Proper inspection is must, to control the quality of a building during construction. If you have a handy inspection checklist during checking every part of a building, it’ll save your time and you won’t forget any point to check.
In my personal experience, I noticed that if I check anything in a building construction project without any checklist, I always forget to check something. When I sit down at my desk after completing checking, I always remember, oh! I forget that point to check.
I just made different checklists for different work phases of building construction and save it on my mobile. When I go for checking anything in building construction I just open the related checklist on mobile and check the things based on that checklist.
In this post, I’ll share an Inspection Checklist for grade beam.
What is grade beam?
Grade beam is built on short column. It can be constructed on the ground or above the ground. It works as a normal beam.
Inspection checklist for grade beam
Before pouring concrete into the grade beam, you should check the Grade Beam. The question is what to check?
You need to check two things. One is shuttering and another is reinforcement
Inspection checklist for grade beam shuttering
Check the following things on grade beam shuttering –
Shutter Strength: Check the strength of grade beam shutter whether it is capable to withstand against a load of concrete.
If you are using wooden shutter for grade beam formwork (we normally use wooden shutter for grade beam), then the thickness of wooden plank should be 1½”.
Waterproofness of grade beam form: Check the waterproofness of the formwork of grade beam. We normally use a thin metal sheet for this purpose.
The thin metal sheet is fixed on the wood joints by nail to make the formwork waterproof. Check all the joints of the wooden plank are covered with a thin metal sheet.
Check the size of grade beam form: Check the inside measurement of the grade beam form. You’ll find the grade beam size in the structural drawing.
Suppose, the grade beam size is shown in the drawing as 10” x 18”. That means, the breath of grade beam is 10” and the height of grade beam is 18”.
So, the inside dimension of grade beam formwork should be 10” x 18”.
Check supports for grade beam formwork: When you construct a grade beam directly on the ground, you don’t need to provide support at the bottom of the grade beam. In that case, a brick flat soling is made below the grade beam. That brick flat soling will support your grade beam.
But, if you need to construct the grade beam above the ground, you need to provide support at the Bottom side of the beam.
Whether you construct the grade beam on the ground or above ground, you need to give support to both sides of the form.
The spacing of the support should not be more than 2 foot.
So, check that there is at least one support within 2 feet distance.
Check the plumb of side shutter: Both sides of the grade beam should be truly vertical. For this, you need to check the plumb for both sides of the formwork. Plumb should be pointed at the inside of the form.
But, one thing. If you check the breath of the grade beam at bottom and top of the beam then you don’t need to check the plumb. I found it very useful.
Check the placement of grade beam: Finally you need to check the placement of grade beams.
To check the placement, you’ll need the “Grade beam layout” drawing of the beam.
You can check the placement of grade beam visually. You just need to check the placement of grade beams with reference to columns. See the “grade beam layout” drawing – which side of a column the grade beam is placed. Now check the formwork is placed as shown in the drawing.
Okay. We’ve just finished checking the formwork of grade beam. Now we will check the reinforcement of the grade beam.
Inspection checklist for grade beam reinforcement
To check the reinforcement of grade beam you need a drawing sheet – “reinforcement details of grade beam”.
Check reinforcement of grade beam: To check the reinforcement of a grade beam, you need to check the number and size of the following bars as specified in the drawing –
Top bar – The Top bar is placed at the top of the beam. Check the number and size of the top bar as specified in the drawing.
Bottom bar – the Bottom bar is placed at the bottom of grade beam. Check the number and size of the bottom bar as shown in the drawing.
Extra Top bar – Extra Top bar is place placed on the support. Check the number and size of an extra top bar as per drawing. Also, check the length of an extra top bar as shown in the drawing.
Extra bottom bar – The Extra bottom bar is placed at the bottom of grade beam. Check the number and size of the extra bottom bar as specified in the drawing. Also, check the distance between the end of extra bottom bar and support. This distance is normally shown in the drawing.
Stirrup – Check the size and spacing of stirrups as specified in the drawing. Also, check the stirrups aren’t twisted. Those should be truly straight with the cross-section of the grade beam.
Check hook of reinforcing bar: Hook should be provided as suggested by the structural engineer in the structural drawing.
Normally, structural engineers suggest providing the hooks at both ends of the top and bottom longitudinal bars and stirrups.
So, check hooks are provided at both ends of top and bottom bars.
The angle of stirrup’s hook is normally 135 degree. Check, it is provided correctly. Workers always tend to provide a stirrup hook at 90 degrees. So check this properly.
Hooks of stirrups should be placed alternatively on both sides of the beam. That means, if one stirrup hook is placed at right side of the beam then next stirrup hook should be placed at the left side of the beam.
Check lap length of the bars: Sometimes we need to provide lap in reinforcing bar if the grade beam is longer than the bar length (one bar length is about 40 feet).
Check the lap length is accurate. You will find the required lap length for different sizes of bars in the “general note sheet” of structural drawing.
So, check the lap length is maintained as suggested in the structural drawing.
Check the lap placement: For top bar, the lap is provided in the middle half portion of the beam. And, for bottom bar, it is normally provided on the support generall rule).
So check the placement of lap for both top and bottom bar if they are placed properly.
Check concrete clear cover: Required concrete clear cover for different structural member is shown in the structural drawing – either in the “general note sheet” or in the “reinforcement detailing of grade beam” sheet.
Check the specified Concrete Clear cover is maintained all around the beam.
We normally maintain the concrete clear cover of grade beam by providing “CC Cover Block”. Check sufficient “cover block” is provided to maintain concrete clear cover for reinforcement.
Cover Blocks are Normally provided at 2 feet distance. So Check there is at least one cover block within 2 feet.
Check Spacer: If the grade beam has double layer reinforcing bar than you need to maintain 1” gap between the layers.
To maintain this gap a spacer is provided between the layers. We normally use 25mmø bar for this purpose.
Check spacers are provided to maintain 1” gap between layers.
If you found anything unusual during checking the grade beam, go for correcting it. If everything is found correct, you can start to cast concrete.
Did I miss any point in this inspection checklist? Please share in the comment below …