How Many Blocks Do You Need? A Simple Guide to Estimating for Your Wall
Start with the wall area
Working out your block order only takes a few minutes. Measure the length and the height of the wall in metres and multiply them together. That gives you the wall area in square metres. Subtract any doors and windows.
Blocks per square metre
A standard hollow concrete block has a face of about 390 x 190mm. Once you allow for the mortar joint, that works out to roughly 12.5 blocks per square metre of wall.
A worked example
A boundary wall 10m long and 2.4m high:
- Area: 10 x 2.4 = 24 square metres
- Blocks: 24 x 12.5 = 300 blocks
- Add 10 percent for breakage and cuts: 330 blocks
If the wall will be two skins thick, double the number.
Which block: M90, M140 or M190?
The number in the name is the thickness of the block in millimetres.
- M90 is the thinnest and is used for light internal partition walls.
- M140 suits internal walls and many single-storey applications.
- M190 is the heavier-duty block commonly used for external, boundary and load-bearing walls.
The blocks we stock are 14MPa. If you are building something structural, always follow your engineer’s or architect’s specification.
View the blocks and bricks range for current prices.
Do not forget the mortar
You will also need cement and building sand for the mortar joints. Our sand, stone and cement range covers PPC cement in 32.5 and 42.5 and a choice of sands.
Tips to avoid running short
- Order everything in one go so the blocks come from the same batch and match in colour.
- Keep blocks off wet ground and cover them if rain is forecast.
- Always allow 5 to 10 percent for wastage; a few extra blocks cost far less than a second delivery.
Send us your measurements and we will help you confirm the numbers.
Add comment