Timber Door, Window and Ventilator Frames 1995 Edition
The standard outlines specifications for timber frames used in doors, windows, and ventilators, emphasizing modular sizing, material standards, joinery techniques, and finishing processes. It serves manufacturers, architects, and engineers to ensure frames are durable, dimensionally precise, and environmentally compliant, including requirements for ECO Mark certification.
The standard outlines specifications for timber frames used in doors, windows, and ventilators, emphasizing modular sizing, material standards, joinery techniques, and finishing processes. It serves manufacturers, architects, and engineers to ensure frames are durable, dimensionally precise, and environmentally compliant, including requirements for ECO Mark certification.
Audience
Who Uses This Standard
Structural design engineers
Architectural professionals
Building contractors
Producers of timber frames
Quality assurance inspectors
Suppliers of construction materials
Environmental regulatory personnel
Contents
Key Topics Covered
✓Modular and custom frame sizing
✓Approved timber species and allowable imperfections
✓Joinery techniques such as dovetail and mortice-tenon
✓Specifications for holdfasts and metal fasteners
✓Surface finishing and priming protocols
✓Frame identification and labeling system
✓Sampling procedures and inspection standards
✓Environmental compliance including ECO Mark criteria
✓Timber treatment and preservation methods
✓Permissible dimensional tolerances and workmanship quality
✓Information requirements for ordering
✓Imported timber species and associated treatment guidelines
Structure
Table of Contents
1Scope and Application
2Sampling Procedures and Inspection Methods
3Acceptance Criteria for Quality Conformance
4Materials Used and Allowed Timber Defects
5Joinery Techniques and Assembly Guidelines
6Frame Dimensions and Identification System
7Placement and Specifications of Metallic Fasteners
8Surface Treatment and Priming Requirements
9Details Required from Purchasers
10Additional ECO Mark Certification Requirements
Annex ARelated Indian Standards
Annex BApproved Imported Timber Species
Annex CSampling Methodology
Annex DCommittee Members and Responsibilities
Frequently Asked
Popular Questions About IS 4021
?What modular dimensions are specified for timber frames?▼
The standard defines frame dimensions using modular units to standardize components, allowing modular or non-modular sizes for width and height but fixed cross-sectional dimensions. Width tolerances are ±3 mm and thickness tolerances are ±2 mm, ensuring interchangeability and manufacturing ease.
?Which timber species are allowed and what treatments must they undergo?▼
Timber must be properly seasoned per IS 1141 and treated with preservatives according to IS 401, except for durable heartwood species marked with '+', which require no treatment. Imported species listed include Afrormosia and Iroko (durable) as well as others requiring preservation. Poorly treatable timbers need additional PCP solvent treatment post-construction to ensure minimum preservative penetration.
?What types of joints should be used for assembling timber frames?▼
Recommended joinery includes single dovetail joints, closed mortice and tenon joints with 'horns' for built-in frames, and haunched mortice and tenon joints for non-built-in frames. All joints must be accurately fitted, glued, and pinned with hardwood or bamboo pins to ensure strength and durability.
?How are combined door, window, and ventilator frames designated?▼
Combined frames use a modular designation format indicating width in modules, frame type codes (D for door, W for window, V for ventilator), shutter type (S for single, T for double), and height in modules. Dimensions adopt the highest recommended size among components to maintain uniformity.
?What environmental criteria must be met for ECO Mark certification?▼
ECO Mark certification requires that door shutters be manufactured from agricultural/industrial waste, wood residues, or wood from non-natural forest sources compliant with IS 12896. Products must fulfill quality and environmental standards, with manufacturers providing documentation such as environmental clearances under relevant pollution control laws. The product must bear both the BIS Standard Mark and the ECO Mark.
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