Choosing the right length of spirit level can be tricky with so many choices available but with a little research you will be able to make the right choice of level for the right job.
To help you let’s take a look at the different spirit level lengths and which one is best for you.
Types Of Spirit Levels
There are many makes and types of spirit or bubble level available for tradesmen. The one that you choose should be the most appropriate for the job you are doing.
An I-beam level is shaped like a capital I, or a capital H when on its side. They have two horizontal planes called flanges and one vertical plane called the web.
I-beam levels are very popular spirit levels as they are lightweight, robust and relatively inexpensive.
Box beam levels (simple known as box levels) are so called because their profile resembles a rectangular box.
A box level has two short sides and two long sides which gives it greater strength and durability. Many box beam levels have integrated hand grips for better stability.
Torpedo levels are a smaller type of spirit level and suitable for small or tight spaces.
They will typically be made of metal or plastic and have three vials for measuring level, plumb and sometimes 45 degree angles.
There are other types of spirit level like pocket levels which are small enough to fit in your pants pocket and post levels.
A post level is a unique type of level that wraps around a post to measure the level and plumb of the post.
Line levels are a type of spirit level that attach to a tightly pulled string between two points to find level ground.
They are a cheaper alternative to laser levels, which produce a laser line level on the vertical and horizontal axis.
How To Choose The Right Spirit Level
The right spirit level for you will depend on what type of work you will be doing and the kind of measurements that you will need to take.
For those working on large construction sites a longer level will be more appropriate as the longer the level the more accurate the measurements will be.
A carpenter’s level will usually be a box beam level and come in a variety of lengths including 24 inches, 48 inches, 72 inches and 96 inches.
They will typically have three vials, two vertical and one horizontal.
A new shape of level from Stabila is the R frame level. This has a five chamber R shaped profile that is exceptionally stable and robust.
Unlike a rectangular box beam level the R-beam level won’t topple over in use thanks to its extra wide base.
This model comes in lengths from 24 inches up to 96 inches, so there is a size for most jobs, from site construction to DIY.
Floor screeding levels need to be long, tough and have two hand grips for better stability and accuracy. These heavy-duty spirit levels come in lengths from 24 inches up to 78 inches.
A torpedo level is small, compact and ideal for tight or cramped spaces such as under a kitchen sink or attic space where a longer level would be impractical and difficult to use.
The right length of spirit level for you will depend on the type of work you are doing and where you will be doing it.
Longer levels are better for jobs such as laying paving slabs, screeding floors or checking rafter levels on the roof.
Some levels even come with magnets to connect to metal surfaces hands-free.
Smaller levels are better suited for installing sanitary ware, tiling, and working in tight spaces. Think about the work you do and choose a spirit level that will work best for you.
Using A Spirit Level
To get the right length spirit level for the work you want to do it is important to understand the best way to use a spirit level and how to get the most out of this tool.
A basic but important step in using a spirit or bubble level is to make sure it is clean and free of any debris before using it.
Anything that is stuck to the measuring surface of the level will result in an inaccurate measurement.
Place the spirit level against the surface that you are checking. For a horizontal surface you will be measuring the level or how parallel the surface is to the earth.
On a vertical surface you are checking that it is plumb or perpendicular to the earth.
The spirit level vials will have a bubble, which should be in the center of the tube between the two marker lines. This means that the surface is either level or plumb.
If the bubble is to the right or left of the center of the vial this means that there is a corresponding gradient on the surface you are measuring. Complete the same process until the bubble levels are equal.
Longer spirit levels give a greater degree of accuracy as they measure the level or plumb over a greater distance.
Reading A Spirit Level
To correctly read a spirit level you should be able to clearly see the bubble within the vial.
Good quality levels have strong acrylic glass tubes which resist scratching, fogging or breaks so that they have good readability.
Place it on the surface you are measuring and check the location of the bubble within the vial. For horizontal levels, if the bubble is between the two marker lines, the surface is level.
If it is to the right of the markers, then the surface slopes downward right to left. If the bubble is to the left of the center markers, the surface is sloping downward left to right.
To check whether a vertical surface is plumb, rest the bottom edge of the level flat against the surface and read the vial that is now parallel to the ground.
If the bubble is off center then the surface is out of alignment and will need to be adjusted accordingly.
Longer levels have a greater degree of accuracy, and you should read the vial that is closest to you for an accurate reading.
Checking A Spirit Level For Accuracy
Regardless of the length of your level it is important to check that it is accurate.
To check the horizontal accuracy, place the level on a flat surface and make a note of where the bubble is in the vial, it does not matter if it’s not in the center at this point. You’re checking the level, not the surface.
Now rotate the level horizontally 180 degrees and place back in the same place as the first reading.
The bubble should be in the exact same position if the level is accurate. If it is in a different position then the level is not accurate.
To test plumb accuracy perform the same test against a vertical surface.
The rule for picking the right length spirit level will be to consider the job that it will be required for.
Longer levels give greater accuracy but are not practical for smaller jobs. Torpedo levels are great for some jobs like plumbing but will not be much use to a bricklayer.
So consider the job that you need the level for and pick the most appropriate one.