G’day Distributors and Happy 2022!
Just a reminder that version 2.18.22.0 has recently been released.
Please download the update and clear the engineering cache in ACT.
I want to discuss some upcoming design improvements scheduled to be completed this quarter.
Next month, we will be rolling out new training videos in ACT. The plan is to feed these along the bottom of the ACT Start Page.
As you place new staff onto ACT, the training newsletters will start over for that particular person, and they won’t go away until they have been read.
This should greatly improve training people as there are a lot of design options that need to be clearly understood.
On a different topic, several of you have asked if we can make the “no cut for girts and sheeting” option as a default setting when placing windows and PA doors.
There is a good reason why we have not done this. In March we will be releasing diaphragm bracing in ACT.
This is where we utilise the shear load properties in the wall sheeting to reduce X bracing, which can provide a slightly better and cheaper design.
Before deciding on having the opening to be uncut, or cut to length purlins, consider the following:
1.Engineering is drawn and calcs are provided based on specific window locations. Technically if the door or window is moved, the engineering is voided.
If you think about a door, for example, that might be located 200mm from the end of the bay, then there is a support (in the form of a column) nearby and the loads only need to transfer a short distance. But if you decide to cut the girts on site to place that door in the middle of the bay where the supports are further away, then the load taken by the girts is mid-span, as opposed to at the edge of the bay, and the loads are significantly more and maybe to the point of failure.
2. ACT has diaphragm bracing planned to be available for use by the end of March this year. When we get it done, we will be able to calculate and use diaphragm bracing, which will replace strap bracing in part, or completely depending on the shed design. Diaphragm is based on using the sheets over a length of unobstructed sheeting. So imagine a 2 x 3m bay 6.0m long wall with a 1.2w window 200mm from one end, that effectively leaves 4.6m of sheeting we can use for diaphragm and the building would be designed based on that. If however the window is moved on site to the middle of the bay, the diaphragm length reduces to 3.9m. In effect, now the engineering has been voided as a result because potentially there is not enough bracing in the building.
3. Pricing – if you price all your buildings with girts not cut then you will have a higher price than someone who prices pre-cut girts to length. Given the Australian market generally prices no-cut girts, this could be an advantage.
4. ACT can use self-supporting doors and windows. As you can see from the US building below there is 2 PD doors, one with a frame (like Larnec) and one without. The one without the frame has the necessary engineering information/testing provided by the manufacturer to allow the girts to attach to the door frame which becomes a structural member of the building, the other one does not. So there is no need to cut girts on site or have additional components leftover if a frame is not needed. Whatever is on the engineering plans is what’s important.
5. If the doors are placed correctly, the builder on site does not need to cut them, that has to be an advantage. Given ACT allows you to see the x-bracing location, you can tell exactly how x-bracing will interact with any window or door frame.
6. If the default option is cut on site then diaphragm bracing cannot be used in the calculation.
Should we do things because everyone does, yes sometimes, but other times we should set ourselves apart and educate ourselves as to why we are doing it this way. Now I am not saying cutting or not cutting the girts is the right choice for you, but it’s good to have the options and consider everything before making that choice.
Best regards,
Chris Lynch
Managing Director
Cold Formed Building Systems Pty Ltd
