T1-11 Siding: Specifications, Grades and How to Import from Brazil

May 17, 2026·7 min readplywoodUSA

T1-11 (also written T111 or Texture 1-11) is a grooved plywood siding panel that has been a staple of North American residential construction for decades. It is used on house exteriors, barns, sheds, garages, and outbuildings across the US and Canada. Brazil is one of the leading exporters of T1-11 to the US market.

What is T1-11?

T1-11 is a structural panel siding product — plywood with vertical grooves machined into the face at regular intervals. The grooves create a board-and-batten visual effect without the labour of installing individual boards. The panel is used as both structural sheathing and finished exterior cladding in one layer.

Key characteristics:

Grooved face (vertical grooves only)
Structural plywood panel — provides racking resistance
WBP exterior phenolic glue bond
Ready to prime and paint on installation

Specifications

Specification	Standard value
Typical thickness	9.5mm (3/8"), 11mm (7/16"), 15mm (19/32")
Sheet size	1220×2440mm (4×8 ft)
Groove pattern	4" o.c. (on centre) or 8" o.c.
Groove width	Approx. 3mm (1/8")
Groove depth	Approx. 6mm (1/4")
Species	Pinus elliottii / Pinus taeda
Glue bond	WBP Exterior Phenolic
Surface	Rough-sawn texture face (brushed or sanded options)
Grade standard	APA Rated Siding / PS1-09

Groove patterns

4" o.c.: Grooves every 4 inches across the panel width. Creates a narrower board appearance. Most popular for residential housing.

8" o.c.: Grooves every 8 inches. Creates a wider board appearance. Common for agricultural buildings and sheds.

CARB P2 and formaldehyde compliance

T1-11 exported to the US must comply with CARB P2 / TSCA Title VI formaldehyde emission standards. All T1-11 produced by our Brazilian mills for the US market is certified by an EPA-approved third-party certifier (Bureau Veritas, SGS, or Intertek).

Documentation provided:

CARB P2 / TSCA Title VI compliance certificate
Third-party emission test report
Mill-specific CARB certificate

How to import T1-11 from Brazil

Lead time: 4–6 weeks production + 12–16 days transit to Gulf of Mexico ports (Houston, New Orleans).

Container loading: A standard 40'HC container holds approximately 800–1,000 sheets of 9.5mm T1-11 (4×8 ft), depending on stacking configuration.

MOQ: 1 FCL (minimum). A 40'HC is the standard container for T1-11 due to panel size — T1-11 cannot practically be consolidated in LCL.

Pricing: FOB Paranaguá. Contact us for current pricing — rates vary with Brazilian exchange rate and production volume.

Documentation package

Every T1-11 shipment from EBP includes:

Commercial invoice + packing list
Bill of Lading
Certificate of Origin (Brazil)
Phytosanitary certificate (MAPA)
ISPM 15 heat treatment certificate
CARB P2 / TSCA Title VI compliance certificate
FSC transaction certificate (if FSC grade ordered)