RF Roof

To provide a structurally sound and watertight covering over the building.

It INCLUDES portal frames; roof construction; gable and other walls in roof spaces; parapet walls and roof balustrades; thermal insulation roof lights and dormers with their sun screenings; eaves, verges and fascias; rainwater goods; internal storm water drainage runs; awnings and open lean-to roofs; all protective non-decorative coatings.

It EXCLUDES rainwater goods to balconies and other unenclosed floor areas (UF); all non-structural work associated with the internal services; independent roofs to exposed attached external stairs (SC).

Verify Element Properties

The Roof category was filtered using Visibility/Graphics (VV/VG) from the linked architectural model, Snowdon Towers Sample Architectural Rev A-Copy.rvt, rather than from the structural model.

Generate the QTO Schedule line items by running the Run QTO command on the Roof category, then use Select Linked to verify that all items shown on screen have been extracted.

Tick this box to check for any existing elements:

A 9″ concrete slab appears under both the Existing and New Construction phases. Send a query or RFI to the modeller to confirm whether it exists and whether any special treatment is required.

Rainwater goods and internal stormwater drainage runs are normally designed under Plumbing, so link and verify the Plumbing model.

Run QTO on:

1. MEP: ductwork, pipework, cable tray and all fittings. The QTO Schedule shows three line items for roof drainage (6″ dia. cast iron pipework).
2. Plumbing fixtures: basins, toilets and tapware, plus the family Roof Drain – 12″ Strainer – 6″ Drain.

ANZSMM Measurement Rules

ANZSMM 16. Roofing states the following measurement rules:

Measurement rules:

M3. measure net area to be covered unless stated otherwise including under ridges, flashings and similar items

M18. measure net length along centre line of pipes over all bends, junctions, offsets and similar items

Roof coverings are measured in m², with slopes over 10° stated separately. Downpipes are measured in linear metres (m). Fittings (bends, junctions, offsets, shoes and similar items) are enumerated (No.). In this project, all fittings are grouped into one (1) item.

To Take Note

• The model may contain existing elements that are not clearly marked in their Phasing properties, or that belong to alteration or renovation works.
• If there are any existing elements, check whether they need treatment before they can receive new works.
• The Coverage Audit serves as a QA fallback for excluding those elements and closing out the measurement. Raise queries or RFIs with the modeller to resolve any ambiguities.
• Roof drainage falls under the Plumbing scope. Measure in sequence from the roof down to the lower-ground outlet sump.

Measurement and Billing

The extraction covers a single category, Roof. The QTO Schedule shows six line items in total, two of which are 6″ thick cast in-situ slabs that require formwork.

Add Formwork to the Run QTO extraction. The schedule then shows ten line items in total, ready for linking to the Workbook.

Plumbing

Roof drainage includes pipework and fittings. Filter the view to show the following categories: Pipe Fittings, Pipes and Plumbing Fixtures, as shown below.

You will see thirteen (13) 12″ strainers. These form the uppermost inlets of the roof drainage system. Extracting the piping quantities is straightforward.

Use Select Linked to pick any of the drainage pipes, and its properties will be displayed. Look for the Material (System Type: Roof Drainage 1), then link all three (3) line items to the Workbook.

For the pipe fittings, use a similar method to the piping to locate your line items in the QTO Schedule. Starting from the strainer and working downwards, use Select Linked to pick the first bend, elbow or tee below the strainer, and note its ElementId (e.g. #1697269; see Select Linked: Drainage Bend above).

Enter this number into the QTO Search box to filter for the line item containing this ElementId, then link it to the Workbook. Repeat the process for tees and other fittings.

Your completed Roof elements in the Workbook and the exported BQ should look like this:

Quality Assurance (QA) Checks

Summary

Category	Elements	QTO Schedule	Linked to Workbook
Roof (including Formwork)	– Cast in-situ roof slab – Roof	10 lines	All 10 lines linked
Floors (including Formwork)	– Metal deck roofing	4 lines	All 4 lines linked
Plumbing	– Downpipes – Fittings	– 3 lines -69 lines	All 72 lines linked
Different Phase Elements ( Excluded in Coverage Audit)	9″ concrete roof slabs	6 lines	All 6 lines Excluded