BUILDING FOUNDATION - In order to be able to start the foundation, the building pad needs to be complete. Dirt needs to be compacted and rough graded to the correct elevation. The batter boards and string lines will allow you to get a true picture of the footprint. The batter boards and string lines will allow you to get a true picture of the footprint of the house and finish floor elevation. The foundation forms can be wood as in most residential construction or metal as in commercial construction. Once the forms are set, they need to be braced off in order to prevent the concrete from pushing the forms out. Concrete is one of the main building products used in the construction of a house. Depending on where the concrete is used in the construction process, it can become a very critical factor in the overall structural strength of the house.

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Building Foundation

constructionjargon.com

Foundation - First Task
The location of the foundation is determined by the site survey or plot plan.

The plot plan will show all property line setbacks, dimensions, easements, and any other normally determined by flood plane restrictions or city and county codes.

The surveyor can provide a marker or benchmark that serves restrictions that might be required.

Another important item required for the foundation is the elevation of the foundation.

The elevation is normally determined by flood plane restrictions or city and county codes.

The surveyor can provide a marker or benchmark that serves as a reference to establish the finish floor elevation (FFE).

In order to be able to start the foundation, the building pad needs to be complete.

If fill dirt is required, it needs to be compacted and rough graded to the correct elevation Once the pad is complete and the corners established, batter boards can be put up.

The batter boards and string lines will allow you to get a true picture of the footprint.  

Once the pad is complete and the of the house and finish floor elevation. After the string lines are checked for correct dimensions and corners established, batter boards can be put up.

The batter boards and string lines will allow you to get a true picture of the footprint of the house and finish floor elevation.

After the string lines are checked for correct dimensions and being square, you will be ready to start putting up forms and digging footings.

The foundation forms can be wood as in most residential construction or metal as in commercial construction.

Once the forms are set, they need to be braced off in order to prevent the concrete from pushing the forms out.

After the foundation forms are set and braced, the underground plumbing can be installed. The plumber can use the form boards to lay out the position of the plumbing walls and pull string lines.

With the plumbing wall lines in place, the plumber can dig the plumbing ditches and be sure that the plumbing is installed correctly.

After the plumbing is installed, the ditches should be left uncovered until inspected by county or city
inspectors.

Sanitary lines are checked for slope and for leaks. Sanitary lines should have at least a 1/4 inch slope per foot.

The sewer lines are checked for leaks by using a ten foot stack test.

The stack test is accomplished by extending the main vent stack, usually a 3 inch PVC vent up ten feet.

The whole house sewer system is then filled with water up to the top of the ten foot vent stack. All the underground plumbing connections are then checked for leaks.

Concrete is one of the main building products used in the construction of a house. Depending on where the concrete is used in the construction process, it can become a very critical factor in the overall structural strength of the house.

Just because the concrete comes premixed in the concrete truck does not mean that the concrete is always good.

In normal residential concrete, the first conversations might be with the concrete company's outside sales person.

The size of the foundation and how much concrete will be required are usually the first questions to be answered.

The quantity of concrete is expressed in "yards". One cubic yard of concrete is equal to
twenty-seven cubic feet of concrete.

An example would be if there was a hole three feet wide, three feet long, and three feet deep it would require one yard of concrete to fill the hole.

Another value that is used when pouring sidewalks and driveways is that a yard of concrete will cover eighty one square feet of area (driveway or sidewalk) when the concrete is four inches thick.

The next issue discussed might be the strength of the concrete.

Years ago, the only strength concrete used in house foundations was 2000 psi (pounds per square inch) concrete. It's not unusual today to see builders pouring 3000 psi and 4000 psi concrete, depending on the size and complexity of the project.

Some of the larger homes are designed by an architect and might require a structural engineer. The structural engineer might require mix designs from the concrete company for his approval.

The sales person might ask next what kind of "slump" is required. This is sometimes where the concrete subcontractor and the builder might try to reach a compromise.

The lower the slump the greater the strength but the harder the concrete is to work. The higher the slump the lesser strength but the easier
the concrete is to work.

When a structural engineer is involved, he might specify that the concrete is to be 3000 psi with a three to five-inch slump.

If this is specified, it is very important to stay within these limits do not allow anyone to add water to the mix on site without permission from the individual doing the testing.

If the concrete is being pumped, there are additives that can be added to the mix in order to
allow a higher slump but not jeopardize the strength of the concrete.

These additives can also be used in dry and windy climates to allow a wetter mix and hopefully prevent surface cracking due to the fast dehydration of the concrete.

If the concrete is tested, the slump might be checked every fifty yards and the cylinders might be taken at the same interval.

Concrete cylinders are taken and tested to verify the compressive strength of the cured concrete.

The cylinders are compressed and broke at specified intervals. A cylinder broke after 28 days should break at the designed strength or greater.

Also, usually the temperature of the concrete will be checked at this time. The temperature of the concrete might become more of a factor in the summer rather than the winter.

A rule of thumb might be that if the concrete temperature is above 95 degrees it is not acceptable to pour in the foundation or footings.

Sometimes a good starting point to monitor the temperature of the concrete in a truck is to check the ticket and see when the truck was loaded at the plant.

In warmer climates, the longer the concrete is in the truck the hotter the mix. In cooler climates the temperature might not be out of range but the time in the truck might become a factor.

Usually a rule of thumb might be that, if it has been forty five minutes to an hour since the truck was loaded, the load may have started setting up and might not be acceptable to use.

As you can see there are a few more things to consider in foundation concrete other than just pouring the concrete out of the truck.

As in most any other construction process, a little pre-planning and basic knowledge might prevent a major mistake that could cost a lost of time and money.

As stated previously, the foundation is one of the most important phases in the construction of a house. This phase will require you to be familiar with reading plans, dimensions, and formulas to determine quantities of required materials.

Some of the more common quantities will be expressed as length, width, depth, linear feet, board feet, square feet, cubic feet and cubic yards. All the materials in the foundation will be ordered and bought with one of these descriptions.

In order for you to be able to estimate and order materials correctly, there are certain formulas that can help you calculate the correct quantities of concrete.

The following formulas are ones that will be necessary in order to calculate and order the required material for your foundation.

Linear Feet is probably the simplest quantity to calculate. Lumber yards sometimes sell lumber by the linear foot which makes it easy to calculate the
cost per piece.

Linear feet = number of items X the item length
220- 2 x 4's lumber X 16 feet in length = 3520 linear feet

Lumber is one of the main items that might be bought by the linear foot for a foundation. If you dig footings, labor might be charged by the linear foot.

Board Feet will add two other dimensions to calculating the cost of materials. Lumber suppliers sometimes sell their lumber per thousand board feet.

A board foot is one linear foot of lumber - one foot wide - one inch thick. A 1x12 piece of pine which is 12 feet long will equal 12 board/feet.

In the same way a 2x6 piece of pine 12 feet long will equal 12 board/feet.

Board feet = Linear feet X ((thickness inches X width inches) / 12 inches)
(3520 linear feet of 2x4) X ((2-inches X 4 inches) / 12 inches) = 2347 Board Feet

Lumber may be sold by the board foot form the building supply. The board foot price will be expressed so much per thousand board feet.

Example: 2 x 6’s might be sold as 565.00 per M (Thousand board feet). This will equal .565 cents per board foot.

Square Feet is a simple process of multiplying the length X the width. You will need to know how many square feet there is in the foundation in order to estimate how much vapor barrier to buy and to determine how much the termite pre-treat will cost.

Square Feet = Length X Width

Cubic Feet adds one other dimension to square feet. This dimension is depth. Items that require you to know the amounts of cubic feet are fill dirt and concrete.

Concrete and fill dirt are both sold by the cubic yard. There is 27 cubic feet in a cubic yard of fill dirt and concrete.

Cubic Feet = Length X Width X depth

Cubic Yard is used to determine how yards of concrete or fill dirt might be needed for the job. There is 27 cubic feet in a cubic yard of fill dirt and
concrete.

Cubic Yard = Total Cubic Feet / 27 cubic feet

I have over thirty years experience in residential construction. I have managed projects from
one single family home to projects consisting of over four hundred homes. During the past
thirty years, my projects have demanded a knowledge of every aspect of construction including
site work, utilities, streets, playgrounds, club houses, swimming pools, and landscaping. I have
experienced the ups and downs of the industry and have probably heard every excuse there is
for not wanting to do a job a particular way. I always have had the philosophy that if I did not
know as much or more about the task being done than the sub doing the work, I would be at a
disadvantage. I have tried to put together some topics and articles that should help someone
not familiar with construction to get a better knowledge of particular tasks in the construction of
a home and be able to talk the talk during the process. The topics in this website are not
necessarily true for all parts of the country. The construction process will change depending on
soil conditions and climate. I appreciate your visit to my site and hope that your construction
experience is good.  

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