Material Selection and Pricing for Lombok Construction Projects

Material Selection and Pricing

Procurement decisions directly affect structural performance, durability, and compliance outcomes in Lombok. Below is a practical breakdown of commonly used materials and components—fasteners, steel profiles, roofing, drainage, electrical fittings, coatings, and pavingorganized for clarity. Prices provided reflect the list you shared and are shown with their stated units. In practice, prices on Lombok vary with availability, shipping from Java/Bali, and order volume. Verification at time of purchase is essential.

1) Structural Fasteners and Connectors

Fasteners determine how load paths are transferred through trusses, frames, and roofing systems. For coastal and high-humidity environments, ensure correct diameter, grade, and corrosion protection.

Steel Truss Bolts (Baut Kuda-kuda Baja)

Used in roof truss assemblies; diameter and length must match design.

Item	Spec	Unit	Price
Baut Kuda-kuda Baja Ø 17 mm (25 cm)	Ø17 × 25 cm	Buah	23,467
Baut Kuda-kuda Baja Ø 17 mm (30 cm)	Ø17 × 30 cm	Buah	52,146

Notes:

• Match bolt diameter with hole sizing and plate thickness to avoid slippage.
• Use washers and locking nuts to maintain pretension under thermal cycling.

SDS Screws (Baut SDS) – for sheet/steel fixing

Item	Spec	Unit	Price
Baut SDS 8	Ø8	—	23,000
Baut SDS 12	Ø12	—	20,000

In practice:  Self-drilling screws need appropriate coating (galvanized or alloy) to resist corrosion, especially beneath roofing sheets.

2) Lightweight Steel Profiles (Galvalume)

Galvalume C-channel sections are widely used for purlins and light framing. Thickness and geometry affect deflection and corrosion life.

Item	Spec	Unit	Price
Canal C 75–75 Galvalume	thickness 0.45 mm (noted “0,050 Uk 0,45 0,915”)	Batang	104,292
Canal C 75–60 Galvalume	—	Batang	52,146
Canal C 75–80 Galvalume	—	Batang	167,352

Notes:

• Verify actual thickness (TCT/BMT) and coating weight; documentation must align with design loads.
• Store off the ground and under cover to avoid edge rust and coating damage.

3) Pipes and Precast (Buis Sigaran)

Buis (precast concrete rings/pipes) are typically used for drainage, wells, or culverts. Ensure specification matches hydraulic and load requirements.

Item	Spec	Unit	Price
Buis Sigaran Ø 30, p = 1 m	Ø30 cm × 1 m	Buah	173,386
Buis Sigaran Ø 15, p = 1 m	Ø15 cm × 1 m	Buah	166,868
Buis Sigaran Ø 20, p = 1 m	Ø20 cm × 1 m	Buah	160,349
Buis Sigaran Ø 25, p = 0,50 cm*	Ø25 cm × 0.5 m	Buah	91,256

* Interpreted as 0.5 m length.

In practice:  Confirm compressive strength and wall thickness; avoid substitutions as they impact hydraulic capacity and backfill requirements.

4) Roofing and Ridge Accessories

Roofing selection must consider wind uplift, salt exposure, and rain intensity typical in Lombok.

Item	Spec	Unit	Price
Asbes Gelombang Besar	Large corrugated sheets	Lembar	45,629
Metal Polos Warna 0,22 (1 × 5 m)	Painted sheet, 0.22 mm	M	36,503
Bubungan – Ujung (Ridge end)	Ridge accessory	Buah	57,361
Bubungan – Tepi (Ridge edge)	Ridge accessory	Buah	14,992
Bubungan – Starter	Ridge starter	Buah	57,361
Bubungan – Segitiga	Ridge triangle	Buah	57,361
Bubungan – Atas	Ridge top	Buah	16,296

Notes:

• For metal roofing, 0.22 mm is thin; confirm designer’s minimum thickness.
• Ridge accessories must be compatible with sheet profiles to prevent leaks.

5) Roof Tiles (Genteng)

Ceramic and pressed tiles are common for villas; their weight influences truss design.

Item	Spec	Unit	Price
Genteng Keramik	Ceramic tile	Buah	24,379
Pejaten Lokal	Local tile	Buah	3,260
Pres Manual	Manually pressed	Buah	1,956
Pejaten	—	Buah	4,563
Mantili Besar	Large type	Buah	3,911
Silang Kodok Palembang	Patterned tile	Buah	3,260

In practice:  Tile selection drives truss spacing and batten sizing; ensure supplier consistency to avoid color mismatch and variable absorption.

6) Drainage

Well-designed drainage reduces maintenance and structural risk.

Item	Spec	Unit	Price
Talang PVC Kotak	Box-section gutter	—	80,433

Notes:

• Confirm flow capacity and bracket spacing; UV resistance is important in tropical sun.

7) Electrical Fittings and Controls

Fit-out quality affects usability and maintenance cycles.

Item	Spec	Unit	Price
Fitting lampu no.210	Lamp holder	Buah	19,556
Fitting lampu no.216	Lamp holder	Buah	14,471
Fitting lampu no.220	Lamp holder	Buah	26,073
Fitting lampu no.226	Lamp holder	Buah	15,644
Lampu Otomatis (Sensor Cahaya)	Photo-sensor light	Buah	72,353
Fitting Putih Keramik	Ceramic fitting	Buah	37,806
Multimedia Controller / traffic light	Controller	Unit	847,372
Controler traffic light (set)	System set	Set	8,473,718

In practice:  Ensure proper IP ratings in outdoor zones and document brand/model to maintain consistency.

8) Coatings and Paints

Protective coatings extend steel life; application method matters.

Item	Spec	Unit	Price
Cat semprot Danagolf D10 0,1500	Spray paint/coating	Botol	30,348

Notes:

• Confirm technical datasheet (coverage, VOC, curing). Surface prep is critical for adhesion in humid climates.

9) Framing, Doors, and Miscellaneous

Item	Spec	Unit	Price
Bingkai Lampu / Promosi	Frame (vinyl display)	Buah	9,454,715
Pabrikasi Pintu viber polos	Plain fib(e)r door fabrication	—	162,96 *
Cok Roll 10 M	10 m roll	Pcs	229

* The door line in the provided list is unclear; confirm specification and unit before use.

10) Paving Blocks (Outdoor Surfaces)

Strength class and compaction quality determine performance under load and rainfall.

Item	Spec	Unit	Price
Paving Blok Manual	Manual press	M²	78,219
Paving Blok Tebal 6 cm K100	6 cm, class K100	M²	93,863
Paving Blok Tebal 6 cm K200	6 cm, class K200	M²	113,418

In practice:

• Subbase and bedding sand must be controlled (gradation and compaction).
• Edge restraints reduce migration and settlement.

Procurement Reality in Lombok

Availability and Substitution: Materials such as higher-thickness galvalume, certified bolts, and specific roof tiles may not be available at short notice. Unverified substitutions create structural risk and complicate compliance inspections.

Supplier Verification: Request product certificates (SNI or recognized equivalents), mill test reports for steel, and datasheets for coatings and electrical fittings. Avoid informal suppliers where documentation is not consistent.

Logistics and Storage: Shipping from Java/Bali affects lead times and cost. Plan bulk orders for core structural items and maintain controlled storage to prevent corrosion and theft.

Quality Control on Site: Conduct basic tests (e.g., fastener torque checks, coating thickness readings, visual inspection of roofing overlaps, water tests on gutters). Document installation to align with PBG/SLF requirements post-construction.

Compliance Considerations (Practical)

While permit systems (OSS for submissions, PBG for building approval, SLF for post-completion function certification) are administrative, inspectors evaluate outcomes that reflect material choices and workmanship. Using thin roofing, ungraded purlins, or uncertified fasteners can trigger remediation or delay certifications. Clear specifications, supplier credentials, and site records support smoother approvals.

Working Approach We Recommend

1. Define Specifications Early
• For truss bolts: diameter, grade, coating.
• For galvalume: section (75–60 / 75–75 / 75–80), thickness (BMT/TCT), coating weight.
• For paving: compressive class (K100/K200), thickness, subbase build-up.
2. Lock Suppliers and Lead Times
• Identify primary and backup suppliers in Lombok/Mataram and Java/Bali.
• Place orders for structural items first to avoid substitutions.
3. Document Everything
• Keep certificates, invoices, delivery notes, and site photos.
• Record installation checks (torque, alignment, overlap dimensions).
4. Test Critical Components
• Pull-out tests for SDS screws where applicable.
• Visual and leak testing for roofing and gutters.
• Field density tests for paving subbase, if loads are high.
5. Budget with Contingency
• Prices shown above are item-level references from your list.
• Include 5–10% contingency for logistics and availability.
• Revalidate prices before tender or purchase order issuance.

Notes on the Price List Provided

• Some lines are incomplete or duplicated (e.g., multiple “Bubungan” entries, “—” items, or unclear units). Where possible, we mapped items to typical usage and kept the listed prices.
• Items such as  Canal C  have prices listed per  Batang ; confirm length per batang to avoid quantity errors.
• For specialty items (e.g.,  traffic light controller sets ), installation and programming are separate costs not reflected in material unit pricing.

Summary

Material choices and procurement discipline have direct impact on structural reliability and regulatory compliance in Lombok. The tables above organize key items—bolts, SDS screws, galvalume profiles, buis, roofing accessories, tiles, gutters, fittings, coatings, and paving—with the prices you supplied. Before purchasing, verify specifications, units, and documentation, and plan for lead times due to island logistics. Consistency in materials and records reduces risk and supports a smoother PBG/SLF process after construction.