fence posts, bailing wire, or any other scrap iron a builder could find. Along with added square footage, basement level foundation systems also served as an added layer of protection for structures built on expansive soils. The practice was to support the structure on soils well below finished grade so seasonal moisture change (i.e. rain & snow / summertime drying) would not affect the foundation. The Stoker Project was an excellent example of this type of construction.

PROJECT HISTORY

Originally constructed in 1954, the Stoker Project was a single story structure built on a basement that extended under the entire footprint of the upper living area. The soils in the area are Alluvial Fan Deposits of Peavine Mountain and consist of gravely to sandy clayey silt with andesite fragments common. These soils are highly expansive and reactive to moisture content. Water intrusion in the basement had always been a problem for the owner, and over time, the swelling of the clays against the basement walls had pushed hard enough to break the walls and cause structural damage to the framing components. No reinforcing steel was observed in any of the concrete breaks, some as large as 1” in width. The rear wall of the basement had a large bow from top to bottom, and was pushing into the interior walls while pulling away from the upper level floor joists. Damage was significant enough to warrant the installation of temporary shoring supports until VersaGrade repair crews could arrive with fixing foundation solutions.

PROJECT DETAILS

VersaGrade was contacted by the Owner to help design the repair plan, & K2 Engineering was retained as the project engineer. The Owner had constructed a deck and hot tub enclosure along the wall in question that had taken quite a lot of time and effort. This added a surcharge to the wall which contributed to the walls failure and adjacent interior framing. Our goal for fixing the foundation was to support the wall in place without demolishing the deck or hot tub enclosure. As such, all construction operations took place inside the basement. Because reinforcing steel was not present, a whaler system needed to be installed to help distribute the lateral forces. Prior to the installation of the whaler, solid steel Ram Jack 1.5” square bar Helical Anchors were installed through the wall using a hand held torque drive motor. The mid points between the anchor installations were supported vertically by the installation of Fortress Stabilizations ™ – Carbon Fiber support straps. The straps were epoxied to the concrete wall, & Kevlar straps embedded into the epoxy. These Kevlar straps were then connected to the structure framing to prevent overturning of the wall. The final bracing came from the installation of the whaler that consisted of a 10” wide continuous steel channel bolted to the wall & tying the system together. Fixing foundation can be a long and difficult process and even though the space constraints were a challenge, the project was a total success. The wall had been stabilized, and the Owners hard work on his deck had been saved.

VersaGrade used the Ram Jack Portable Hydraulic Pump and 2.5K Hand Held Drive Motor for the anchor installations.

Total No. of Ram Jack 1.5” Square Bar Helical Anchors Installed: 5

J & J Nevada - Seismic Retrofit & Tenant Improvement with Micropiles

PROJECT DESCRIPTION:

J & J Nevada was a project involving a seismic retrofit and tenant improvement to an existing warehouse in Sparks, Nevada. Additional truck docks were required to be installed, changing the structural characteristics of the tilt up concrete building. The installation of a moment frame on the interior of the structure required some relatively high loads to be addressed in tension and compression at specific locations. VersaGrade was contacted early in the design phase to help determine the best foundation system to address these loads.

PROJECT HISTORY:

Originally built in 1979, the warehouse was constructed for General Motors Corporation as a parts distribution center. The 634,000 Square Foot facility included dozens of truck dock openings and an interior railroad spur for the unloading of train cars inside the building. The soils are predominately Alluvium of the Truckee Meadows, consisting of pebble to cobble sand, silty sand, and sandy silts overlain by scattered, well rounded volcanic & granitic cobbles. Due to the rocky nature of the site and limited soils investigations, VersaGrade concluded that the use of Micro Piles would be the best system to meet the required loads. Pile groups of 3-4 would be necessary to achieve the 140 Kip allowable loads at specific points along the perimeter foundation.

PROJECT DETAILS:

VersaGrade, Inc. was awarded the subcontract to install 40mm Contech Systems Micro Piles along with a custom Ram Jack bracketing system. K2 Structural Design & Ram Jack Engineering were contacted to help design the bracket that would carry a 35 kip allowable capacity (70 Kip Ultimate) in tension and compression for each pile. Each bracket was designed to work on shear strength alone, and attach directly to the tilt up panels themselves as there were no footings to attach to in some locations. Six each 7/8” diameter epoxy doweled bolts (per bracket) were used to secure the brackets to the face of the concrete tilt-up walls. A 5 ½” diameter x 8’ long steel guide sleeve was then inserted through the brackets and set to elevation. After bracket installations were complete, VersaGrade installed Contech 40/16 Micro Piles with a 4” carbide cutting bit down through each guide sleeve. The Micro Piles were installed to an average depth of 21’. One of the challenges of the project was higher than expected grout usage during the Micro Pile installation due to unconsolidated material and fissures. Some piles took in excess of 35 cubic feet of grout to complete.

VersaGrade used a Komatsu PC-160 Track-mounted hydraulic excavator with an Excavator Mount TEI 350 Rock Drill and ChemGrout CG600 Batching Plant for the Micro Pile installations.

Total No. of Contech Micro Piles and Ram Jack Custom Brackets installed: 14