Replace Asbestos Roof Sheets with PVC: Order of Work

Mr Quyen - Santiago. Posted 14/11/2026

An old asbestos-cement roof has to be taken off by a licensed asbestos removal specialist, under the rules that apply where you live, before a new roof goes on. After that a builder checks the frame and closes the purlins to less than 700 mm apart, and the new ASA/PVC sheets are laid. Santiago supplies the new sheets and accessories only. It does not remove old roofs and does not install.

New tile-sheet roof next to an older roof, Vietnam

New tile-sheet roof next to an older roof, Vietnam

Can I remove asbestos roof sheets myself?

No. Removing asbestos-cement sheets is not a job for the owner or for a general roofer. Breaking, cutting, drilling or even dropping old sheets can release fibres, and in most countries the work is controlled by law: who may do it, how the sheets are wrapped and carried, and where they are disposed of. Ask your local authority, or the health, environment or labour office that covers asbestos in your country, how to find a licensed contractor.

Some owners ask whether new sheets can simply go on top of the old ones. That decision belongs to the licensed specialist and your local rules, not to the roof sheet supplier. Fixing new sheets through old ones means drilling the old sheets, and drilling is one of the things that releases fibres. Santiago gives no advice on removal, over-roofing or disposal.

What is the right order of work?

Stage	Who does it	What to have ready
1. Survey of the old roof	Licensed asbestos surveyor or contractor, as your rules require	Access to the roof and the rooms below
2. Notices and permits	Licensed contractor, local authority	Whatever paperwork your area asks for
3. Removal and disposal	Licensed removal specialist	Rooms below cleared or covered as the specialist instructs
4. Frame check	Builder or engineer	Old purlin spacing and roof slope measured
5. Purlin work	Builder	Purlins less than 700 mm apart; 440 or 660 mm for the tile sheet
6. Lay the new roof	Installer	Sheets, accessories, 70 mm screws with ASA caps, Santiago installation videos

Timing is worth planning. Production of a Santiago order takes about 5 days, and sea freight and customs come on top. Many builders measure the frame from inside the building before removal, so the new sheets are ordered early and the building stands open for as short a time as possible. The final purlin check still happens once the old sheets are off.

Brick building with a sheet roof, Vietnam

Brick building with a sheet roof, Vietnam

Can the old frame carry the new ASA/PVC roof?

Often the rafters or trusses stay and the purlins change. The purlin spacing on an old roof was set for the old sheets, so measure it rather than assume it fits. ASA/PVC is softer than steel and needs purlins less than 700 mm apart; for the tile sheet that means 440 or 660 mm, with one purlin under the foot of each 219 mm tile step. The top purlin sits 15 – 18 cm below the ridge.

A 2.5 mm tile sheet weighs about 5.4 kg per m² of roof. Santiago has no weight comparison with asbestos-cement sheet to publish, so the builder or engineer judges the frame on what is actually there: replace split or rotten timber and badly rusted steel. Check the slope too. The sheets need 20 – 45%; on an old roof flatter than 20%, the tile sheet is not recommended because water runs off too slowly.

Tile sheet or corrugated sheet for the new roof?

House, cottage or ancestral house: the Spanish-style tile sheet, 1.05 m wide, 0.96 m cover, cut to length in 219 mm steps.
Workshop, store or farm building that had corrugated sheets: 5-wave (1.08/1.00 m), 6-wave (1.06/0.95 m) or 11-wave (1.05/1.00 m) ASA/PVC sheet.
A shed that needs daylight: add skylight sheets on 5 – 10% of the roof.

Ridge caps, hip ridges, three-way and four-way pieces, ridge terminals, eave sealing tiles and vertical wall flashing come in the same colours as the sheets, so the old ridge and edge pieces are not reused.

Side wall of a brick building below its roof, Vietnam

Side wall of a brick building below its roof, Vietnam

Will the new roof be cooler and quieter?

Santiago's tests compare ASA/PVC with bare metal sheet: about 6 – 8 °C cooler under the roof and about 80% less rain noise. Santiago has not tested against asbestos-cement sheet, so we give no figure for that comparison. What the new roof does bring is a sheet with no metal in it to rust, an ASA colour layer that showed no change after 2,000 hours of artificial UV and is rated for 30 years, and a real service life of 25 – 30 years. The warranty is 10 years for 2.5 mm and thicker sheet installed as Santiago recommends.

Example: sheet list for a 10 m brick building

A brick building 10.0 m long with a gable roof, 0.2 m overhang at each gable end and 3.5 m along the slope on each face, re-roofed with tile sheet after the old roof has been removed.

Item	Working	Result
Roof length	10.0 m + 2 × 0.2 m	10.4 m
Sheets per face	10.4 m ÷ 0.96 m = 10.8, round up	11 sheets
Sheet length	3.5 m ÷ 0.219 m = 15.98, round up to 16 steps	3.504 m
Sheets for the roof	11 × 2 faces	22 sheets, about 77 running metres
Roof area	10.4 m × 3.5 m × 2	about 73 m²
Purlin rows per face	top row 15 – 18 cm below the ridge	about 6 at 660 mm or 9 at 440 mm
Screw sets with ASA caps	73 m² × 4 – 5 per m²	about 290 – 365
Ridge cap and ridge terminals	Along the ridge	10.4 m and 2 terminals
Eave drip tile	Both eaves	20.8 m
Sheet weight	73 m² × 5.4 kg	about 390 kg

Screws go through the top of the wave over a purlin, into pre-drilled 6 mm holes, never in the valley. Each sheet laps the next by one wave.

Installers working at the edge of a tile-sheet roof, Vietnam

Installers working at the edge of a tile-sheet roof, Vietnam

What does a replacement roof cost, and how is it bought?

People search for "roofing plastic asbestos sheet price", but no single figure covers the job. The total is made of separate parts: the licensed survey, removal and disposal; frame and purlin repairs; the new sheets, accessories and screws; freight and duty; and the installer. Santiago quotes its part per order in writing, by profile, thickness, colour, sheet lengths and accessories.

Santiago sells for export by the 40 ft container, about 5,000 m of sheet with colours, profiles and accessories mixed. One building is far smaller than that, so owners normally buy through a dealer, importer or builder in their own country. Free samples are available; the buyer pays the courier.

Why do old roofs get replaced, and what changes with a tile sheet?

Mr Quyen holds a white tile sheet in the Santiago factory in Vietnam and explains in English, with captions, why bare metal roofs are hot, noisy in rain and costly to repair. The short then moves to a red tile roof on a house and a finished grey tile roof beside the gutter.

Heat and rain noise: Santiago ASA/uPVC roofing explained (Santiago video on YouTube).

Santiago – a leading exporter of ASA/PVC roofing from Vietnam

Santiago roofing is produced and loaded into containers at our factory in Vietnam. It has been exported to India since 2023, Thailand since 2024 and the USA since 2025. Every export shipment comes with a commercial invoice, packing list, bill of lading and a certificate of origin (C/O) issued by Vietnam's Ministry of Industry and Trade, which importers use to claim the duty preference of their trade agreement.

Item	Details
HS code	3925.90.00 (ASA/PVC roofing sheets)
Certificate of origin	Form D (ASEAN), Form AI (India), Form AK / VK (Korea), Form AJ / VJ (Japan), Form VC (Chile), CPTPP proof of origin
Shipped from	Vietnam, by container

Certificate of origin Form AI (ASEAN–India) for Santiago ASA/PVC roofing sheets, HS 39259000, certified on 24 September 2026. Buyer details are hidden.

Certificate of origin Form AI (ASEAN–India) for Santiago ASA/PVC roofing sheets, HS 39259000, certified on 24 September 2026. Buyer details are hidden.

The Santiago team beside a loaded export container at the factory, November 2024

Loading Santiago roof tiles into an export container

Frequently asked questions

Can I remove an asbestos roof myself?

No. Old asbestos-cement sheets must be removed by a licensed specialist under your local rules. Ask your local authority how to find one. Santiago only supplies the new sheets.

What can replace asbestos roof sheets?

For houses, a Spanish-style ASA/PVC tile sheet; for workshops, stores and farm buildings, 5, 6 or 11-wave ASA/PVC sheet. Both are 2.5 – 3.0 mm thick and contain no metal.

Can new PVC sheets go on the old roof frame?

Often, once a builder has checked it. Purlins must be less than 700 mm apart (440 or 660 mm for the tile sheet), the top purlin 15 – 18 cm below the ridge, and the slope 20 – 45%.

Is a PVC roof cooler than an asbestos roof?

Santiago has only tested against bare metal sheet: about 6 – 8 °C cooler and about 80% less rain noise. There is no Santiago test against asbestos-cement sheet.

What is the price of plastic sheets to replace an asbestos roof?

Santiago quotes per order in writing. Removal and disposal by a licensed specialist, frame repairs, freight, duty and installation are separate costs.