Standard details

The detail groups, two sheets

The panel elevation shows every piece, but it does not show how two pieces hold together. That lives in the details: the section through the wall base, the fit of the stud in the track, the nogging crossing the studs, the meeting of two walls, the board screw 10 mm from the edge.

In CalcSteel these drawings come from two buttons in the wall footer. Typicals builds the "Typical details" sheet: only the ones the project needs, each at its own scale, six per A3. Joints builds the "Joint details" sheet with one drawing per joint type (L1, L2, L3...) and the mark of each spot on the plans.

Both sheets are live, like the ones in LSF sheets: they store only the detail code and redraw from the model every time they open.

• 5: typicals on the 9x7 house sheet: DT1, DT21, DT22, DT27 and DT28
• 1:5 to 1:25: fixed scale of each typical, from the wall base to the board
• 6 per A3: the seventh goes to sheet 2, without repeating the six
• 5 joints: on the house joints sheet: L1, L2, L3, L6 and L9

The screenshots on this page come from the app, on the roll-formed 9x7 house (FRAMECAD F325iT, C 89x41 of 0.95).

What holds to what, group by group

The installer reads the panel in the elevation and the fixing in the detail. That is why the details are split the way the building is. The table shows what the app draws in the groups of the example house: base, wall and boards.

What lives on another page

The frame of each window at 1:20, the section through the header and the opening schedule come from the Details button (LSF sheets). The L and T joints spot by spot, with the marks on the plan, are in Connections panel. Here they appear only to close the group.

What is detailed in the design

Rafter and purlin, ridge, eave, hold-down, X bracing, double stud, header and sill as a typical, and the inner board stay off the typicals sheet. Those joints are detailed in the design, from the 3D with the purple button and from the machine file (Roll-former file).

What the standard asks on paper

NBR 16970-2:2022, the Brazilian standard for light steel framing design, lists the minimum content of an LSF structural design. Part 3, under development (2022 consultation), covers the interfaces: whatever touches the steel. Here we give only the item numbers; read the text in the standard.

Model finished first, details last

A typical only comes in if the project has what it shows. Requesting the sheet early gives an incomplete sheet, and requesting it again creates a sheet 2 with only what was missing. The order that gives the fewest sheets:

1. Close the model

Walls, joints, openings, noggings, roof and the market board layers. Each one switches on a typical.

2. Check in the 3D with the purple button

The purple button, "Show as the roll former makes it (swage, fit, dimple)", shows in the 3D or in the wall view the swage, the dimple and the half-moon cut of the roll former. The 3D is the truth: the detail must draw the same.

3. Joints, then Typicals

Joints places the L marks on the plan; the typicals give the rule that holds for every spot of the same type.

4. Black and white and PDF

The only toggle on the typicals sheet is black and white; the scale is fixed per detail. The PDF comes out as in LSF sheets.

The FRAMECAD rule of the example house

A roll-formed project is assembled by the machine. Every joint taught here is one of the documented FRAMECAD joints: fit of the stud in the track (DT27), overlap of the nogging (BQ, HT, SL) over the stud (DT28), angled fit of the web in the chord (DT29), L corner and T junction with one stud from each wall, without a box, and the truss with lipped chords, a half-moon cut at the heel and no plate. The only exception is the purlin lapped over the truss, which is not a machine joint.

The "Typical details" sheet

1. Select an LSF wall

Any one: the typical belongs to the project, not to the wall. The footer shows the six sheet buttons.

2. Click Typicals

The app reads what the project has, picks the typicals it needs that have a drawing, and creates an A3 with up to six, each at its own scale. The screen goes to Prints with the sheet open.

3. The model grew? Click again

When the model gains a piece that calls for another typical, the second click does not repeat the ones already on the sheet: it creates "Typical details, sheet 2" with only what was missing.

The wall base: DT1 and DT27

DT1 shows everything that is fixed and sealed at the base; DT27 shows the machine fit. Both use the project profile, with the same dimensions as the 3D, and the DT27 numbers are the same as in the roll-former CSV. On the joints sheet, L1 (anchor) and L2 (stud to track) mark each spot on the plan.

The nogging over the stud: DT28

Every wall nogging (the BQ blocking and the HT and SL tracks at the head and the sill) crosses the studs the same way: on the outside, lapped, with the stud swaged only within its band. DT28 draws that joint once, and it holds for every spot where a nogging crosses a stud. The position of each nogging is in the panel elevation (LSF sheets) and in the 3D.

How to read DT28

The drawing marks the stud, the swaged band, the web notch, the dimple and the nogging passing on the outside. The numbers are those of the roll-former file, the same as in the CSV (Roll-former file).

Checking in the 3D

Turn on the purple button, zoom in on a nogging and compare: the half-moon cut and the holes in the 3D fall where DT28 shows the swage. The strap that runs across the studs is in Straps and blocking.

The house joints sheet

With the wall selected, Joints creates the "Joint details" sheet: one drawing per type, drawn on a real wall (the note says which) and valid for every spot with the same mark on the plan. Its step by step is in Connections panel; here is what it showed for the house.

The scale drops one step when the drawings do not all fit on one sheet. That was the case for the house.

The truss at its support: the 3D and the machine

In the house, the roof comes from the Roof tool in plan: the two 7 m sides as gables, 30%, 600 mm eave, Generate. The box reports roof TL1 with 2 planes, the ridge 1.06 m above the wall top and 14 in-line trusses.

In a roll-formed project, the truss is a machine panel: lipped chords, a half-moon cut at the heel, screw holes and no plate. Its bearing on the top track is read in the 3D with the purple button, in the plane of the trusses.

The truss is a roll-formed truss, and the node of the web in the chord is DT29: with the roof generated, the project starts to call for this typical, and a new click on Typicals puts it on "Typical details, sheet 2". The dimensions of each piece, with the swage and the holes, come out in the roll-former file (Roll-former file). The purlins are lapped over the truss, the exception to the FRAMECAD rule (Recommendation).

OSB, fiber cement and gypsum: DT21 and DT22

The layers come from the project market (Market and catalog), and each board brings its fastener and its spacings. If the outer board has a custom name, outside the catalog, DT21 does not come out and says why.

Spacings in mm, observed in the Brazil market of the house.

Scale, trigger and numbers of each typical

Nothing here is typed on the sheet. The trigger is the model; the numbers come from the project market; the profile is the project's. The sheet only chooses black and white.

Truss, for DT29, is the wall lattice column and, in a roll-formed project, also the roof truss and the floor truss joist. The sheet also draws DT4 (strap and blocking, 1:10), DT11 (floor joist on the rim joist, stick-built project, 1:10), DT30 (floor truss joist on the track, 1:10) and DT15 (truss bearing on the track, stick-built project, 1:10), when the project has what they show and the market has their numbers.

• 6: typicals per A3; the seventh opens a new sheet
• 1 toggle: black and white; each typical's scale is fixed
• 0: designed screws: the fixing is the market rule

When the detail does not come out

1. "the project has no LSF wall". Typicals on a project without an LSF exterior wall. Draw the walls first.
2. "the project market does not have ...". The typical is called for, but a market number is missing, such as the raft recess or the gypsum clearance. The message lists what is missing. If no typical comes out, the app refuses the sheet and gives those reasons.
3. "the project market has no swaged joint model". DT27 to DT29 only come out when the project market has the swaged joint model and a machine with the swage tool.
4. "the outer board is not from the market (custom name), or the market does not have its spacing". A board typed by hand has no screw spacing, and DT21 does not come out. Pick the board from the market catalog.
5. "a standard detail does not fit on an A3". The app refuses the sheet: the drawing is larger than the paper.
6. "The project no longer has what DT21 shows." Red warning on the sheet when the model loses what the typical draws, for example when the outer board is removed from the wall. Remove the view or put the piece back.
7. A typical I expected does not appear. The project does not have the piece it shows, or the market does not have its numbers: DT27 needs the swaged joint, DT21 needs an outer board from the market, DT28 needs a nogging. Close the model and click again.
8. I clicked again and got an almost empty sheet. That is correct: the new sheet only takes what was missing. The six on sheet 1 are not repeated. With nothing new, the click opens the sheet that already exists.

It draws with the project profile; resistance stays in the calculation

The engine checks the limit states of each bar (see Reading the results). The detail draws the joint with the same piece the engine checked:

What stays with the designer

1. Anchorage to the foundation. The anchor reads "per the foundation design". The resistances of each anchorage assembly (NBR 16970-2, section 6) come from the foundation design and the report.
2. The designed connection. The screw in each note is the market rule. Where item 4.8 f) asks for a designed connection, it is sized separately and the number goes into the report.
3. The swaged joint. DT27 to DT29 are construction details: the note on each one says the analysis engine does not check the joint. The bar resistance is the one the engine checks in the calculation.
4. Checking against the 3D. Before sending the sheet to site, open each typical beside the 3D with the purple button, on the same wall. The 3D is the reference for every output.
5. Foundation and interfaces. DT1 draws the base on a raft slab with a recess. Recess, waterproofing and slab height follow the foundation design and NBR 16970-3 (draft), 4.2.2.

The path, in one line

Model closed (walls, noggings, boards, roof) → 3D with the purple button → wall selected → Joints (L1, L2, L3, L6, L9) → Typicals (up to six per sheet) → black and white → PDF.

The house sheets

• 6: typicals per A3 sheet, at most
• 1: joints sheet, five types
• 1:5: base, joints and layers
• A3: every detail sheet