A good alignment system is essential for any ICF installation because it supports the walls to prevent failure and ensures straight, plumb walls. In addition, any time a worker’s feet are more than 6’ off the ground, back bracing is required by OSHA.
How Alignment Systems Work
Alignment systems work in the following three ways:
- They align the walls to within a tolerable level before the concrete is poured.
- They allow you to plumb the walls immediately after concrete is poured.
- They support the poured walls as they cure which protects against wind and other lateral loads until the concrete has gained enough strength to stand alone.
Metal vs. Wood Bracing
Metal braces are your best option to ensure the straightest wall possible. They offer a higher level of consistency since wood itself is not always straight, which can affect the wall. They are easy to use and can be installed much more quickly than wood bracing. Metal systems also have a much longer life expectancy than wood since they can be used over and over again. In addition, adjustments can be made easily after the concrete is poured with metal bracing. With wood bracing this can be difficult and dangerous.
Recommended Practices for Installation
- Install bracing after the first three courses are stacked.
- Install braces as follows:
- Along all wall segments at a maximum of 6ft apart.
- Within 2ft of a corner, on each side.
- At the edge of every door and window opening on each side.
- On all three sides of a stub wall.
- For t-walls install two kicker braces on the outside (top) of the T. This is because t-joints tend to bulge due to the pressure from concrete in the leg (bottom) of the T.
- Secure the alignment channels with at least one screw in each course of block. Alternatively, use the optional block straps which are attached to two webs in every other course of block.
- Make adjustments as you go along, do not wait until you are finished stacking.
- String-line the top of the wall in conjunction with the alignment, to ensure straightness.
- When in doubt, brace it out!
If you are new to ICF it is worth the small investment to have a seasoned professional do a pre-pour inspection.
Plumbing Walls
Plumbing the walls is one of the very last things to be done on an ICF project. Always stack corners to plumb but intentionally lean wall segments inward 1/4” towards the bracing. Since bracing is typically installed on the inside of the walls only, this is done incase the wall bulges towards the bracing. It is much easier to push a concrete wall outward rather than pull it inward.
Please let us know if you have any useful tips and tricks!