Long-Lead Materials: Put Order Deadlines on Your Gantt

Why do Thai residential builds stall waiting for materials that appeared to be ordered on time?

Most Thai construction schedules track when a material needs to arrive on site — but never when the order needs to be placed. A contractor running a four-month renovation may have correctly planned that tiling starts in week nine, but if the order for a specific tile colour and size was placed only two weeks before install and the supplier needs four to five weeks to source that batch, the crew arrives in week nine to nothing. The tiles have not shipped. Tiling moves to week eleven, painting to week thirteen, second-fix fixtures to week fourteen. The project slipped not because of weather or rework, but because the order deadline was never on the Gantt. Every construction material has a supplier lead time. Working back from the install date by that lead time gives you an order deadline. That deadline must be a task on the plan, not a sticky note.

What are the standard supplier lead times for common Thai construction materials?

Lead times vary by material and supplier. Standard ceramic tiles from warehouse stock: one to two weeks. A colour or size not held in stock, or any imported tile: three to five weeks. Ready-made Thai-manufactured kitchen cabinets: three to five weeks. Custom-built kitchen or wardrobe units: five to eight weeks. Aluminium window and door frames fabricated to drawing: four to six weeks once drawings are confirmed. Standard sanitary ware from distributor stock: one to two weeks. Import-grade fixtures and fittings not stocked locally: four to eight weeks depending on origin. Structural steel standard sections from a mill: one to two weeks. Precast concrete elements: two to four weeks. These ranges assume normal supply; in high-demand periods, add one to two weeks to each figure and confirm stock availability before committing an install date to the owner.

How do you add a material order deadline as a task in the Gantt planning view?

Take the install date from the existing Gantt task for the trade using that material. Subtract the supplier lead time from that date. Create a new task called "Order — [material name]" at the resulting date and link it as a predecessor to the delivery task. The delivery task then links as a predecessor to the install task. The chain now reads: place order → material arrives on site → trade installs. If the install date shifts, the order and delivery tasks shift with it automatically. More importantly, if today's date passes the order deadline task and it is not yet marked complete in the Gantt planning view, the programme makes the risk visible immediately — without anyone needing to remember to chase the supplier on the right morning.

Three material categories with the longest lead times that stop a Thai build when ordered late

Three categories cause the most damage when ordered late. Custom and semi-custom furniture tops the list: kitchen units, built-in wardrobes, and bathroom vanities made to order in Thailand take five to eight weeks after final dimensions are confirmed. Aluminium or timber window and door frames in non-standard sizes follow: four to six weeks once drawings are approved. Specialist tiles — large-format imports, handmade cement tiles, or any colour not stocked in a warehouse — run three to five weeks. These three share a common risk: once you have passed their order window, no faster alternative exists that does not change the design intent. Putting their order deadlines on the Gantt planning view at project start is the single highest-return scheduling action a contractor can take before week one of construction.

A worked example: tile order delay on a 2.4-million-baht renovation in Pathum Thani

Khun Siriporn was managing a 2.4-million-baht renovation of a two-storey house in Pathum Thani on a 14-week programme. Tiling was scheduled to start in week eight. She called the supplier in week six — two weeks ahead, which had always been enough in the past. The supplier confirmed that the 60x60 light grey tile she had specified was out of stock; the next shipment would arrive in four to five weeks. The tiling crew could not start until week eleven at the earliest. Painting moved from week ten to week thirteen. Second-fix fixtures moved to week fourteen. The handover date shifted from week fourteen to week seventeen — three weeks lost from a call that came four weeks too late. Had Khun Siriporn placed the order in week two based on the supplier's stated lead time, the crew would never have stood idle and the owner would never have known there was a near miss.

How to protect the schedule when a key material cannot be substituted

Some materials cannot be swapped for an equivalent without the owner's agreement: a tile on the approved sample board, a kitchen unit in a specified finish, a window in a custom size. When a non-substitutable item is late from the supplier, the contractor has two options: wait, delaying every trade behind it, or source the same item from a secondary supplier, usually at higher cost. The secondary-source cost is often lower than the cost of a crew standing idle for a week. For any non-substitutable item, build an extra buffer into the order task: place the order two weeks earlier than the lead time would normally require. A four-week lead item becomes a six-week order deadline on the Gantt planning view. This buffer absorbs one round of supplier issues before the install date is at risk. Track the order confirmation as the first milestone in that task chain so there is a dated record that the obligation was met.

What do you do when a supplier delivers late even though you ordered on time?

Document the order date the moment it is placed. In the Gantt planning view in SiteBoard, update the order task's notes with the supplier name, order reference, and the confirmed delivery date they provided. When the delivery slips, you have a time-stamped record showing the contractor placed the order correctly and the delay originates with the supplier, not the site. This record matters in any conversation with an owner about a shifted handover date and is relevant if the contractor needs to seek compensation from the supplier for crew standing costs. Using the on-site progress updates feature in SiteBoard, the site supervisor logs what materials are on site each day. A delivery that has not yet arrived is a gap in the evidence trail — documented at the time it happens, not reconstructed three weeks later from memory.

FAQ: How far in advance should you order tiles for a Thai renovation project?

For warehouse-stock tiles in standard colours and sizes, two to three weeks before install is usually enough. For any tile that requires the supplier to source from their own manufacturer or from import, order at least four to six weeks before the scheduled install date. If the tile is imported, add the shipping time to that figure: tiles from Vietnam commonly take two to three weeks to ship; tiles from Spain or Italy can take six to ten weeks from ex-works. The safest practice for any tile not on a supplier's standard in-stock price list is to treat it as a six-week lead item until the supplier confirms availability in writing. Note the order deadline as a task in the Gantt planning view so it appears in the project timeline rather than only in a phone note or on a whiteboard.

FAQ: Should material order tasks appear on the Gantt that the owner sees through the owner sharing link?

Yes, for high-value and long-lead items. When the owner can see that the kitchen cabinet order was placed in week two and the delivery is expected in week seven, they understand why the install in week eight is achievable — and they can see if that delivery is at risk before the install date arrives. Owners who see order tasks on the shared Gantt are far less surprised when a material arrives late, because the plan shows the contractor ordered correctly and the issue came from the supplier. The owner sharing link in SiteBoard delivers a read-only view of the same plan the contractor manages. Adding order tasks for custom kitchen, tiles, windows, and sanitary ware costs nothing in terms of access management and removes one of the most common causes of owner distrust: a handover delay that arrives with no visible procurement history to explain it.

FAQ: How do you track whether a material order has actually been placed using SiteBoard?

Create a task for each major material order in the Gantt planning view with a deadline set at install date minus lead time. When the order is confirmed with the supplier, mark the task complete and add a note with the supplier contact, order reference, and the delivery date they confirmed. Attach a photo of the written order confirmation or the supplier reply. When the materials arrive on site, mark the delivery task complete and attach a photo of the delivery note. These two steps — order confirmed, delivery confirmed — create a documented procurement trail inside the same system the foreman uses for on-site progress updates daily. No separate spreadsheet or tracking file is required, and the project manager can see the status of every material order in the same view as task completion on site.