Most of the time we use wooden formwork for constructing grade beam. In this post, we’ll see, how to calculate the wooden formwork for grade beam.

First we need to know **what is grade Beam?**

Grade beam is a sub-structure of any structure which is normally built on short column. Grade beam is also called *tie beam*.

You can use different types of shutter materials for the foomwork of grade beam. Such as steel shutter materials and *wooden shutter materials*.

When shutter materials are used to make a concrete form than it is called concrete formwork.

## How to Calculate Wooden Formwork for Grade Beam?

Before calculating the wooden formwork, you need to know how the grade beam will be constructed?

Grade beam can be constructed *directly on the ground *or *above from the ground*.

If the grade beam is constructed directly on the ground then you don’t need to calculate the shutter materials for the bottom of the beam. In that case, a brick flat soling is done on the compacted soil and then the formwork is fixed with the brick flat soling for constructing the grade beam.

But, if the grade beam is constructed above the ground then you need to calculate the shutter materials for bottom side of the beam.

We will calculate the formwork for both case.

So, let’s begin calculating the wooden formwork for a grade beam. The details of the grade beam is given below.

**Grade beam details:**

- Size – 10″ x 12″
- Length – 14′

**Required shutter materials for the formwork of the grade beam:**

- 1½” thick wooden plank
- 2″ x 3″ wooden button

So, we need to calculate the above two shutter materials for the formwork of grade beam.

### Calculating wooden plank:

Required 1*½” wooden plank* for one side of the grade beam –

- Length of grade beam: 14′
- Height of grade beam: 1′

So, Volume of wooden plank for the formwork of one side of the grade beam is,

= 14′-0″ x 1′-1″ (1″ extra height for jointing) x 1½”

= 1.90 cubic feet.

For another side of the grade beam, you’ll require the same quantity of wooden plank. That is, **1.90 cubic feet**.

Total required volume of 1½” wooden plank is,

= 1.90 x 2

= 3.80 cubic feet.

If the grade beam is built directly on the ground then you’ll need this quantity of *1½” wooden plank* for the formwork of the beam.

But, if you want to build the grade beam above the ground then you’ll require more wooden plank for the formwork of the **bottom side** of grade beam.

So, let’s calculate the shutter materials for the formwork of grade beam bottom.

- Length of grade beam: 14′-0″
- Width of grade beam: 10″

So, required **wooden plank** for the bottom of grade beam is,

= 14′-0″ x 10″ x 1½”

= 1.46 cubic feet.

In this case, total required wooden plank for the formwork of grade beam is,

= 3.80 + 1.46

= 5.26 cubic feet.

*Now let’s calculate 2″ x 3″ wooden button.*

### Calculating 2″ x 3″ wooden button for the formwork of the grade beam

Wooden button is placed 2′ center to centre distance.

As our grade beam is 14′ long, so the required number of wooden button for one side of the beam is,

= 14/2 + 1

= 8 nos

The length of a wooden button is 1½’ as our beam is 1′ hight.

So, volume of 2″ x 3″ wooden button for one side of the grade beam is,

= 8 x 1½’ x 2″ x 3″

= 0.50 cubic feet.

For both side of the grade beam, required button is,

= 2 x 0.50 = 1.0 cft.

If your grade beam will be built above ground, then you’ll also need wooden button for the bottom side of the beam.

So, required wooden button for the bottom side of the grade beam is,

= 8 x 1½’ x 2″ x 3″

= 0.50 cubic feet.

**Summary:**

*If the grade beam is built on ground –*

**1½” wooden plank:**3.80 cubic feet**2″ x 3″ wooden button:**1.0 cubic feet

*If the grade beam is built above ground (shutter for bottom side of the beam will be added) –*

**1½” wooden plank:**5.26 cubic feet**2″ x 3″ wooden button:**1.50 cubic feet

**Conclusion:**

If you don’t use wooden button for supporting the grade beam, then only the above calculated wooden shutter materials will be required for the formwork of the beam. But, if you want to use wooden button for supporting purpose also then you need to calculate those for the formwork of the grade beam.

When you order for wooden shutter materials, always add extra 5% with the calculated quantity.

*Say Something*

*How do you calculate wooden formwork for grade Beam? Please share in comments…*

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