Replace a Metal Roof in Vientiane: ປ່ຽນຫຼັງຄາ | Santiago

Mr Quyen - Santiago. Posted 03/11/2026

Renovated house with a new brown tile roof on a steel frame, Binh Phuoc, Vietnam

When is an old metal roof due for replacement?

A metal-sheet roof on a family house usually tells you when it is near the end. Look for these signs from inside the house and from a ladder at the eaves:

• Rust around the screw heads and along the laps between sheets
• Drips along the screw lines during rain
• Paint flaking off in patches and thin spots that give way when pressed
• Brown rust stains on the ceiling boards
• Rooms under the roof that are too hot to use in the afternoon, and rain too loud to talk over

Patching holes works for a while, but the rest of the sheet is the same age and the rust comes back somewhere else. Replacing the covering with ASA/PVC tile sheet removes the metal altogether: the sheet has no iron in it, so it cannot rust. In Santiago's tests the space under the sheet is about 6 – 8 °C cooler than under bare metal sheet and rain noise is about 80% lower.

What should be checked on the roof frame before ordering?

Metal sheet is stiffer than a plastic sheet and is often laid on purlins spaced far apart. ASA/PVC tile sheets need purlins less than 700 mm apart: 440 mm or 660 mm, so that each purlin sits under the foot of a tile step. When the old frame is sound, the rafters can usually stay and new purlins are added between the old ones. Check these points before you order:

• Rafters, timber or steel: straight, with no rot, termite damage or rust that has eaten through
• Old purlins: measure the spacing; clean and paint rusted steel purlins, or replace them
• Roof slope: 20 – 45%, which means a rise of 20 – 45 cm for each metre measured horizontally
• Top purlin: 15 – 18 cm below the ridge
• Walls that the roof runs into: mark them for vertical wall flashing

A 2.5 mm tile sheet weighs about 5.4 kg per m² of roof. Give that figure to your builder so the frame check is based on the real load.

How do I measure and order the sheet lengths?

Measure every slope on the roof itself, not from the original drawing. Old houses settle, and a veranda added later changes the lengths. Write the order slope by slope: number of sheets and length of each. Sheets are cut to length per order in 219 mm tile steps, and a sheet that comes out too short cannot be lengthened on site. Here is a worked example for a single-storey house with a gable roof. The ridge is 11 m long including the overhang at both gable ends, and each slope is 4.6 m from ridge to eave including the overhang.

Add ridge cap along the 11 m ridge, a ridge terminal at each end, eave sealing tile along both eaves, and vertical wall flashing anywhere the roof meets a wall, all in the roof colour. Standard colours are dark grey, red, blue, orange and chocolate.

Small yellow house with a new tile roof, Binh Phuoc, Vietnam

How can the family keep living in the house during the work?

A re-roof with tile sheets is done slope by slope, so the house never stands open. This order of work keeps the rooms usable:

1. Have all sheets, accessories and screws on site before the first old sheet comes off.
2. Strip only the part of one slope that can be covered again the same day.
3. Move beds, cupboards and electrical goods out of the rooms under that part, and cover the floor.
4. Fix the new purlins, then the tile sheets: pre-drill 6 mm holes, drive 70 mm screws through the top of the wave over a purlin, lap one wave sideways and never screw in the valley.
5. Keep a tarpaulin ready for any section still open at night or when rain comes in.
6. Finish with the ridge cap, ridge terminals, eave sealing tile and wall flashing.

Old metal sheets come off with rusted screws and sharp edges. Installers should wear gloves, and children should stay away from the area under the work.

How do I buy Santiago tile sheets in Vientiane?

Santiago exports from Vietnam by the container. One 40 ft container holds about 5,000 m of sheet, takes about 5 days to produce and can mix colours, profiles and accessories. The house in the example needs about 110 m, so a family buys through a roofing dealer or builder in Laos who imports; ask for Santiago ASA/PVC tile sheet by name and for the quality certificate (CQ) that comes with every lot. Shipments to Laos travel with a Form D certificate of origin, HS code 3925.90.00.

Santiago sends free samples (the buyer pays the courier) and installation videos, but it does not install. Prices are quoted per order in writing. The warranty is 10 years for sheets 2.5 mm and thicker installed as Santiago recommends, and the real service life is 25 – 30 years.

What does replacing an old metal roof with PVC sheets look like?

The short starts with a flame put to a stack of grey and red tile sheets, then Mr Quyen crouches on grey tile sheets in the Santiago factory. It ends on a blue warehouse roof where installers are laying new sheets, with Mr Quyen standing on the roof in a white helmet.

Heat test and a warehouse re-roof with uPVC sheets (Santiago video on YouTube).

More shorts for re-roofing in Vientiane

Three short clips in English, filmed by Santiago. Tap a video to play it here on the page.

Frequently asked questions

Do I need new purlins to replace a metal roof with PVC tile sheets?

Only where the old purlins are more than 700 mm apart or do not line up with the tile step. Santiago tile sheets need purlins 440 or 660 mm apart, each under the foot of a tile step.

How many PVC tile sheets does a 100 m² house roof need?

For a gable roof with an 11 m ridge and 4.6 m slopes: 24 sheets of 4.599 m (21 tile steps), about 101 m² of roof and about 400 – 510 screw sets.

How heavy is a PVC tile roof?

About 5.4 kg per m² of roof at 2.5 mm, so a 101 m² house roof carries about 550 kg of tile sheet.

Can the family stay in the house while the roof is replaced?

Yes, if the work goes one slope at a time and only the part that can be covered again the same day is opened.

How long is the warranty on Santiago tile sheets?

10 years for sheets 2.5 mm and thicker installed as Santiago recommends. Real service life is 25 – 30 years.

Read more

• Replacing a rusted metal roof with PVC sheets
• Roofing sheets in Laos: ASA/PVC vs metal
• Becoming a Santiago roofing distributor in Laos
• ASA/PVC roofing tile

Updated 03/11/2026. Santiago Import Export Co., Ltd, Vietnam. WhatsApp +84 935 391 495 (Mr. Quyen), hotline +84 965 437 316 (Mrs. Ly), email salessantiagoroofing@gmail.com.